Discharging Filter Capacitors & Reading Voltage in your Tube Amp | The Electric Lady
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- čas přidán 29. 06. 2024
- 0:00-0:50 Introduction to Amplifier Safety
0:50-2:50 Explanation of Filter Cap & Different Types
2:50-4:13 How to Measure Voltage
4:13-5:15 See the High Voltage
5:15-End Discharging Filter Cap Demonstration - Jak na to + styl
It's ridiculous how long it took me to find something so clear and informative. Seriously excellent video.
Everybody knows you should do this, everybody mentions it ... and nobody directly shows it, beyond the shadow of a doubt how to! Until now. Thank you!
I agree. They talk the talk but won’t demonstrate. Amp repair is a physical thing with hands on dexterity. It’s really important to see the visuals.
I could not agree more! Been looking for a clear demonstration for almost 20 years. I’m still scared of those caps though...
Totally agree!!
Showing it opens up to liability when someone attempts to do it wrong..
@@ryans9029 Well, isn't it the same for kitchen knives or ... a pillow? Just wait for someone with a special gift for doing things wrong and they will do it. The rest of us don't mind tips and info in videos! :D
Around 1970 I got hit full force by the power supply in an unplugged 50 watt Bassman. At the time I had no clue at all what I was doing. I heard a loud crack, and the room literally turned bright blue for a fraction of a second. I've learned a lot since then!
That was a primative version of the blue screen of death.
@@lcagee he's lucky he didn't see the white light...
A bit more about putting a hand in your pocket while checking high voltages. What is really dangerous is current across your heart. By keeping a hand in your pocket, the charge will typically run down your arm, down the same side of your body and out to ground. Great advice and a great video.
OMG...you would make a WONDERFUL science teacher. You have an Isaac Asimov knack for explaining rather complicated subjects in the least complicated manner. You are a great communicator. You may have saved lives with this video.
Thank you for making this so straight to the point! Its much more helpful than other videos I’ve seen that way.
jamesylew thank you for the positive feedback!
If you need to mess with things with the amp powered, using a GFCI outlet is a good idea, in addition to the one hand rule.
The one hand in pocket trick was the first thing they taught us in electronics school. I was working on an old TV in the classroom and touched the terminals of the crt with my hand that should have been in my pocket. The whole class heard the snap as the spark entered my finger. The instructor used me as an example of what not to do. I wasn't hurt but I felt really stupid for the rest of the day lol.
Really good. Pleasant, concise and informative. No time wasted, which is a welcome change.
This is the clearest explanation on discharging caps I've seen. Thanks!
I had my 1960s Vox Ac 30 TB launch me across the room when I was 19. Never got caught again. 👍
seriously THE most important step before tube amp maintanence, when I was younger i blew up a death cap in an ACOUSTIC P.A, i was lucky, sprayed in the face with shite, no eye damage, still have the old weld damaged screw driver, and ma mom.beat the crap outa me for the smoke and bang my inexperience caused. NO JOKE, LEARN THESE PROCEDURES !⚡☠️⚡
I was just thinking to myself that I’ve never seen this vital step covered by any presenters/techs in their videos. My books show some sci-fi contraptions for discharging cap’s 😆 Thank you
I saw somebody play through the amp while they turned it off and it discharged the caps down to around 2v. All they did was strum, very, very hard until the sound died after turning off the power.
When working with electricity and other tools I treat them as if they are out to get me. Keeps me focused and not taking things for granted. (This is good for driving too! Someone among all those cars is looking to crash into me if they get the chance!)
Nice video, the main danger with using two hands is that the current flows across the heart and stops your heart. One hand means a nasty shock but its more likely to go down arm and leg and not across the heart.
Very nice to see a woman working in a traditionally male role. I have worked as a technician my entire life and have seen very few woman technicians. Great demo. Well done.
A full troubleshooting guide on how to read amp schematics and know what the parts on the chassis are would be a HUGE help.
Hello Colleen. Very good tutorial on discharging caps for safety. I remember my first AC/DC THEORY class in college. My instructor taught me the very same "one hand in pocket" method as well as the cap discharging with a bleed resistor. Just like discharging a CRT from a tube television. We used a special high voltage probe for this. I was so scared to death on those things, possibly imploding if not careful. RESPECT VOLTAGE/CURRENT. Never ASSUME, or you will make an ASS out of U and...yourself. LOL
Great textbook demonstration. Short, concise and to the point. All major points covered. This is the video I'm going to refer people to who are new to amp building. Great work!
That was very good. Anything like this always takes me back to roughly 40yrs ago when I was studying electronics in college where, using only mA ,we were taught to discharge by using a screwdriver across the leads.....of course, being a guitar player, I decided to build my own amplifier and, sourcing the instructions from something like ‘practical electronics’, went out and bought all the components.....some of which were electrolytic caps and a mains transformer, tapped to supply 6A (I think)......anyway, long story short in my enthusiasm I forgot that I wasn’t in college using mA and proceeded to discharge with the screwdriver.....my whole world turn green and blue for a while! 😳 taught me a painful, but valuable, lesson 😀👍🏴
Great demo. There’s also an Old School tool from ham radio days sometimes called a chicken stick. AKA voltage discharge tool. Stew Mac sells an affordable one and you can make your own. It gives you a more stable tool with longer reach.
One thing she didn’t mention was the power value of the resistor. Note she’s using a 5W. Keeping in mind P=V^2/R, dissipating 100V in a 1K resistor will still be 10W. You won’t smoke the 5W resistor as that is not continuous power, but... if you happen to be discharging 300V and you have a 470 Ohm resistor, it’s gonna get hot. Go for a reasonably large power resistor and I wouldn’t go less than 1K myself.
Not trying to be over critical, but you can’t be too safe with high voltage. And keep that other hand behind your back. Wear insulated shoes, too. Not like me who walks around barefoot all the time. Feet on concrete is a surprisingly good conductor.
Especially with sweaty feet. I have heard stories of musicians being electrocuted with electric guitars or microphones. Crazy.
Finally, a video that gets straight to the point, with clear and concise steps, including the safety measures. Thank you.
I’ve been searching for clear instructions on this for about three days. This is the clearest explanation and demonstration I’ve seen so far. Thanks for sharing your expertise.
I'm late to the party, and I'm sure I'm not the first to say thing, but I'm happy to see someone show how to do this without just whacking it to ground with a screwdriver. With the wrong set of circumstances the screwdriver could end up embedded in the concrete behind you-visible through the screwdriver-shaped hole in your head.
4:10 I had a journeyman say to me "if you ever assume, assume you're wrong". Little did he know, that statement had a profound effect on me. It made me realize, not even just safety wise, that you should know the problem and prove it. Never assume you know because that's when you become a parts changer.
It's definitely more pleasant listening to a woman's voice, and very good at explaining everything ;|)
Colleen! This is exciting, looking forward to watching your videos!
Best video on the topic that I've seen. Thank you for this straightforward explanation.
Nice one! You have a nice presenting style, looking forward to seeing more.
What a great explanation. Straight to the point and well shown. Thank you for being awesome!
Thank you for this. Just recently discovered you, gonna watch them all as I have time. Subbed.♡
God Bless you. In all my years no one has ever shown this. Thanks for demystifying things and for making the world a safer, more musical place!
Thank you! I don´t think I ever seen this properly explained earlier. Much appreciated!
Keep us up to date with all the safety tips, thanks.
I'd love to see a video on biasing a late 70's twin reverb, even better one of the 135 watt ultra linear twins
Good to see this safety point emphasized so clearly, as 450v DC with a high current, can be lethal!
This was such a wholesome video to watch, thank you!
Always wondered how to do this properly! Thanks for showing us!
Thank you for presenting all of this so clearly. I have wondered about it for as long as I've been hearing cautions about opening up tube amps, and never had it explained. Much appreciated.
This is so sick. Fuggin’ guitar tech. What a badass.
i love how this is such a "no bullshit" video. great video.
LOVE your practical, no-nonsense approach!
I'm currently repairing an old Sega Genesis and had flashbacks of when I repaired a camera and got a zap so I went online to learn how to discharge capacitors and found your video! Thank you so much!
Wish I still had my Sega. Man, I used to play Sports Talk Baseball nonstop back in the day. That was one of my favorite games on that console.
@@blazer6248 a great classic. Sadly, playing on emulators really don't hit the same way as on a console but sometime it's the only way to be able to play certain games again. :(
Good to actually see it done, and also like the additional little bits of information like the markings on the capacitors etc, well done, great basic info, good video, well delivered :) thank you
Supercool video!
Very clear and straight forward, no annoying music or unnecessary bullshit, so enjoyable to watch!
I would never open a tube amp by myself, since I might die in seconds. :-D But I love to see so much expertise on those devices. Especially love the sound of old Fender Champ amps. There's something magical about them ... Great job, keep going! Cheers
You are so right about always check, never assume! I once worked on a UK domestic installation I was told was dead - in fact, the neutral feed was broken, and the whole system, line and neutral, was at 240V. I checked first, or I wouldn't be writing this!
The gun is always loaded ...
Here's my most recent "getting shocked" story: Almost completed refurbishing a '68 SUNN 200s. I was finishing setting the bias, and was letting the circuit fully warm up. So while I wait I decide to solder something else I was working on (replacing jacks on a pedal). However the spool of solder unrolled across the exposed SUNN circuit and delivered to me a nice jolt.
Oh, I had a good (bad) shock from a Standel that used a pair of 6DQ5 tubes with metal (bare) plate caps. I reached around the back to turn off the power switch. Around 550 or 575 volts. In my tube amp designs I generally have a bleeder resistor in the supply.
Awesome ,GREAT EXPLANATION OF YOUR TALENT, THANKS FOR THE INFO ON CAP.DISCHARGING. KEEP UP THE GOOD WORK .🐟😎🎸🔊🎶☮️🎼 BOB.
Thanks, Colleen. Very clear and direct, which is appreciated and important!
Thank you. I ordered that resistor and look forward to being safer when I work on this gear. Your presentation is clear, concise, and delivered in such a laid-back tone that I seem to soak up all the information.
You are so right. This gal is a great teacher. It takes one, to know one.
You order that resistor? You don't have an electronic store nearby, that sucks waiting on parts. I'm waiting on my guitar lol. It sucks.
its possible to make your own resistors if you need one in a pinch. Salty water has a resistance as a function of the distance between the electrodes in the water and the salinity of the water.
Very informative video. You probably saved some lives here.
Holy shit, thank you CZcams algorithm! I am now suddenly into amp repair, big time! 😁
Thank you for your clear and helpful instruction!
I’m so glad I found your channel I get so much out of your content. Thank you and keep posting. 🙏🏻
Colleen, this is a great video. Thanks for posting!
I like how you describe/teach things! Subscribed! Thank you!
Great video and you're so easy on the eyes! Thank you for posting this!
I can’t wait to to start working on mine. I’ve been looking up a lot of safety videos and yours is the most understandable and helpful! Thanks you!
Very well done, young lady! I'll be looking for you and more of your direct and easy to watch videos in the future - Richard
Excellent, I will watch all I can. Thank you!
This is an excellent tutorial, and will probably save some lives. Thank you!
Thanks a lot for making this content ! I’m trying to repair an old Bass amp, it hasn’t got tubes, but fairly big caps. This is a very nice tutorial. Keep on the good work :)
I was just wondering about this and this video showed up in my feed. Crazy algorithms. Thanks for the video. Good tips
Your Fluke 114 has an "AUTO-V LoZ" Setting. In that mode, the meter has a low input impedance, in your case about 3kOhm, if i'm correct. The manual should give more details.
So you can discharge your capacitors using the DMM in AUTO-V LoZ and monitor the discharge process at the same time, and you don't need any extra equipment to do so. This function is also handy to get rid of ghost readings.
Your video's are so good because your approach is very simple and straightforward with very good illustrating. No fancy ego-tainted dialog, just "the facts". THX !
Thank you Colleen for clearly demonstrating how to completely drain the filter caps!
Great Video!
Thanks for this helpful video on how to safely discharge capacitors in an amp.
This is a great public service. You may have saved a life. Consider me subscribed!
Thanks Fazio, you explain this so well and make it plain and simple enough that even we musicians can understand.
Absolutely very well explained in detail, thumbs up!
Thank you!
This is, by far, the best example and description of this that I have seen! Thanks a bunch! 🎸
This is the first video I've come across that thoroughly explains this. I've been collecting and trading guitar tube amps for decades. Thanks! Subscribed!
Perfect! Thank you for doing this video. You're very precise. Much appreciated!!
Great video for people getting started! Nice work.
Repairing, constructing, and appreciating vintage audio circuitry is how I got started in my lifelong love of electronics design at age 10 or so.
Terrific series of videos; interesting and informative even to someone for whom most of this is way over my head. Interesting to watch in same way I find myself watching Uncle Doug. Sorta like getting some sense of what's going on inside my tube amps in a clear manner.
This is brilliant, thank you. I need to open up my '79 Twin this weekend and will follow this completely.
Very straightforward and informative video. Thanks!
Thank you Colleen, I have been reluctant to check inside my amp for fear of getting shocked according to vendor and tech.
Thank you for all the wonderful info. Great work!
Colleen, I have watched all your videos to date, and I have learned so much from you! I like how you state what an amp symptom is, how you diagnose the problem, and how you describe the method to fix it, with all the things that also need to be done. You cut through the BS of most of the other amp techs I see here on CZcams, I mean, how long should a viewer be made to suffer just to see the UNBOXING of an amp? And I like how you stress safety in this video, people underestimate electricity so bad that it's sickening. I worked in the electric utility industry for 32 years, complacency can be deadly. All that aside, I want to thank you for bringing your videos to us. I wish you the very best in your endeavors!
Thanks! I usually just fix guitars but I was given a vintage Ampeg SVT in need of refurb. I have been apprehensive about working on it because of the legendary legend of these murder caps, but your explanation was great and to the point. Noice!
Congratulations from Spain! Take care.
Colleen, Thank-you for showing that !!! Safety tips are always very helpful and can save someone . Enjoyed watching 👀....
I just finished repairing my bandmate's amp the other day... this would have been reaaally great to know how to do beforehand. Thank you for the info.
Great show. Will tune in again. I like that you are showing the want-a- be repair personals safe and true ways to discharge Caps.. Keep up the Good work.
This is how you make a good informational video. Great job.
Thank you! I have two Sansui units that I will be recapping soon, and could find nothing on discharging the caps. I always used a screwdriver, but those were in HVAC applications, not stereo equipment. I figured it would be something easy and safe like this. Thanks again.
Wow, thanks! I definitely learned a thing or two watching your video!
FINALLY someone shows how to do this properly. Thank you for posting this.
Hottest amp tech I've seen yet, wish you were in katy Texas, outstanding, well done video
Really good tip. I like how you use a resistor to drain the caps. I believe that is the best way.
Excellent, clear, and very straight forward video. Well done!!
Excellent video - Even with all my years of electronics repair, it's good to have a refresher in safety!
Excellent demonstration and a beautiful calm voice, thank you ❤
I dont know how I stumbled upon your channel but I am taking automotive electrical courses and it’s so cool how I know what you are talking about (most of the time) and I can read wiring diagrams for speakers and amps even though I’ve just had practice with car wiring diagrams. But I really like the vibe of your channel no cheesy music in the background and a chill host
You shocked me, Lady! Nice post. Thank you
Very well done. Best video on this I’ve come across.
At last! Thanks so much! All I needed was to SEE the procedure and it's been a closely guarded secret until now!
I’ve always been spooked by this, but now it’s very straightforward. Great concise content!
Definitely. Some seem to want to make it more complex than it should be. I get nobody wants to encourage people to poke around willy nilly, but this is as direct as it can get.
@@Scott__C Yep, it hinders sales :). If people know how to mod themselves, they'll buy less expensive amps and just modify the ones that they already have.
Thank you! You’ve earned many good Karma points.😊 I’ve been wondering how to do this for 30 years. This is the first video I’ve seen that actually clearly and safely shows how to do it.