This is a really good topic. I can add one thing they may help clarify the issue. There's no standard that manufacturers have to use to measure an amps power. Each manufacturer does it their own way. That's why you can go to Walmart and get a 1000 watt home theater in a box for $99. The reality is, if you took 5 amps all rated for the same power, like 100 watts into 8 ohms, every one will measure differently if you did them all the same way. Its been a problem in the industry for years.
I was conversing with a soundman friend about this very topic today - most timely, Dave! We talked about how the digital guitar processor, recorded into software, processed by plugins, played back through a digital mixer into digital amps is "removing the heavy cream, then the light cream, then the 4% milkfat, then 2%, and we're left with nonfat milk" in sound reproduction. I just missed an auction for a Crown MacroTech 5002 Anniversary Edition with a copper faceplate that sold for $1700. Crown only made 200 of them. Of course, then I'd need to buy some passive JBL's (again) to go with it. We're looking forward to this series, Dave, thank you very much for your great dives into our beloved passion.
So true, I used to demo for people a 30 Watt per channel stereo amplifier and showed it put out more clean sound than a cheaper 250 Watt amplifier. The the 30 Watt amplifier was rated into 4 ohms both channels driven at less than 0.1% THD. Clean 60 Watts RMS in a store is quite loud. The 250 watt amp on the other hand was listed a total peak power with no mention of distortion level. On an oxcilioscope, the 30 watt amp put out a little over twice the voltage non-clipped than the 250 Watt amp, or 6DB more clean power out of the speaker. RMS watts specified into a restive load and at a specified distortion level and sine wave is the way to compare apples to apples. In the repair shop, used to torture test amplifiers by running them at their rated power into a dummy load. Not all amps survived. Those that did were stocked. Those that failed to perform to spec were returned. An amp that will do peak un-distorted power for 15 minutes is a good amp. The numbers that interested me most are not published. How many volts peak to peak does the amp clip into 8 ohms, 4 ohms, 2 ohms, and one ohm if applicable. Can it sustain the peak value for a long time? I used to measure this. Double the voltage = twice the voltage at twice the current into a fixed load or 6 DB more power.EG a 50 volt signal is 6 DB less than a 100 Volt signal. This is the difference between a 100 Watt amp and a 400 Watt amp.
I’m so glad I found this video. I’ve been putting my old stereo system back in play but and so far I’ve back off a couple amps because I don’t want to blow my speakers or mess up my system. I definitely need 1000 watts even if I need new speakers lets go😂
Hey Dave it's great your going to have a deep dive into this topic, what makes it more interesting is how there are similar issues and confusion with regard to how the loudspeakers are dealing with the power fed to them, I'm guessing that we will learn quite a bit about that too along the way. Think I'm gonna need some popcorn ; )
Great stuff, Dave. I will make you smile. Back in the early 80's.... Hill DX700 running 2 ohm per channel into 4 Gauss 4560's and 4 JBL K120 . Incredible amp. 😊😊
Those hill amps were cool. One of the first to employ internal crossovers, ultra compact and drive low impedance loads. Hill deserves more credit for being cutting edge than they get.
One other thing that changed is Slew rates, I've been updating the IC's in my Urei 527's to modern IC's for faster slew rates. In terms of those older amps with big heavy transformers versus the modern stuff with lightweight torodials I never considered how long they could put out RMS very awesome video as always!
Dave rat is an American hero, specializing in audio. A paramount definition of mad scientist. Cant get enough of this guy, I would watch an 8 hour video of him exploring something as bland as e-tape vs gaff tape because he would make it fascinating, he should really start his own school, it would bankrupt fullsail and ultimately exponentially progress the industry via its graduates
I'm a bit of a sucker for Crest Audio amps, So I'm extremely intrigued as to what the results are. I've had a lot of experience with their CA series and have always been pleased with the results, especially when driving subs.
@@DaveRat yes of coarse you built it yourself. Man of many talents I swear to you this is my favorite emoji on the planet Earth trying to imagine a stack like that of supersubs. Wouod that cause an earthquake? Omg...
Glad to see these topics brought up. Pat Brown and has worked a lot to develop a standard way of evaluating amplifiers and speaker ratings. See Common Amplifier Format (CAF). Then you have the rabbit hole of loudspeaker 'power' ratings. In reality the term 'power' is not the best term. In reality we care about how much voltage an amplifier can deliver and over what time frame (yes totally on board with the limitation of many modern designs to deliver full voltage for less than a second); and for many uses that is fine. But sometimes you need an amp that delivers full power for a second or two. Also getting people to understand that with most music (or voice) the real power draw on an amp is going to be at 1/4 to 1/3 the stated power rating is a challenge (when in use at at full volume). Good info. You have worked through this in the trenches.
@@DaveRat two areas that I have seen modern digital amps perform as lees than expected is with EDM where there is a bass 'drop' with a sine wave component , and artificial reverb, the crest factor of reverberation is about as low as peaked clip noise. Crest factor is a whole 'nother rabbit hole. ;-)
I have an early 70’s Acoustic bass amp that’s “only “ 300 ish watts 😎 it’ll flap your trousers at 5 meters away through Ampeg cab and the amp almost vibrates itself off the top 👍🏻 I’ve also got a Bugera Nuke that’s supposed to be powerful and there is no comparison, the old amp blows it away completely:-) and it has more character 👍🏻
It's all about using the right tool for the job. I like the old amps and also a good class D app can really light up a system when you transition from the older amps
Interesting. Will see what shows up in tests. Typically gear tends to be defined by its ability to deal with the extremes. I would love to see audio gear able to handle a full octave above and below the intended usage. So gear that can do 10 to 40k will be more than fine for 20 to 20. Narrowing the freq range tends to make the job easier on the gear.
It is always a pleasure to here your analogies and thought processes, so on this point, would you tend to have a set ratio of amp wattage, say 50% of overall power to bass, 30% for mids, and 20% for HF? I ask as I am trying to build 2 small audio systems of 2-way and 4-way active speakers.@@DaveRat
Depends on your crossover points and how many octaves are being powered by each band. Also you can get away with a lot more compression/limiting on low frequencies without being audible then you can on the highs for protection. So for the highs you want extra voltage swing to maintain transients. Currently the industry standard is to have the same amp for all the bands. Modern amps Will share the power supply energy. Using a four-channel amp with a 15 on channel 1 and another 15 on channel 2 and 4 x 6" on channel 3 and three 2-in on channel 4 is how the K1 is powered. Similar power configurations are very common and just using a multi-channel amp the power everything is easy and kind of a cool way to go
Thanks for the video. Recently I bought an old amp at auction to fool around with and i was wondering if you could help shed some light on it. Its about 18 years old and made in Australia by a now-defunct company called MSR. There's no manual and details about it are slim. What I do know is on the back it reads "This amplifier produces 850W RMS into 4ohms per channel continuously, 1600WRMS bursts." And on the inside, instead of a handful of large capacitors it has about 30 small ones per channel. If you don't mind, I've got two questions; a) what kind of mutant am I dealing with? and b) could you recommend an appropriate sub driver for small parties? Cheers
Lots of small caps vs fewer big ones is not an issue. Its the total capacitance that stores some energy to improve output power from sagging. as far as subs. too many options and I think that can be better answered in like a reddit post or an online audio forum where ya share more info and people can assist
I had to take out the IEC power connectors and hardwired cords of the proper guage into all my amplifiers. I haven't had an amplifier failure since then. The IEC power connectors are THE number one cause of amplifier failures as they are only meant to carry 10 amps. The 20 amp IEC only carries 15 amps. The power lights don't dim on my amplifiers any more. If you don't believe me, put a volt meter between one of the lines and the corresponding connector in the amplifier and drive it at full power - 20 to 30 volt difference and drop between wall receptacle and power switch inside the amplifier!. I have 3 dozen Cerwin Vega CV-5000 amplifiers rated for 5,000 watts each. They came with 20 amp IEC's - i could not get the amplifiers to put out anything past 2,925 watts bridged at 4 ohms. When I hardwired 8 guage power cords into each of them - 6,600 watts bridged at 4 ohms, pulling 60 amps peak each amplifier.
I’ve been really curious about this topic lately. I picked up a QSC gx5 and a pair of crown k2s this summer which are both rated at 500 watts per channel at an 8ohm load. I’m using the gx5 primarily for my Yamaha club s115 tops and one crown k2 for a pair EAW jf260 tops and the other in bridge mono for EAW two sb180 subs in parallel. I’ve been wondering what the main difference is between these new and old amps are and look forward to continuing this journey with you!
I'm impressed with the QSC GX5. I run the Yamaha club S215 tops off it @4 ohms RMS @1000 watts. It has no problems whatsoever. Other amps supposedly rated much higher seemed to struggle in comparison.
@@stuungar3390 I have a small rack of the GX7 amps (4 of them) for monitors and mains. Love them. Oddly, I prefer separate amps and cabinets more than active boxes. Maybe so I don’t have to lift the amp over my head for a small show with boxes on sticks? They sound good to me and seem to put out a good amount of power. This is a great video!
@@dale116dot7 - would love to get my grubby little mits on a pair of GX7s, they'd be even better then the GX5s. My Subs are separate, so to prevent comb filtering, I run an amp per side (left, right) with 1 channel to sub and other to tops, so no need for Xover 🙂 Ye totally get why you're into passives. Yep, Dave Rat has a truly brilliant channel, sound engineer's porn.
Must be 30 years ago, Sound on Sound did a amp test under real world conditions feeding speakers and with resistors, tapped off the amp's output, fed it up the hall to a second room, and into a small reference amp and speakers. Then listened to the reference system only. This allowed them to match gain between amps, and keep the reference listening level constant with the test amp at 1W or 200W. They must have A/B compared to the source as well. I look forward to hearing your discoveries.
Would you typically recommend using the amplifier the manufacturer recommends from their own brand before researching an amp that may be more dynamic and clear like you’re describing?
Using the recommended amp and processing has huge advantages. My take is rather than buy a system and then try and modify to hot rod it, you are better off buying a better system that does not need the modification. With high end gear like L-Acoustics or d&b or similar, making changes devalues the rental rates devalues the desirability On lower end or especially older gear, upgrading to modern drivers and better amps can pump new life into a system if done properly.
I don’t know if it’s related to your view counts dropping, but the join option for your channel is missing on all of my iOS devices. Shows fine on Android. I wouldn’t think this would cause notification issues tbh, but good luck notifying peeps about their lack of notifications with more notifications.
Oh Dave... Please help are you familiar with turbosound tsw-218 boxes? The guy I bought them from PAINTED THE WIRING ONE SOLID COLOR .. Any good way to test polarity on each side of the box? Maybe a dumb question.. 🤷
The size of the voltage rails and how much and how quickly they can swing is very important. The “new” QSC amps have large voltage rails and their FAST power supply technology that does some cool things including the ability to parallel amplifier channels not just bridge them.
Bought a few cheap pcb amps recently. As a 90's child it was almost commical seeing a 300w rated amp..(thats actually 20 watts constant, if that in reality)
Hey Dave. So I got an amp question for ya. I have a pair of Danley full range passive boxes rated 4 ohm. Boxes are rated 1k cont, 4k peak. I have the choice of powering them with either a Chevin A6000 or a QSC Powerlite 6.0II. Both amps are comparable in power obviously the Chevin has better distortion specs. I’m leaning Chevin, but what do you think?
With continuos signals it is linear but music has like a 5 to 1 or 10 to 1 peak to average ratio. The amp can store energy and supply the peaks. So for music, a 1000 watt amp may be supplying 100 watts average with 1000 watt peaks and drawing 130 watts average from the wall with 200 watt peak draw. Plus to make it more interesting, a 15A circuit breaker will allow park current draws that double or more for short periods of time and tries to allow a 15A average. This is why amps have usable wattage ratings that far exceed the wattage of the power supplying the amp
Ideally specced modern amp also distorts differently, and faster. It is more gradual slope in old amps once you do go over the limits whereas modern amp will go to high distortion very soon. 120W continuous from a 100W modern amp can sound absolutely awful, where with old tech you don't notice anything yet but you can measure it. The price to pay for that is inefficiency, it will draw more power all the time. If the specs are true and properly measured they are real limits these days, when in the past it was more or less a guideline. I've used 1.5x rating in the past, but it should probably be 2x now (have two times more power in the amps than you need)
There is a specification that is often overlooked and that’s the power supply. In my opinion, the majority of amp specifications come from the abilities of the power supply. As you go from an A, A/B, etc amp, the power supplies are different. I’ve used a lot of Crown Macro Tech amps in my day and the power switching capabilities of these amps are quite astounding in my opinion. Also consider my usage of small live gigs for around 500 people. My old Marantz 2250 home stereo with 75 watts/ch blows the doors off my newer NAD stereo that said to be 150 watts/ch. a quick look inside and you’ll find completely different power supplies. Another issue is the quality of your electrical service. Under high demand are you still getting the power required to produce the amps specified power ratings…….??
Testing so far is showing modern supplies are able to deliver high currents very fast and reach higher wattage levels and are free from power supply ripple being audible in the distortions. But they struggle with higher frequencies and have some hf noise on the outputs.
the 'how quickly it can deliver the power' is slew rate, am i correct? Volts per fraction of a second. Its specced for just about every piece of amplifier silicon but i dont think ive ever seen it specced for a power amp system. In terms of the sustained power handling it would be really cool to monitor the B+/- lines of the power supply, just at the transient caps would probably be ideal, for how quickly supply collapses when its hit with large loads, this (effectively the power supply impedance vs capacitance) will be what determines a lot of the power collapse, and often noise on a prolonged large signal i believe. Wish i could join ur paid crew but being a disabled pensioner i am really trying not to enable youtube payment or patreon etc cos i feel like it will be a bottomless pit i cant afford, but i appreciate your content. ty
Yes, slew rate but perhaps more than that. A high slew rate will enable an amp to put out a high frequency at max power. As higher freq and more volt swing both require a higher slew. Damping factor or the ability to stop the speaker moving is important. Also I feel like, and tests would be important, that some amps try to deliver the full voltage and current quickly while others deliver start delivering the the voltage but have limitations in delivering the full current so the voltage ramps up late at higher volumes
I'd be curious to hear your thoughts on Meyer's M Noise as a test signal for measuring system headroom? The idea being that the crest factor of the signal more closely resembles typical program material while providing a standardised test signal.
It's a great idea. More useful than pure pink. Not as useful as doing pink, pulse and tone sweep tests, but less time consuming. I support the concept!
Hi Dave . I have an old Carvin HT760M 750 watt amplifier . I I think I had for years and wanted to use with a Behringer Xenyx 802 for small gigs. But it sounds like crap . I tested the cables and mixer all good the amp seems like the issue . It has buttons on the back Parallel / Limiter / Ground /Lift and a recessed one for bridge . Any advice to dial it in ? Thanks
Hmmm, at medium volumes below clip, none of those switches should make an amp sound bad. It's either the speaker, something else in the chain or just a bad sounding amp
@@DaveRat Thanks . Yeah I checked down line the and it comes back to the amp . Is something like that repairable ? Or not worth it? Thanks again love your channel
Very interesting...I know I am being totally subjective, but I like my older amp sounds using almost any speakers more than the newer models. They try to make speakers that react more efficiently to the "new' class D amps, and maybe they are successful...I have no clue, because I am just a listener and not very knowledgeable about the technicalities.
First time on your channel and I like your approach on this subject but I heard no mention of the most important thing when it comes to audio amplifiers and that's their "REAL" purpose, amplification in dB. For me it's more of an important topic than raw power that an amp can handle. Example: It's much more realistic to say a 60w amp has around 20dB amplification capability,that tells you it's potential to amplify sound. With a proper setup you can make a 100w amp play louder than 1000w amp with a bad setup < low sensitivity speakers, bad cables etc.> I know watts are important and easier to understand but that's why they're more misleading. If you haven't touched this subject there's an idea for another video...
Hamp sensitivity is definitely important. With many modern pro amps the sensitivity is selectable either by switch or software. Since a low sensitivity amp can be configured to reach full output by using a good preamplifier I see that as kind of a separate subject. I did do a video or two on gain structure which maybe more applicable to this
9:08 this doesn't sound right to me, surely if you are putting it down to 2 ohms thats MORE load, not 'half' (Putting two 4 ohm speakers in parallel gives 2 ohms) therefore it can use more of its potentially available power, like saying driving a tractor up a big hill rather than on the flat. it might then be able to use all its horsepower. I agree with everything else you say btw.
I like many forms and types of speakers. Cool designs. From a sound eng standpoint, systems that claim to be point source (no system is actually or event trying to be a frwal point source) I find them more useful for non portable installations and prerecorded music. Bands tend to be very dynamic. Needimg compression when plified for large spaces. Using highly dynamic sound systems makes things more challenging. Also for large spaces, vertical arrays are beneficial I wrote an article a while back called zoned summed and lined that may be interesting
Thanks Dave. I was told that you would need ten times the power to double the volume. Is this true? I really like my old A/B International power amps. Clean with tons of headroom.
@@johnmorreale678 So, if you went from 100 watts to 1000 watts, you would only gain 3db? That’s interesting and I could believe it. I used to biamp a pair of JBL Cabaret 4699b’s. The the 18 inch drivers got their own A/B International bridged, two channel 900 watt power amp. I then split the third A/B 900A for the mids and highs. It was a beast of a stereo. My neighbors hated me. 😁
Yes, hearing is logarithmic, hence the dB scale. Every 10db is double the perceived volume, but 10x the delivered power, so 30dB gain would sound 6x louder, but require 1000x the power
I miss My old crest amps. I don’t miss the weight of the racks which is why I changed them out for modern amps - but I still swear the crest’s had a better dynamic range and just overall better sounding….
@@DaveRat I remember when fp6400’s were ‘the thing to have’ but a lot of guys kept the older crown 5002’s on sub duties- Slew rate was the main factor. From my ‘own’ understanding of reading on different amp topologies - I am still of the mindset that class H offers the best balance of feature/weight/sound/amp topology - and best efficiency per kg vs audio quality. But the market says otherwise.
What I am seeing so far is that high quality newer amps are very good at delivering clean, fast power more efficiently and don't sound as good distorting, delivering hf over 20k and have a lot of fan noise
I`m still a die-hard fan of the BGW 750B`s and Phase Linear 700`s of the `70s. While their power ratings pale in comparison to modern class D amplifiers, the torque the old linear power supply amps deliver just cant be matched by some of the modern amps whose power ratings are many times higher.
Please man this is something i have always wondered cause a few months ago i learned that a Graphics card in a pc running max fan speeds at all times to stay cool let's it boost all the time meaning i get up to 20fps more in gaming titles when underload and ever since then i have wondered if the same can carry over to amps cause in the end equipment runs better when cool but ofcourse there is many variables as you stated but the point stays this is why i like amps with a better damping factor cause it gives me an indicator on wether it will hold power for longer and better or not but this is not a fool proof way of choosing an amp.
Thanks Dave, I will love to see the powersoft video but before that my question is how doo I know the exact speaker impedance, ohms an wattage is this are not written on the speakers or with wrong information?
Usually measuring the DC resistance of 5 or 6 ohms means an 8 ohm driver. 2 to 3 ohms is a 4 ohm driver. And 10 to 13 ohms is a 16 ohm. As far as power handling, need to find the spec or be prepared for some destructive testing
Love your videos Dave, would be interested for you to explain the nitty gritty of speaker impedance and the fact it's not constant (changes with frequency) as this plays heavily into the topic of amplifier power capability, power transferred from amp to speaker is very much dependant on the impedance of the load.
The complete spec should be: X - Watts at 8 ohms 20 to 20k at less than .5% Total Harmonic Distortion. Without all those specs it's tough to compare! RMS!!
I wish it was that easy. Over what time frame? 100ms? 500ms? A minute? An hour? A day? What matters? Do we need continuous full power for music that typically has an excess of 10db peak to average and rarely if ever has peaks that exceed 200ms in time? If an amp puts out 100 watts RMS continuous indefinitely, 250 watts RMS for up to 2 hours at a ventilated room temp of 70 degrees, and 1000 watts for 500 ms and 2000 watts for 100 Ms, all at .1 THD, what do we rate it at? Which poer rating is most correct? Most useful? And which is the best indication of the real world percieved loudness of the music? All of the answers are different. The reality is that an amp that has 500 watts continuos and also 500 watts peak capabilities will not sound near as loud or be as loud with music as an amp that is 125 watts continuos and 2000 watts peak. Fun stuff!
@@DaveRat Hi Dave.Thanks for your comment. I am an "old" Hi-fi geek from the days of McIntosh / Marantz / Crown. / Phase Linear etc and when Grateful Dead chose Mac 3500's to drive their world... TUBE type.. Yes I know they had a truck full of spares too LOL .. A time when PEAK power was used by Marketing to enhance the specs of their equipment with no regard for quality of sound ... 100000 watts at 1ohn with 20% DISTORTION... was fine!....S0 the Power @ 8ohm, 20-20K, THD spec was a way to fine a common denominator amongst vendors... That said I agree.. Peak for a Time or Even RMS power over a time period is an important spec as well, as long as manufacturers are adhering to a similar set of parameters for specifications.. Frankly I think even the OLD School spec Power/Ohms/Frequency/THD has been lost in the milieu of CRAP being sold ..... SO.. I am very interested in the the experiments you are going to conduct, so much so, i "joined" your channel. Now I readily admit I have not worked with the size of system you have, but the principles are the same... good thing OHM's law is rather constant..... LOL ... I have thoroughly enjoyed your Desk comparisons, your mic teardown and builds and your philosophy on Major sound systems... Very old school applied to new technology. it still amazes me that transducers are still the weakest link in the chain. Converting air pressure to electricity or electricity to air pressure is still the holy grail.... Looking forward to your amp tests.... ALSO I love your involvement of "Sammy" your daughter...nice father / daughter relationship
Super cool and great to meet you Sam And agreed and frustrated by misleading specs. I remember that as well. What you describe is what inspired many of the amp tests!
Back in 80 s in the UK you had to cheapo audio system s that would claim instantaneous peak per channel summed at 10% THD. Then came NAD Watts. A very different thing.
@@DaveRat It was a term me and my mates kind of invented . When the NAD 3020b landed in our orbit it was only 20W but my god compared to the 100W and 200W home systems of the time it was night and day more powerful more controlled and just better
This will be a good one! So... New Watts vs Old Watts? Or, perhaps; New 𝙍𝙖𝙩𝙚𝙙 Watts vs Old 𝙍𝙖𝙩𝙚𝙙 Watts ??? Pirates; "𝘞𝘦 𝘸𝘢𝘯𝘵 𝘵𝘩𝘦 𝘟 𝘢𝘹𝘪𝘴" So cool you're going to explore down this rabbit hole, far too many liberties are taken with amp output ratings. It'd be cool to see wattage rating profile... via a suite of measurements. Most importantly measurements that incorporate time. Yes, use the X axis instead of simply the Y axis. Hell yeah, the X axis the honesty axis;) Absolutely offer an all out burst rating, but also include what's sustainable over brief, musically significant periods. Then of course a torturous long term rating which essentially is a throughput capability (not just caps providing for bursts), from the circuit breaker all the way to the load. Also, down this rabbit hole path perhaps some myths can be addressed. Far too much mythology in that "No amplifier can output more than 2400w"... (120v 20a). However breakers can pass massive amounts of current past their rating. To avoid nuisance tripping, a 20a circuit can pass 7-8 times the rated 20a trip amount, that's for about a second or a bit more. It'll pass up to 3x for up to 10sec or so. Amazingly the 20a circuit, can allow up to 1.5x-2x the rated amount for as long as 30 seconds. 100amps for around 1-2 secs 60amps for around 10 secs 30-40amps for up to 30 secs These numbers a big time impactful to high power amplifiers in both pro audio rigs, and HQ home hifi, studio/mastering systems, etc. Implications? Upsize your feeds, avoid voltage drop choke-points. In other words; Build the church for Easter Sunday.
I have a pair of old early 90s peavey amps, cs800x & cs1000x pushing a small bag end speaker system for my synths/euro stuff. I love them but my rolling mixer rack weighs as much as an elephant😂 anyone have any budget friendly recommendations on a lighter pair of amps? Subs are 800w and tops are 600w...
He should be able to replace both of those amps with a single rack space for channel amp that is way more powerful and offers full processing. I don't know the lower line lower cost amps very well but finding something similar to a t904 power soft would be cool
seems like when you listen to home audio stuff, a McIntosh amplifer that is rated at 300W per channel is a lot louder and clearer than a Sony or other consumer brand rated at 500W or more..
Like a light bulb. Calling it a 60 watt light build just defines how my power it consumes. You can get the same amount of lumens with a 15 watt LED. Watts are irrelevant until the utility bill comes. And there is a big difference in the decibels from a 100 watt solid state guitar amp and a 100 watt tube amp. I have a 50 watt Marshall tube and that is much louder that my 100 watt Peavey solid state amp.
@@DaveRatThe The macro tech's distorted when pushed, it was a fabulous thing, if you can find one, stick it on the meter buddy, it would be greatly appreciated, kindest regards from Glasgow Scotland.
@@DaveRat I'll look forward to that, I think I still have 8 or 10 of them lying around in my workshop some where, they're really heavy beasts, bulletproof, reliable old amps, they were everywhere back in the day
I have thoroughly enjoyed Dave Rat university this past year.
It’s been a sound education for us all.
Thank you Whit!
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This is a really good topic. I can add one thing they may help clarify the issue. There's no standard that manufacturers have to use to measure an amps power. Each manufacturer does it their own way. That's why you can go to Walmart and get a 1000 watt home theater in a box for $99. The reality is, if you took 5 amps all rated for the same power, like 100 watts into 8 ohms, every one will measure differently if you did them all the same way. Its been a problem in the industry for years.
Agreed and thank you
I was conversing with a soundman friend about this very topic today - most timely, Dave! We talked about how the digital guitar processor, recorded into software, processed by plugins, played back through a digital mixer into digital amps is "removing the heavy cream, then the light cream, then the 4% milkfat, then 2%, and we're left with nonfat milk" in sound reproduction. I just missed an auction for a Crown MacroTech 5002 Anniversary Edition with a copper faceplate that sold for $1700. Crown only made 200 of them. Of course, then I'd need to buy some passive JBL's (again) to go with it. We're looking forward to this series, Dave, thank you very much for your great dives into our beloved passion.
Awesome, yes, without clear ways to measure and show the value of something, it is easily lost to cheaper, faster and easier..
So true, I used to demo for people a 30 Watt per channel stereo amplifier and showed it put out more clean sound than a cheaper 250 Watt amplifier. The the 30 Watt amplifier was rated into 4 ohms both channels driven at less than 0.1% THD. Clean 60 Watts RMS in a store is quite loud. The 250 watt amp on the other hand was listed a total peak power with no mention of distortion level. On an oxcilioscope, the 30 watt amp put out a little over twice the voltage non-clipped than the 250 Watt amp, or 6DB more clean power out of the speaker. RMS watts specified into a restive load and at a specified distortion level and sine wave is the way to compare apples to apples. In the repair shop, used to torture test amplifiers by running them at their rated power into a dummy load. Not all amps survived. Those that did were stocked. Those that failed to perform to spec were returned. An amp that will do peak un-distorted power for 15 minutes is a good amp.
The numbers that interested me most are not published. How many volts peak to peak does the amp clip into 8 ohms, 4 ohms, 2 ohms, and one ohm if applicable. Can it sustain the peak value for a long time? I used to measure this. Double the voltage = twice the voltage at twice the current into a fixed load or 6 DB more power.EG a 50 volt signal is 6 DB less than a 100 Volt signal. This is the difference between a 100 Watt amp and a 400 Watt amp.
Very cool!
Finally! Glad you shared a version for the public.
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Also immensely grateful for Dave Rat University. Thanks for the heads-up about the notifs!
Thank you Thor!
I’m so glad I found this video. I’ve been putting my old stereo system back in play but and so far I’ve back off a couple amps because I don’t want to blow my speakers or mess up my system. I definitely need 1000 watts even if I need new speakers lets go😂
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Love your videos Dave. Thank you for everything you do and God bless.
Thank you Amar!
Hey Dave it's great your going to have a deep dive into this topic, what makes it more interesting is how there are similar issues and confusion with regard to how the loudspeakers are dealing with the power fed to them, I'm guessing that we will learn quite a bit about that too along the way. Think I'm gonna need some popcorn ; )
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Dave, really love learning from you - and thanks for the sub test at the end of the video, that was awesome!
Awesome and thank you!
I definitely wanna see the powersoft results. But this sounds like an awsome test. Cant wait for these next few videos!
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I didn't know Einstein had a brother? Dave is Great. Watched all videos ! Learned a LOT !!!
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Great stuff, Dave. I will make you smile. Back in the early 80's.... Hill DX700 running 2 ohm per channel into 4 Gauss 4560's and 4 JBL K120 . Incredible amp. 😊😊
Those hill amps were cool. One of the first to employ internal crossovers, ultra compact and drive low impedance loads. Hill deserves more credit for being cutting edge than they get.
Thank you so much Dave! Love your videos. So pragmatic and yet so warm, they are really inspiring! Learned A LOT just by watching them!
Thank you!!!
One other thing that changed is Slew rates, I've been updating the IC's in my Urei 527's to modern IC's for faster slew rates. In terms of those older amps with big heavy transformers versus the modern stuff with lightweight torodials I never considered how long they could put out RMS very awesome video as always!
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Thanks for sharing your experience Dave.
Thank you David!!
Dave rat is an American hero, specializing in audio. A paramount definition of mad scientist. Cant get enough of this guy, I would watch an 8 hour video of him exploring something as bland as e-tape vs gaff tape because he would make it fascinating, he should really start his own school, it would bankrupt fullsail and ultimately exponentially progress the industry via its graduates
Thank you Timothy! Honored!
I'm a bit of a sucker for Crest Audio amps, So I'm extremely intrigued as to what the results are. I've had a lot of experience with their CA series and have always been pleased with the results, especially when driving subs.
Doing more tests now on the Crest
Would love to see an old EV P series amp tested, P3000/CP3000.
Oooh, that will be tough. Will do a few older amps and then focus on modern
Ultimate master SENSEI thanks for all of your time you have taken to make these videos. Super appreciated
Awesome and hell yes! The supersubs emoji! I made myself awesome to see!
@@DaveRat yes of coarse you built it yourself. Man of many talents I swear to you this is my favorite emoji on the planet Earth trying to imagine a stack like that of supersubs. Wouod that cause an earthquake? Omg...
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Glad to see these topics brought up. Pat Brown and has worked a lot to develop a standard way of evaluating amplifiers and speaker ratings. See Common Amplifier Format (CAF). Then you have the rabbit hole of loudspeaker 'power' ratings. In reality the term 'power' is not the best term. In reality we care about how much voltage an amplifier can deliver and over what time frame (yes totally on board with the limitation of many modern designs to deliver full voltage for less than a second); and for many uses that is fine. But sometimes you need an amp that delivers full power for a second or two. Also getting people to understand that with most music (or voice) the real power draw on an amp is going to be at 1/4 to 1/3 the stated power rating is a challenge (when in use at at full volume). Good info. You have worked through this in the trenches.
Yeah, knowing the differences can help select the right tool for the job
@@DaveRat two areas that I have seen modern digital amps perform as lees than expected is with EDM where there is a bass 'drop' with a sine wave component , and artificial reverb, the crest factor of reverberation is about as low as peaked clip noise. Crest factor is a whole 'nother rabbit hole. ;-)
I have the LA12X on the bench and it does not perform as one would expect a class D to perform.
So excited to watch the next episode…thanks for sharing Mr. Rat.
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Love this content. The breakdowns and examples are super helpful for a layman trying to learn.
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I have an early 70’s Acoustic bass amp that’s “only “ 300 ish watts 😎 it’ll flap your trousers at 5 meters away through Ampeg cab and the amp almost vibrates itself off the top 👍🏻
I’ve also got a Bugera Nuke that’s supposed to be powerful and there is no comparison, the old amp blows it away completely:-) and it has more character 👍🏻
It's all about using the right tool for the job. I like the old amps and also a good class D app can really light up a system when you transition from the older amps
I would be interested to see how an LA12X performs in this test
I've got one on the bench to test!
What a cool dude you are , always a fresh look at things that really matter Cheers
Thank you Dave!
I guess the question also is, if you do one amp for the whole frequency spectrum versus splitting spectrum. Love to see more on this!
Interesting. Will see what shows up in tests. Typically gear tends to be defined by its ability to deal with the extremes. I would love to see audio gear able to handle a full octave above and below the intended usage. So gear that can do 10 to 40k will be more than fine for 20 to 20. Narrowing the freq range tends to make the job easier on the gear.
It is always a pleasure to here your analogies and thought processes, so on this point, would you tend to have a set ratio of amp wattage, say 50% of overall power to bass, 30% for mids, and 20% for HF? I ask as I am trying to build 2 small audio systems of 2-way and 4-way active speakers.@@DaveRat
Depends on your crossover points and how many octaves are being powered by each band. Also you can get away with a lot more compression/limiting on low frequencies without being audible then you can on the highs for protection. So for the highs you want extra voltage swing to maintain transients.
Currently the industry standard is to have the same amp for all the bands. Modern amps Will share the power supply energy. Using a four-channel amp with a 15 on channel 1 and another 15 on channel 2 and 4 x 6" on channel 3 and three 2-in on channel 4 is how the K1 is powered. Similar power configurations are very common and just using a multi-channel amp the power everything is easy and kind of a cool way to go
Ah yes, the transients, it makes sense now you mention it, Thank you.@@DaveRat
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Look forward to the amp test!!!
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As always, very informative and thought provoking video. Thanks for taking the time out of your busy schedule to further educate us on live sound.
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Thanks for the video. Recently I bought an old amp at auction to fool around with and i was wondering if you could help shed some light on it.
Its about 18 years old and made in Australia by a now-defunct company called MSR. There's no manual and details about it are slim.
What I do know is on the back it reads "This amplifier produces 850W RMS into 4ohms per channel continuously, 1600WRMS bursts." And on the inside, instead of a handful of large capacitors it has about 30 small ones per channel.
If you don't mind, I've got two questions;
a) what kind of mutant am I dealing with? and
b) could you recommend an appropriate sub driver for small parties?
Cheers
Lots of small caps vs fewer big ones is not an issue. Its the total capacitance that stores some energy to improve output power from sagging. as far as subs. too many options and I think that can be better answered in like a reddit post or an online audio forum where ya share more info and people can assist
Thank you so much for sharing your knowledge, Dave! Much love from Russia.
Thank you Dmitri! And would love to wander your way and hang out someday!
Thank you 👍
I am using old EV P3000’s can’t say they are easy to lift,
But I enjoy the headroom
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I had to take out the IEC power connectors and hardwired cords of the proper guage into all my amplifiers. I haven't had an amplifier failure since then. The IEC power connectors are THE number one cause of amplifier failures as they are only meant to carry 10 amps. The 20 amp IEC only carries 15 amps. The power lights don't dim on my amplifiers any more. If you don't believe me, put a volt meter between one of the lines and the corresponding connector in the amplifier and drive it at full power - 20 to 30 volt difference and drop between wall receptacle and power switch inside the amplifier!. I have 3 dozen Cerwin Vega CV-5000 amplifiers rated for 5,000 watts each. They came with 20 amp IEC's - i could not get the amplifiers to put out anything past 2,925 watts bridged at 4 ohms. When I hardwired 8 guage power cords into each of them - 6,600 watts bridged at 4 ohms, pulling 60 amps peak each amplifier.
This will be super interesting!
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Great video Brother Dave, you are a badass!
👍 thank you Mark!
Hi Dave , Im from Panama in central america , I learned a lot with your videos , thanks for share your knowledge.
Thank you Cesar!
I’ve been really curious about this topic lately. I picked up a QSC gx5 and a pair of crown k2s this summer which are both rated at 500 watts per channel at an 8ohm load. I’m using the gx5 primarily for my Yamaha club s115 tops and one crown k2 for a pair EAW jf260 tops and the other in bridge mono for EAW two sb180 subs in parallel. I’ve been wondering what the main difference is between these new and old amps are and look forward to continuing this journey with you!
I'm impressed with the QSC GX5.
I run the Yamaha club S215 tops off it @4 ohms RMS @1000 watts. It has no problems whatsoever. Other amps supposedly rated much higher seemed to struggle in comparison.
@@stuungar3390 I have a small rack of the GX7 amps (4 of them) for monitors and mains. Love them. Oddly, I prefer separate amps and cabinets more than active boxes. Maybe so I don’t have to lift the amp over my head for a small show with boxes on sticks? They sound good to me and seem to put out a good amount of power. This is a great video!
@@dale116dot7 - would love to get my grubby little mits on a pair of GX7s, they'd be even better then the GX5s. My Subs are separate, so to prevent comb filtering, I run an amp per side (left, right) with 1 channel to sub and other to tops, so no need for Xover 🙂
Ye totally get why you're into passives.
Yep, Dave Rat has a truly brilliant channel, sound engineer's porn.
Excellent I will test more amps soon!
Very interesting, as always with your videos.
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Dave muchas gracias por compartir tu conocimiento y experiencia, saludos
Must be 30 years ago, Sound on Sound did a amp test under real world conditions feeding speakers and with resistors, tapped off the amp's output, fed it up the hall to a second room, and into a small reference amp and speakers. Then listened to the reference system only. This allowed them to match gain between amps, and keep the reference listening level constant with the test amp at 1W or 200W. They must have A/B compared to the source as well. I look forward to hearing your discoveries.
Love these tests!
Would you typically recommend using the amplifier the manufacturer recommends from their own brand before researching an amp that may be more dynamic and clear like you’re describing?
Using the recommended amp and processing has huge advantages. My take is rather than buy a system and then try and modify to hot rod it, you are better off buying a better system that does not need the modification.
With high end gear like L-Acoustics or d&b or similar, making changes devalues the rental rates devalues the desirability
On lower end or especially older gear, upgrading to modern drivers and better amps can pump new life into a system if done properly.
Nice shirt, If you are from the area you know that place. I love their business signs and that they change it weekly.
Yes! Great store!
Your content is fantastic.
Thank you Rons!
I don’t know if it’s related to your view counts dropping, but the join option for your channel is missing on all of my iOS devices. Shows fine on Android. I wouldn’t think this would cause notification issues tbh, but good luck notifying peeps about their lack of notifications with more notifications.
Thank you, helpful!
It would be great to see the power delivery duration between a Powersoft X4 & a Lab.Gruppen PLM12K44!! Looking forward to more of these videos Dave.
I have an X4 on the bench and started testing yesterday
@@DaveRat Amazing. I've got a PLM+ but no oscilloscope.
Oh Dave... Please help are you familiar with turbosound tsw-218 boxes? The guy I bought them from PAINTED THE WIRING ONE SOLID COLOR .. Any good way to test polarity on each side of the box? Maybe a dumb question.. 🤷
Thank you
Hey hey Matty! Yes, use a 9volt battery. Speakers will move outward when the plus of the battery in on the plus wire of the speaker
@@DaveRat k great thank u.. Easy enough
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oohhh watt is this video going to be about I wonder!
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Will be brilliant, can't wait 🙂
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The size of the voltage rails and how much and how quickly they can swing is very important. The “new” QSC amps have large voltage rails and their FAST power supply technology that does some cool things including the ability to parallel amplifier channels not just bridge them.
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Bought a few cheap pcb amps recently. As a 90's child it was almost commical seeing a 300w rated amp..(thats actually 20 watts constant, if that in reality)
Hey Dave. So I got an amp question for ya. I have a pair of Danley full range passive boxes rated 4 ohm. Boxes are rated 1k cont, 4k peak. I have the choice of powering them with either a Chevin A6000 or a QSC Powerlite 6.0II. Both amps are comparable in power obviously the Chevin has better distortion specs. I’m leaning Chevin, but what do you think?
I would do a test using a pulse up to clip and a/b the diff and see if there is anything audible
I'm also interested in the amount of AC current the amp draws vs watts it puts out. Is it a linear relationship or not at all?
With continuos signals it is linear but music has like a 5 to 1 or 10 to 1 peak to average ratio. The amp can store energy and supply the peaks. So for music, a 1000 watt amp may be supplying 100 watts average with 1000 watt peaks and drawing 130 watts average from the wall with 200 watt peak draw.
Plus to make it more interesting, a 15A circuit breaker will allow park current draws that double or more for short periods of time and tries to allow a 15A average.
This is why amps have usable wattage ratings that far exceed the wattage of the power supplying the amp
Finally!!! A objective amp test!!
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I really want to know if a SMPS amp deliver better then a transformer amp..
Hmmm, "better" is a tough one. Definitely different. And will be fun to test
This series should be good.
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Ideally specced modern amp also distorts differently, and faster. It is more gradual slope in old amps once you do go over the limits whereas modern amp will go to high distortion very soon. 120W continuous from a 100W modern amp can sound absolutely awful, where with old tech you don't notice anything yet but you can measure it. The price to pay for that is inefficiency, it will draw more power all the time. If the specs are true and properly measured they are real limits these days, when in the past it was more or less a guideline. I've used 1.5x rating in the past, but it should probably be 2x now (have two times more power in the amps than you need)
I figured out a cool way to test and hear the distortion. Doing new vids on it now
BEEN WAITING< AWSOME
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There is a specification that is often overlooked and that’s the power supply. In my opinion, the majority of amp specifications come from the abilities of the power supply. As you go from an A, A/B, etc amp, the power supplies are different. I’ve used a lot of Crown Macro Tech amps in my day and the power switching capabilities of these amps are quite astounding in my opinion. Also consider my usage of small live gigs for around 500 people. My old Marantz 2250 home stereo with 75 watts/ch blows the doors off my newer NAD stereo that said to be 150 watts/ch. a quick look inside and you’ll find completely different power supplies. Another issue is the quality of your electrical service. Under high demand are you still getting the power required to produce the amps specified power ratings…….??
Testing so far is showing modern supplies are able to deliver high currents very fast and reach higher wattage levels and are free from power supply ripple being audible in the distortions. But they struggle with higher frequencies and have some hf noise on the outputs.
the 'how quickly it can deliver the power' is slew rate, am i correct? Volts per fraction of a second. Its specced for just about every piece of amplifier silicon but i dont think ive ever seen it specced for a power amp system.
In terms of the sustained power handling it would be really cool to monitor the B+/- lines of the power supply, just at the transient caps would probably be ideal, for how quickly supply collapses when its hit with large loads, this (effectively the power supply impedance vs capacitance) will be what determines a lot of the power collapse, and often noise on a prolonged large signal i believe.
Wish i could join ur paid crew but being a disabled pensioner i am really trying not to enable youtube payment or patreon etc cos i feel like it will be a bottomless pit i cant afford, but i appreciate your content. ty
Yes, slew rate but perhaps more than that. A high slew rate will enable an amp to put out a high frequency at max power. As higher freq and more volt swing both require a higher slew.
Damping factor or the ability to stop the speaker moving is important. Also I feel like, and tests would be important, that some amps try to deliver the full voltage and current quickly while others deliver start delivering the the voltage but have limitations in delivering the full current so the voltage ramps up late at higher volumes
I'd be curious to hear your thoughts on Meyer's M Noise as a test signal for measuring system headroom? The idea being that the crest factor of the signal more closely resembles typical program material while providing a standardised test signal.
It's a great idea. More useful than pure pink. Not as useful as doing pink, pulse and tone sweep tests, but less time consuming. I support the concept!
Hi Dave . I have an old Carvin HT760M 750 watt amplifier . I I think I had for years and wanted to use with a Behringer Xenyx 802 for small gigs. But it sounds like crap . I tested the cables and mixer all good the amp seems like the issue . It has buttons on the back Parallel / Limiter / Ground /Lift and a recessed one for bridge . Any advice to dial it in ? Thanks
Hmmm, at medium volumes below clip, none of those switches should make an amp sound bad. It's either the speaker, something else in the chain or just a bad sounding amp
@@DaveRat Thanks . Yeah I checked down line the and it comes back to the amp . Is something like that repairable ? Or not worth it? Thanks again love your channel
Very interesting...I know I am being totally subjective, but I like my older amp sounds using almost any speakers more than the newer models. They try to make speakers that react more efficiently to the "new' class D amps, and maybe they are successful...I have no clue, because I am just a listener and not very knowledgeable about the technicalities.
I like the older amps as well. Less weird complex stuff going on, but also, to get loud and be portable for big shows, new amps are the only way to go
First time on your channel and I like your approach on this subject but I heard no mention of the most important thing when it comes to audio amplifiers and that's their "REAL" purpose, amplification in dB. For me it's more of an important topic than raw power that an amp can handle. Example: It's much more realistic to say a 60w amp has around 20dB amplification capability,that tells you it's potential to amplify sound. With a proper setup you can make a 100w amp play louder than 1000w amp with a bad setup < low sensitivity speakers, bad cables etc.> I know watts are important and easier to understand but that's why they're more misleading. If you haven't touched this subject there's an idea for another video...
Hamp sensitivity is definitely important. With many modern pro amps the sensitivity is selectable either by switch or software. Since a low sensitivity amp can be configured to reach full output by using a good preamplifier I see that as kind of a separate subject.
I did do a video or two on gain structure which maybe more applicable to this
@Dave Rat, Should we buy all the FP6400 there are? Before your video gets out and price will sky rocket?
Hmmm, the labs are cool but some of the newer apps have some assets that are even cooler
9:08 this doesn't sound right to me, surely if you are putting it down to 2 ohms thats MORE load, not 'half' (Putting two 4 ohm speakers in parallel gives 2 ohms) therefore it can use more of its potentially available power, like saying driving a tractor up a big hill rather than on the flat. it might then be able to use all its horsepower. I agree with everything else you say btw.
Yes, I should have said half the impedance or half the ohms
Great video. 😀👍♥️
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Hi have you tried kv2 audio speakers/amps? I wonder what your thoghts on them
I like many forms and types of speakers. Cool designs.
From a sound eng standpoint, systems that claim to be point source (no system is actually or event trying to be a frwal point source) I find them more useful for non portable installations and prerecorded music.
Bands tend to be very dynamic. Needimg compression when plified for large spaces.
Using highly dynamic sound systems makes things more challenging.
Also for large spaces, vertical arrays are beneficial
I wrote an article a while back called zoned summed and lined that may be interesting
@@DaveRatcool, thanks for the fast replay, i'll look it up :)
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Thanks Dave. I was told that you would need ten times the power to double the volume. Is this true? I really like my old A/B International power amps. Clean with tons of headroom.
I think the general rule is that when you double the power you gain 3db. I could be wrong but I remember reading something like that
@@johnmorreale678 So, if you went from 100 watts to 1000 watts, you would only gain 3db? That’s interesting and I could believe it. I used to biamp a pair of JBL Cabaret 4699b’s. The the 18 inch drivers got their own A/B International bridged, two channel 900 watt power amp. I then split the third A/B 900A for the mids and highs. It was a beast of a stereo. My neighbors hated me. 😁
Yes, hearing is logarithmic, hence the dB scale. Every 10db is double the perceived volume, but 10x the delivered power, so 30dB gain would sound 6x louder, but require 1000x the power
Would 30 db not be 8X?
100 wats to 200 watts would be 3db, audibly louderz 100 to 1000 would be 10 db which people say is perceptively twice as loud.
1:50 he’s on it for one and all !
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Watched on my uhd curved samsung TV. 1st video played no problems then it wouldn't play others after.
Interesting, not sure I would know where to begin looking into that but sounds like a CZcams issue or maybe those are links to member vids
I miss My old crest amps.
I don’t miss the weight of the racks which is why I changed them out for modern amps - but I still swear the crest’s had a better dynamic range and just overall better sounding….
Agreed and that same concept is the foundation of the video
@@DaveRat I remember when fp6400’s were ‘the thing to have’ but a lot of guys kept the older crown 5002’s on sub duties-
Slew rate was the main factor.
From my ‘own’ understanding of reading on different amp topologies - I am still of the mindset that class H offers the best balance of feature/weight/sound/amp topology - and best efficiency per kg vs audio quality. But the market says otherwise.
What I am seeing so far is that high quality newer amps are very good at delivering clean, fast power more efficiently and don't sound as good distorting, delivering hf over 20k and have a lot of fan noise
I`m still a die-hard fan of the BGW 750B`s and Phase Linear 700`s of the `70s. While their power ratings pale in comparison to modern class D amplifiers, the torque the old linear power supply amps deliver just cant be matched by some of the modern amps whose power ratings are many times higher.
I would love to figure out a way to measure exactly that
Please man this is something i have always wondered cause a few months ago i learned that a Graphics card in a pc running max fan speeds at all times to stay cool let's it boost all the time meaning i get up to 20fps more in gaming titles when underload and ever since then i have wondered if the same can carry over to amps cause in the end equipment runs better when cool but ofcourse there is many variables as you stated but the point stays this is why i like amps with a better damping factor cause it gives me an indicator on wether it will hold power for longer and better or not but this is not a fool proof way of choosing an amp.
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Thanks Dave, I will love to see the powersoft video but before that my question is how doo I know the exact speaker impedance, ohms an wattage is this are not written on the speakers or with wrong information?
Usually measuring the DC resistance of 5 or 6 ohms means an 8 ohm driver. 2 to 3 ohms is a 4 ohm driver. And 10 to 13 ohms is a 16 ohm.
As far as power handling, need to find the spec or be prepared for some destructive testing
@@DaveRat how doo I get the measurement done, by using multi-meter?
@@DaveRat how doo I get the measurement done, by using multi-meter?
@@DaveRat how doo I get the measurement done, by using multi-meter?
Yes, a multimeter
Any Lab Grupen or Mc2?
Yes, will test a lab 6400
Love your videos Dave, would be interested for you to explain the nitty gritty of speaker impedance and the fact it's not constant (changes with frequency) as this plays heavily into the topic of amplifier power capability, power transferred from amp to speaker is very much dependant on the impedance of the load.
I will add that in to the mix of potential vids
@@DaveRat Awesome, thank you.
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I’m just waiting until you launch Rat University then I’m enrolling.
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Crown DC-300A is my king ;)
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The complete spec should be: X - Watts at 8 ohms 20 to 20k at less than .5% Total Harmonic Distortion. Without all those specs it's tough to compare! RMS!!
I wish it was that easy.
Over what time frame? 100ms? 500ms? A minute? An hour? A day?
What matters? Do we need continuous full power for music that typically has an excess of 10db peak to average and rarely if ever has peaks that exceed 200ms in time?
If an amp puts out 100 watts RMS continuous indefinitely, 250 watts RMS for up to 2 hours at a ventilated room temp of 70 degrees, and 1000 watts for 500 ms and 2000 watts for 100 Ms, all at .1 THD, what do we rate it at?
Which poer rating is most correct? Most useful? And which is the best indication of the real world percieved loudness of the music? All of the answers are different.
The reality is that an amp that has 500 watts continuos and also 500 watts peak capabilities will not sound near as loud or be as loud with music as an amp that is 125 watts continuos and 2000 watts peak.
Fun stuff!
@@DaveRat Hi Dave.Thanks for your comment. I am an "old" Hi-fi geek from the days of McIntosh / Marantz / Crown. / Phase Linear etc and when Grateful Dead chose Mac 3500's to drive their world... TUBE type.. Yes I know they had a truck full of spares too LOL .. A time when PEAK power was used by Marketing to enhance the specs of their equipment with no regard for quality of sound ... 100000 watts at 1ohn with 20% DISTORTION... was fine!....S0 the Power @ 8ohm, 20-20K, THD spec was a way to fine a common denominator amongst vendors... That said I agree.. Peak for a Time or Even RMS power over a time period is an important spec as well, as long as manufacturers are adhering to a similar set of parameters for specifications.. Frankly I think even the OLD School spec Power/Ohms/Frequency/THD has been lost in the milieu of CRAP being sold ..... SO.. I am very interested in the the experiments you are going to conduct, so much so, i "joined" your channel. Now I readily admit I have not worked with the size of system you have, but the principles are the same... good thing OHM's law is rather constant..... LOL ... I have thoroughly enjoyed your Desk comparisons, your mic teardown and builds and your philosophy on Major sound systems... Very old school applied to new technology. it still amazes me that transducers are still the weakest link in the chain. Converting air pressure to electricity or electricity to air pressure is still the holy grail.... Looking forward to your amp tests.... ALSO I love your involvement of "Sammy" your daughter...nice father / daughter relationship
Super cool and great to meet you Sam
And agreed and frustrated by misleading specs. I remember that as well. What you describe is what inspired many of the amp tests!
Awesome!!
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Please do the behringer inukes
Will see, I don't have one though
I'm guessing Behringer's amps have been tested much more than any other amp mfr.
They are cheap. I have one you can use to test. I know they have been tested, but I like Dave's tests way better.
If I get one I will test it.
@@TrainedZombie
It'll def be way cooler, no doubt
Back in 80 s in the UK you had to cheapo audio system s that would claim instantaneous peak per channel summed at 10% THD.
Then came NAD Watts. A very different thing.
Interesting. Would love to see more info on NAD watts and what it stood for. Curious
@@DaveRat It was a term me and my mates kind of invented . When the NAD 3020b landed in our orbit it was only 20W but my god compared to the 100W and 200W home systems of the time it was night and day more powerful more controlled and just better
Very cool and yes, I have read about Nad under rating their amps and how good they are
This will be a good one! So...
New Watts vs Old Watts?
Or, perhaps;
New 𝙍𝙖𝙩𝙚𝙙 Watts
vs Old 𝙍𝙖𝙩𝙚𝙙 Watts ???
Pirates; "𝘞𝘦 𝘸𝘢𝘯𝘵 𝘵𝘩𝘦 𝘟 𝘢𝘹𝘪𝘴"
So cool you're going to explore down this rabbit hole, far too many liberties are taken with amp output ratings.
It'd be cool to see wattage rating profile... via a suite of measurements. Most importantly measurements that incorporate time. Yes, use the X axis instead of simply the Y axis.
Hell yeah, the X axis the honesty axis;)
Absolutely offer an all out burst rating, but also include what's sustainable over brief, musically significant periods.
Then of course a torturous long term rating which essentially is a throughput capability (not just caps providing for bursts), from the circuit breaker all the way to the load.
Also, down this rabbit hole path perhaps some myths can be addressed.
Far too much mythology in that "No amplifier can output more than 2400w"... (120v 20a).
However breakers can pass massive amounts of current past their rating. To avoid nuisance tripping, a 20a circuit can pass 7-8 times the rated 20a trip amount, that's for about a second or a bit more. It'll pass up to 3x for up to 10sec or so.
Amazingly the 20a circuit, can allow up to 1.5x-2x the rated amount for as long as 30 seconds.
100amps for around 1-2 secs
60amps for around 10 secs 30-40amps for up to 30 secs
These numbers a big time impactful to high power amplifiers in both pro audio rigs, and HQ home hifi, studio/mastering systems, etc.
Implications?
Upsize your feeds, avoid voltage drop choke-points.
In other words; Build the church for Easter Sunday.
True, though not only has the ratings changes but also the way many amps deliver power has changed as well.
Have you look into cvr amps compared to the powersoft
I have not
I have a pair of old early 90s peavey amps, cs800x & cs1000x pushing a small bag end speaker system for my synths/euro stuff. I love them but my rolling mixer rack weighs as much as an elephant😂 anyone have any budget friendly recommendations on a lighter pair of amps? Subs are 800w and tops are 600w...
He should be able to replace both of those amps with a single rack space for channel amp that is way more powerful and offers full processing.
I don't know the lower line lower cost amps very well but finding something similar to a t904 power soft would be cool
seems like when you listen to home audio stuff, a McIntosh amplifer that is rated at 300W per channel is a lot louder and clearer than a Sony or other consumer brand rated at 500W or more..
I believe that. Especially with tube amps that can be driven into non linear volume levels and still sound good
Ganahl Lumber rocks
Ha! Yes it does!
Like a light bulb. Calling it a 60 watt light build just defines how my power it consumes. You can get the same amount of lumens with a 15 watt LED. Watts are irrelevant until the utility bill comes. And there is a big difference in the decibels from a 100 watt solid state guitar amp and a 100 watt tube amp. I have a 50 watt Marshall tube and that is much louder that my 100 watt Peavey solid state amp.
Similar yes
Crown 5000 Vz
Heavy and solid but I preferred the Crest 8001 for watts per pound and running low impedances
@@DaveRatThe The macro tech's distorted when pushed, it was a fabulous thing, if you can find one, stick it on the meter buddy, it would be greatly appreciated, kindest regards from Glasgow Scotland.
Love to test one but sold all ours years ago. I will test several amps and hopefully enough to get a solid take
@@DaveRat I'll look forward to that, I think I still have 8 or 10 of them lying around in my workshop some where, they're really heavy beasts, bulletproof, reliable old amps, they were everywhere back in the day
Yeah, I wanted to keep one or two for exactly this reason but the old gear piling up had to be thinned
❤️❤️❤️
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If anybody is going to find new and interesting ways it’s you.
Thank you Steven!
Only 3 dislikes lol holy sht who can get through this lol sorry Dave but jeezus man!
I have no idea what you are trying to convey, but I do have a few people that I am sure follow me to dislike!
whats?
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Let's not forget THD.