Peavey 5150 Troubleshooting and Repair + Bias Mod Tips and Play-through
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- čas přidán 25. 04. 2020
- Repair Blog 002
In this episode I go through a Peavey 5150 that had a few problems. The ribbon cable that carries the heater voltage supply from the main board to the output tube board has burnt the traces on the PCB and must be replaced. To make the repair even more fun I had to go through many different troubleshooting methods to find some hidden cold solder joints left by a previous "tech".
An adjustable bias mod had been installed and I had changed one of the values of parts in order to get the bias into the correct range. I tried my best to detail those steps in this video for those interested in carrying out this modification.
Fast forward to the end to hear the 5150 in action! - Jak na to + styl
Best untitled show on CZcams. You should invite pustulus over for an interview
I've had my 5150 II since 1999 and never had one problem with it...Smokin' Tone...
I love 5150s so much. They're more then a on trick pony, as they do everything from light crunch to insane lead gain really well. Cleans are okay with some modulation and time based effects in the loop.
Dude you can get pristine clean tones. Low rhythm pre gain and high rhythm post gain.
I love Peaveys because they are American made and clean up nicely; in the end you’ve reserected a revered classic.
great repair video, also killer playing!
really liking your delivery of content...
Thank you for a great video. I appreciate all the effort you put in to it!
❤great job me learning.😮
Thanks for posting this. My 5150 is sounding a little thin and anemic. I am planning to open it up. I was initially thinking the pots were old, but I’ll check the tube sockets first.
Dude, you're a monster. Your riffage kicks ass
I dig the videos. At the moment I have an 84 butcher, 6505+, and me and my dad kinda have a shared 5150 1 (kinda a shop head, who ever comes to the band room to jam can play that one) peavey is great, drop one out the back of the truck it only get louder!
Awesome riffage dude, thanks for posting this video, I have built a few handwired amps over the years, but could never figure out my peavey 6505+ fluctuating volume problem. Now I have an Idea where to look for the issue and a possible fix, it seems those damn molex cables should have never been used in these amps or any for that matter, and I can't even begin to describe how I feel about those pcb mounted tube sockets. Thanks again Subscribed
Your Fluctuating volume is likely to be the six wire molex connector connection to the rear mounted Send Return Loop board. Its a very common problem that the wires fray and hang by a thread or two of wire strands.
**** A+ on the effort.
I need you to run through my block letter 5150. You have that thing sounding like the monster it's supposed to be!
I sold my original 5150. The next day Eddie died. I owned it for 25 years. I never had a problem with it. Used it at every gig I ever played and every band practice. Only changed the tubes once in 25 years about 8 years ago. I never liked the sound of the amp on it's own so I used a line 6 Pod 2.0 through the effects loop and every show people would comment on how crushing my sound was.
DAM never sell anything
Awesome video! Can I send my 5150 to you to repair?
I just bought a 5150 ii and these issues are things I worry about, it would amazing to know who could repair it
I forget the reason why Peavey went with such a cold bias for the 5150. You’d think it was likely something to do with headroom, but that wasn’t it, I don’t think. It had something to do with crossover distortion, I believe… and it being something they wanted? Don’t quote me on that though.
I'm glad I found this! Given you've repaired many 5150's and possibly many other amps could tell me what the MOST reliable or robust guitar amplifier would be for rock/metal? I'm starting understand why many guitarists elect a Marshall JCM-800 with a boost; i.e. Single channel + PTP = simple. I know Soldano SLO-100 use a PCB but the amp itself isn't complex and I would think that Soldano SLO-100 amplifiers are that expensive because the components aren't average but top shelf. At least the price would suggest this.
I have had great success with old Marshall's for sure. For rock and metal the 2204/2203 amps will absolutely get the job done. Coupled with an overdrive they can sound beastly. The Soldano amplifiers are very well built and constructed in a way to have less noise. They are also another very good choice for reliability. All amps can break down but keeping them well maintained is the key. I am rocking amps from the 70's that can survive the rugged tour life no problem. Also plenty of great amps are on PCB's. Its all about the design and layout that makes the difference.... Laney GH100L is another very simple and reliable amp.
@@purgasound Thanks for the response. In relation to PCB's I ask because I saw that you ran some solder along the a "signal leg?" on the 5150 to bridge it; seeing that makes me weary of the 5150 but also PCB's in general; however I do understand that PCB quality varies just as PTP does. I used to be 'that' guitarist that always wanted one magic amp to do it all and so always purchased complex amplifiers when in fact I only ever used the drive channel; hence-forth - from that moment of realisation onwards - I changed my criteria when assessing guitar amplifiers. For me; one channel that can reach AC/DC's 'Fly on the Wall' guitar tone without a boost and then to Ratt and Cannibal Corpse with varying degree's of boost. I did hear good things about the Laney GH100-L..and they're affordable. One last question: I do enjoy the tone of the Krank Revolution Plus as it has this incredible mid-range voicing and almost a clean gain much like the Soldano SLO100; I guess that's why some refer to it as the 'poor mans SLO'?! Could you offer a reliability assessment on one if you've worked on it?
@@firststep7750 Poor man's SLO is a Jet City. Literally. JCM 800 is not PTP, Marshall has only produced that circuit with PCB since it's intro in late '75/early '76, can't remember exactly when. As far as reliability goes, well, what are you getting after? Do you want an amp that'll still work after you drop kick it down a flight of stairs? Amps from most major manufacturers are pretty reliable if used as intended and not abused, it is not conceptually hard to build a reliable tube amp after all. Generally speaking though, the more complex, the more chances something can go wrong, and hence maybe less reliable. Note maybe. Also maybe not lol.
Hey great video (5150iier here) are you Pustulus maximus?
Just picked up a very clean 6534+ the other day. Was fine when I tested it out. Finally got to really open it up last night at practice. The harder I strummed or palm muted, I noticed fluctuations in the volume.... Spikes and cuts... Turned the volume knob and would get crackle and poping... Gonna open it up and see what the preamp tubes look like. I will look at the power amp tubes, but they were apparently just changed and maybe have 10 hours on them. Also probably clean the pots with some deoxit.... Anyone ever experience something like I mentioned with a 6505+ or any other amp for that matter?
Mine is doing the same thing I just ordered new tubes. I cleaned my volume pots it seems to help. Did you figure out your issue? I would clean volume pots and tube sockets. I think it does mine so far so good but I still think I get very rare volume drops
Offhand Disney INCOMING
What tubes do you prefer for the 5150 in the power and preamp sections?
You like those G12T-75s huh? 🐴🔥
Actually been digging them a lot more since I've been doing a bunch of demos with them. The mid focused speakers are great too but in a mix there's a lot less in the middle that I need to cut to stay out of the way of the rest of the band.
@@purgasound That's true, I always worry though that in a personal mix its gonna have that effect that its not up front enough to sit on top to hear it, but it sits well within an overall mix or lower in someone else's mix itself. That's why I like the double mic option.
I just got my 5150
I noticed the rhythm and lead is are pretty noises. Is this common or should I service it?
I also notice the lead post gain pot is scratchy.
This an easy fix?
Those 5150s need those ribbon cables removed and wires soldered direct from board to board.
Hi, can you please tell me what kind of pots are there in the post gain/volume of the crunch channel? Mine got broken. Any alternative replacement you can suggest? Thank you.
Did you ever find out?
Dude, did you play a riff from The Mentors? :D
Good ear
Do you bias the amp with the volume off? Because of I play and turn up the volume the bias will also increase from 43 mA to something like 50-60 mA. Shouldn’t you set the bias at the correct volume instead of turned off/low?
Thanks for this video!
I am biasing using formulas based on idle current. This is taking your readings with the amp at idle. When playing at full volume the bias can rise far beyond the readings we take at idle.
@@purgasound thanks for the explanation!
why my 5150 head has a hum sound on the power section? how I can fix this?
Anyone know where I can get the panel behind the grill for either 5150/6505? Can’t find them anywhere. What are they made out of? Wood or?
Wood
i was playing my 1993 peavey 5150 on the channel 3 setting at bedroom level. and all of a sudden there was a big gain drop. there was still volume but the post gain was very off. could it be a power tube or a pre amp tube?
Hard to say. Would need to open it up and look. The 5150 design had many potential points of failure. A common one is the tube heater traces or the quick connect contacts burning up on the power tube board. I would check there first.
@@purgasound i opened it up and everything looks good. no burnt connections or anything out of place. i cleaned out the fx loop jacks and pots with electronics cleaner. is there anything else you would recommend??
Ever seen a "real 3 channel" mod on a 5150 ii/iii or 6505+? Can you perform this? or would you steer people away from this mod?
Just buy a Peavey Ultra or JSX to have a true 3 channel head, with separate EQ'S.
tune the bias to 20-30mA and you will hear perfection sound!!!!
I’ve got a volume drop problem on my 5150 ll. It drops out after about 3-5 minutes it goes quiet. I’ve retubed it , any ideas would be appreciated.
I have an original block letter that had the same problem...... what I did was take the amp apart and re-solder the main PCB, component by component.....Amp sounded better than ever and no more volume drops. It must have been a dry solder joint. If you try this yourself, please be careful..... there's some big capacitors in there!! Good luck
@@derekhalpin8571 how long did it take to get that done ? I don’t think I will do it myself
@@Dicktoben It took me about an hour to do the main PCB. If you're not sure about what you're doing, it's probably best to leave it to an amp repair specialist. Hope you get it sorted, they are great amps when they are working.
My hot 5150 got knocked over after a bar show and no issues I can hear lol
@purgasound How do I get ahold of you to talk about amp servicing?
Brent@purgasound.com
hello i am curious if you are in the Virginia are? i have a KRANKENSTEIN+ head that i would like to have gone over by a professional.
For those considering modding a 5150: Please don't ruin a 5150 with a bias mod. The amp was designed to sound amazing with the stock, cold bias. And it does. You can always add a low pass filter if you want it to sound dark and muddy and ruin it's beautiful sparkling tone.
Having an adjustable bias does not change the amp's sound on its own. Quite the contrary, it would enable a qualified technician to keep the amp sounding consistent when changing output tubes. Since every set of tubes will draw different amounts of current it is helpful to be able to set the bias to fall within the appropriate range. Without the ability to do so a new set of tubes could run substantially hotter or colder than the previous set. Their choice to leave out the adjustment and set the bias cold was based on keeping the amp working through it's warranty period. It wasn't because they wanted it to sound a certain way. I don't suggest anyone run the tubes hot in these anyway as there is no real benefit.
Cheers
@@purgasound EVH ran this amp stock without an adjustable bias and if he didn't like the tone that way he would have never given James Brown a days rest.
@@MichaelDespairs Ok, well I just explained how an adjustable bias can allow different sets of tubes operate within the same parameters and you're telling me that it's better for tone if the amp doesn't sound consistent when swapping tubes. We're going to have to agree to disagree. EVH was an amazing player, not an amp designer or electronics engineer.
The amp was also designed around Sylvania 6L6's that Peavey had in stock and are no longer made.
I had no idea those were built that way. Yuck
Why the fuck don't I live in America? I need people like you to help me with my fucking problematic gear...
And that’s why Peapee amps not only suck, but are cheap and plentiful!
What a horrible design.