Recapping: It's the New Bloodletting
2022 ж. 2 Шіл.
20 129 Рет қаралды
Replacing capacitors is no substitute for repair. It is not a panacea or cure all. Reasons to recap are discussed, as well as horror stories of recaps gone bad.
Replacing capacitors is no substitute for repair. It is not a panacea or cure all. Reasons to recap are discussed, as well as horror stories of recaps gone bad.
Every single thing you have said is 100% on the mark. I am a professional repair technician and electronics engineer. I have over 45 years experience repairing domestic and professional audio as well as broadcast electronics to component level. I admin a Facebook group and this topic kept popping up and resulted in some really nasty arguments between members - especially from people who believed they were right - that blanket replacement was the way to go and no one was going to tell them otherwise. It got so bad that I issued a directive that there are to be no posts about capacitor replacement that would result in people debating the idea. In another groups I read several posts relating to units that had been "fully recapped". In one, not only did it not fix the original fault but it resulted in new faults appearing - the worst being that the unit was now oscillating at some high frequency. What a lot of these people don't realize is that in blanket recapping, they are often taking out very good quality capacitors and replacing them with inferior quality ones - for no good reason. I am over it. I am sick of arguing with people who think they know better. People who think that because they have watched a couple of KZhead videos they are now experts on the subject. Never mind my years of experience on a wide range of equipment and all the training I did to enable me to do this. Training that taught me how to trace and identify faults in electronic equipment and the correct procedures to remedy them. It is infinitely useful to have your wise and insightful video about this issue and I will be referring people to it from now on!
Thank you for this commentary. It's always nice to have your viewpoint confirmed, but especially so from someone with your credentials and experience. The internet has brought an amazing array of knowledge to the masses. Unfortunately, it has also brought forth an amazing amount of misinformation, which to a person with no technical background or education is swallowed whole. It's why I refer to it as "the new bloodletting"; recapping is seen as a panacea, much like bloodletting was when there was no knowledge of human biology. Then there's forums and social media, where apparently it's OK to shoot the messenger if they disagree with you. It's one of the reasons I post under my real name; I'm a little more circumspect before I hit Send. Then there's the whole "cork sniffer" cap thing, where ridiculously priced capacitors with equally ridiculous claims are discussed. How this cap will give you "more detail in the upper end", or some such. It cracks me up when you think about the average age of the guys in the audio world. They'd be lucky if they can hear above 12 Khz. There's a guy who aggregated a bunch of threads of recaps gone bad. I read a few of them on the video. Here's a link: audiokarma.org/forums/index.php?threads/wow.915320/
Great advice, Ray. Fix the problem first, then recap if you feel the need. The only thing I would add is check every feature before you do anything so you know what works and what doesn't. That includes making sure tuner sections work and actually provide stereo. Nothing is worse than getting deep into a restoration, discovering something isn't working, and not knowing if it was that way at the start or not. Ask me how I know. 😁
Good advice! I have fixed a few items bought off ebay. I have found broken traces and bad contacts more than bad caps.
Very good advice. There are too many zombie-techs who recap everything they get their hands on. The other mistake some people make is to assume all problems are caused by bad caps. So they replace caps randomly, expecting that to solvd the problem. People need to learn how to trace a circuit and to find where it is not working correctly. I began learning that when I was 8. I hung around a local radio TV repair shop and learned from the kind old fellow who owned it. I would tell him if the horizontal oscillator was working, because I could hear it. He had a method for repairing tube TVs. You tap parts of the circuit with an insulated screwdriver, going from the IF to the audio section, until you hear a noise in the speaker. Methods like that can be applied to solid state circuits, but you need a schematic most of the time. I rarely have to replace capacitors.
Thanks, William! True, there are those who believe recapping is a panacea that will cure all ills. Or turn their Yorx all in one into something akin to a McIntosh. But the really sad part is the person who decides to recap a working unit, only to introduce a problem they don't have the skill to troubleshoot. While I feel bad for those folks, you don't cut your teeth on something you care about.
What this video leaves out is... it really depends what you're working on. I looked at the rest of the channel and Ray seems to focus more on audio equipment which is lower heat, lower power, and (in some ways) less sensitive to caps going out of spec. Where as I mostly restore old CRTs. Those are usually higher power, higher heat, the insides of them cook caps after a few decades and their most common problems can all be fixed with a recap. (Particularly trinitron's vertical linearity). I look at it like changing your oil. If you have a vague issue with your car, start by changing the oil and performing all the maintence that you may have been lax about. Sometimes it'll fix the problem. Other times, it's something that needed done regardless. And, in the case of CRTs which are /fucking heavy/ and annoying to get apart... if you're pulling boards to recap one thing, you may as well just recap /everything/ since they're all 2-3 decades out of their intended life regardless.
This has to be one of the most underrated channels on KZhead. I love the honesty, the up front practical approach. You just get in there without hesitation and show the core of what was done. I've only watched 4 of your videos, they are all excellent. I have a lot I can learn from you. I am thrilled that I found this channel. It's really excellent!
Thank you so much, Alex! Comments like this just make my day.
I'm waiting for it to take off! I'm gonna help by mentioning it in larger channels. Absolutely excellent content!
It really depends what you are working on. I recapped an old 80s computer today. It used 25v 1uF electrolytics. One cap (right under a heat sink) was leaking 45mA at 9 volts! It was no longer functioning as a capacitor. It was now functioning as a resistor and adding extra load to the voltage regulator, making the regulator run even hotter, and exacerbating the problem. So, in any device that runs hot as part of its normal design (e.g. a TV) I would recap the electrolytic caps before anything else. There are exceptions. There is a guitar amplifier: The Sessionette SG75. It's so well designed, and the components so well specified and so well placed that after 40 years the electrolytics are all perfect.
It does indeed. While I aimed this video at the audio crowd, where recapping has become a cure for all ills (it's not), there are cases where it is warranted. I have an NAD preamp I got in a lot of equipment I purchased. Every single electrolytic (with the exception of 4 Rubicon's in the phono section) where measurally just awful. Contrast this with a Marantz 2230 I recapped for a buyer, where every single cap measured well within spec, and this was manufactured between 1972 and 1974!
Awesome video! Thanks for sharing.
Great advice. Thank you.
Yes indeed, fix the root cause first. And then, if there's budget and enough patience, look for other suspect parts. But, in all cases, strive to be the person that doesn't let the smoke out.
Thanks again Ray!
Excellent advices Ray, as always. LOVE your Channel. Peace man
Thanks for the kind words, Luis!
Ray, thanks for sharing your knowledge with your videos! I'm a relative newb to repairing solid state gear. I built a lot of tube gear in the past, but I'm learning a lot from guys like you. You hit the nail on the head about fixing the problem first and then taking a zoned approach if you want to recap a unit. Thanks again and we'll see you on AK! TomSc
Thanks Tom. I was hesitant about doing the video thing, thinking there are so many electronics channels. But the comments have been overwhelmingly positive.
Great video Ray .
Thanks Jay. The whole recapping thing has gotten way overblown. I recently recapped a Marantz 2230 for a friend, and out of curiosity checked all the electrolytic caps I had pulled. Not one was bad. That receiver was produced by Marantz between 1972-1974, so we're talking over 50 year old parts. But 50 year old QUALITY parts. Yes, electrolytic capacitors can and do fail. Just not as much as we're led to believe.
Good point Ray !!
Yup. Two years full time technical school. Gave me the basics but no substitute for experience. Probably at least five more years before I really had much by way of troubleshooting skills.
And we add to them every time we work on something.
👍 you just boosted my confidence, thank you!!
Wow, that is so great to hear!
I have been fortunate to have a friend who is a retired tech, and he was a real help when I started out, and still is when I’m stuck. His best advice mirrors yours Ray. Get something cheap and learn from working on it. I started with a Zenith console and moved up from there. If you are starting out, some of the lower powered Technics receivers like a SA-80, the SA 101 and 202 can be found reasonably priced, and the internals are laid out to be very accessible. I learned a lot from them.
Your friend steered you right, and having someone mentor you as you learn is as good as it gets.
Thank you ! I needed this advice.
Thanks for your comment. While I can't speak to whatever you're dealing with, fixing it first is just a best practice.
I didn't hear any ranting, just good sound experienced advice. Making my way through your videos as a new subscriber. Watching and learning.
Ex-Sony audio engineer here, it's all true, I see people recap stuff arbitrarily because they think they have to, usually with much worse quality components than the ones they are taking out and then wonder why it sounds worse. Personally, if I suspect a cap to be faulty, I'll take it out and check it with an ESR meter, if it's fine it goes back in. I guess what I'm saying, is, unless it's leaking all over the board or has exploded (or on rare occasions open circuit) most caps are pretty reliable. Keep up the good work, Ast...
Thanks for the confirmation, Aston. The whole recapping craze has gone viral. The worst cases are where people take a working piece and recap it, then it no longer works. And in those cases, the owners don't have the skill/experience to find the fault. I'm going through a Marantz 2230 now. The buyer is paying for a recap. Not one of the caps pulled measured badly. Not one, and these units were produced between 1972 and 1974. OTOH, I got an NAD 1300 in a lot of equipment I bought, and only 4 caps in it measured good, 4 Rubicons in the phono stage. So there are those rare cases where a full recap is warranted. Just nowhere near the amount that we see/hear about. I guess when the only tool you have is a hammer, well, you know the rest!
Oh, and surprisingly I've not gotten any negative responses to this video. Which surprised me. Audio is one area where shooting the messenger is common. 😁
@@raygianelli3612 I guess quality caps back when Elna's and Nichicon's were being fitted, they were built to last. The dark period was when all the companies across the spectrum bought an enormous batch of caps where the chemicals were incorrectly formulated in the early 90's. This mostly affected surface mount caps, but we're all still resurrecting technology suffering from that mistake all these years later. Lots of Sony / Panasonic / Technics and even Sega. P.s. Good information is always well received. Regards, Ast...
Your so right about this,specially when caps and transistor are guided in the wrong direction don’t ask how i know this great class ray as always
Hi. I just recently found your channel. I am THOUROUGHLY enjoying watching it. While I don"t have any appreciable skills to repair this type of equipment, I can do the light work (repairing the mechanics). The audio work I shall leave to the pros. Thanks for being another S FL. person.
Thanks for the kind comments! Keep watching and learn along with us. You'd have to thank my parents for me being a South Florida person. I was 12 when I was dragged here against my will. But I got acclimated to the heat and never left. 😁
Bravo - I just discovered your channel, and am now subscribed ...
Welcome aboard, Bill!
Just getting done with another SX-780 and after I troubleshoot it I rebuild the power supply and filter caps and I do a load test and out the door it goes. Unless I find a bad cap in my troubleshooting I don't re cap a unit unless I am asked to. I also have a 94 KLX650 on the lift that is as worn out as you can find. But will be as revived as any Pioneer I've worked on. You just can't beat the vintage stuff.. Love your videos Ray
I agree. I just recap things for people who wish to pay for that, and certain items to enhance resale value.
This is perfect advice! As someone currently studying mechatronics engineering and has an interest in audio equipment, I occasionally dabble in recapping *working* equipment to see how it affects the sound. I only do this in equipment with cheap electrolytic capacitors, so if nothing happens, I end up with better capacitors in there afterwards. Otherwise, I only replace parts that need to be and fix the problems first. Depending on the age (80's and older) I will recap because of better production quality in modern capacitors with capacitors of the same types (low ESR, low impedance, high temp, long life, low leakage, etc.) to avoid causing problems.
Your approach makes sense. I made this video after reading countless posts from people that had tried to repair something by recapping it, only to make matters worse. Or had a previously working unit that they wanted to improve by putting new capacitors in, and rendered the unit nonfunctional.. The internet has helped spread the idea that recapping is a panacea, a cure all. Electrolytic capacitors can and do fail, and can be the only problem. But they're not the only thing that can. The other idea that gained acceptance is you can improve the sound quality by the use of higher quality capacitors, the more expensive the better. And they claim they can hear the difference. The only time that will work is if you replace defective capacitors with good ones.
Got a bunch of amps that I bought for cheap, with different problems Vincent SV-388: Outputs are either muted or "hovering" in and out with scratchy sound when the input signal is low enough. Same issue with every input (analog and digital). Even happens with normal input levels with music that has some quiet passings. Also the the two main channels have a serious hissing problem. Alto Mistral 400: Audible distortion or maybe I'd call it an oscillating higher pitched "ghost" sound at low frequencies at any volume. Very noticeable with sine tone, as it varies with frequency. Audac DPA 154: Noticeable distortion or some harmonic(?) sound that varies with the sine tone frequency. Two 100 uF 50 V caps near the speaker outputs run very hot. Ecler LPA16000: Sometimes the audible clicks from the switching power supply can be heard through the speakers.
Father was a amateur radio operator built all his own equipment taught my the basics and had me build a lot of heath kits then troubleshoot the ones that did not work at first but i still learn somthing every time i work on my equipment
When I was very young I watched my father take a D cell, a wire and a light bulb and make it light in his hands. That started it all for me.
Very well said Ray!!! Im an aspiring new tech and have tried so hard to learn from guys like yourself and some of the greats on AK. I troubleshoot computers and software for a living so alot of the best practices carry over in theory. Always repair before recap, always check the service manual and the board label but most importantly take pictures of how the part was in before as the board and the manuals can and have been wrong.. Its been a fun journey so far, Ive fixed a few receivers, ive also made things worse. What a fun hobby and hope to keep improving. Keep up the great content as its very enjoyable to watch and learn!
Thanks! Troubleshooting can be boiled down to a few basic steps: what's it doing (or not doing)? How does it work? How is it deviating from how it should work. That said, you can get some curveballs that will test your patience and your sanity. Yet those can be the most satisfying when you figure them out. I've often said my only superpower is that I simply refuse to give up!
@@raygianelli3612 You got that right, Just recapped a Marantz 1060 ( pretty straight fwd unit ).. Yet caused some funky issue on the p700 board that threw me for a big loop.
Great video as always Ray like you said work the problem Don't make it worse by guessing
Thanks! Like most life lessons, I had to learn this one the hard way, and although that was working on cars, it applies to any kind of repair.
Absolutely true
Thanks
I See your point, and finding the real cause of a fault instead of simply recapping and hoping to have fixed the problem, is the way to go. But I had countless cases in which the Caps were the sole Problem. In my case especially in Devices from the 70s and early 80s, mainly Synthesizers. Those Machines run on borrowed time, so I made recapping all Electrolytic Caps on those, part of the refurb-routine. I don't even check if they are still good, they all have to go. It gives me a huge peace of mind, especially if I do not plan on keeping the device I refurbish for myself. And the difference in Sound is most of the time hearable, at least with synthesizers which are prone to distortion when driven hard.
In your case it's probably the best way to go. I was motivated to create this video after someone on an audio forum aggregated recapping gone wrong: www.audiokarma.org/forums/index.php?threads/wow.915320/
I occasionally fix equipment for others. I just do what needs to be done to get them working. When I get bored, I take on recapping my old equipment that does work. If it doesn't work, I fix it first. I just recapped my SX-6000 but I take my sweet time. I replaced all the caps except for the tuner boards which I don't normally do since I don't have the needed equipment. I was thinking of doing them but the back of the boards were hard to get at so I will probably not bother. I never listen to the radio anyway. I am fairly new to this but have a BSEE from 35 years ago.
Well, your BSEE from 35 years ago serves you well when the equipment we're dealing with is usually older! This is a great pastime that helps keep your mind active, and provides satisfaction when you fix a problem. Keep it up!
You are right ! As a technician, I recommend changing the caps after 20 years of usage for an amp if you use it everyday. For other equipments, it is more a case by case scenario, but if something is not working properly, it won't be fixed by replacing capacitors only, even if the capacitors themselves have failed, their failure brought other problems along the way. Great video! Very informative!
Thanks Yves! I was motivated to create this video after reading yet another case where someone tried to fix a malfunction by recapping, only to create more issues or even rendering the item inoperative. The internet has spread the idea that recapping will cure all ills. If only it were that easy!
It is fun when we listen to someone who know his stuff! There are many people on those channels that have no expertise and experience and they give advice only based on hearsay and they create more confusion.@@raygianelli3612
Thank you for your advice sir, I’ve personally got an eventide 1745 A and an Ams Dmx 15-80s that I’m trying to keep alive and I’m just now learning about circuit maintenance, the eventide isn’t even working at the moment but i believe it’s the power supply.
Man, I remember lusting over that Eventide stuff back in the 70's! Good luck to you as you work on these pieces.
@@raygianelli3612 thank you I’m gonna need the luck
Thx for the info, great as usual. I have several Sansui 1000A tube receivers. They will all need restoration. I will not be doing the work. WHEN ( LOL) I find a tech with the right equipment, will the normal procedure be to power the untit up slowly to discover any possible issues that may be in need of addressing even though the capacitors & numerous parts on the underside will be replaced? Just give it an initial firing up and see how it responds? Ty
Powering those up at their age is not advisable. And due to the high voltages found in tube amps, it's an especially bad idea. Best to replace any paper in oil and electrolytic caps first.
Great review Ray! You explained it better than anyone else in any other video. The question I have regarding the caps is, I have an original Sansui 5050 receiver that I took the cover off for the first time, that has all the original caps - I observed that most of the caps are the light blue Nichicons, along with some black Nippon Chem-Con caps and large filter caps, and some light grey Elnas scattered throughout. Is there any particular reason Sansui chose caps from several manufacturers in lieu of sticking with just one brand of cap, i.e., only Nichicon?
Hi Arnold! I really don't know why different brands were chosen, although I would suspect it was a matter of economics, what they had on had etc. There's really no "one size fits all" answer to whether or not the caps are still good. Hours of usage, heat, storage all play into it.
Recapping can cause more problems than it fixes. Old Caps had different conduction curves. Newer ones can have same specs but turn on hard and cause current bursts that can overload circuits.
The problem with replacing caps on older units is the quality of the solder mask on the board is not always meant to handle rework and it’s very easy to lift traces and not even know it.
I collect old transistor radios if they are working ok it's best not to recap them. A radio that's 60 years old you're going to damage them trying to replace the capacitors.
Recap is not repair, but many issues are caused by caps being too old (keep in mind 40yrs+ for 80s and earlier machines). Recap is a good practice for every valuable machine that you intend to keep for years to go, and yes, it can sort out issues in about 50% of the cases.
I don't disagree with any of your statements (well, except 50% repair rate from recapping alone). But the internet has spread the false gospel that recapping will cure all ills. Or turn a sow's ear into a silk purse. Worse yet if you make an error doing the work and don't have the skills to find/fix your error, you' in trouble. Read this thread: www.audiokarma.org/forums/index.php?threads/wow.915320/
My AU-717 is getting capped as I write this. It had black flag caps in it. Those are known to be a bit leaky. A few were bulging, and while it did work it was down on power. The toroidal transformer was in perfect condition as well as the volume knob. This unit and it's brother TU-717 Sat in their factory boxes in a closet for 29 years. I got them mint and working well. I just like cranking them often. My Tekton Lore speakers can take what she gives and it sounds glorious.
Absolutely correct :- )
I do a recap mostly in the end stage of the repair, if necessary. Of course if there are symmetric channels, I do them on both sides, but if the cap is still good, I leave them there. It's a time saver, and the specs stay pretty much the same. Last I had a voice processor, the owner, "recap everything in it". But it was far from necessary. So everything was the same, except the pots, I cleaned them, and back in the DSP. Only in smps power supply's, I change every time the smallest cap, because that is the one, who gets the highest switching frequency.
Great advice. Would like to add using a dim bulb tester while you are modifying or changing components. I learned the hard way on a Carver amp - just made one or two component changes and didn't think I needed to use the DB -- Poof! I shorted something and all went up in smoke. So along with doing the zone changes and then testing, use a DB too. (Let me know if anyone wants a Carver to work on :(). )
Ouch! I feel your pain, Brett. I've learned some hard (and expensive) lessons myself. They sure stick with you!
Why do people think recapping is an automatic fix for all audio equipment ? Ray’s comments in this video are worth their weight in gold !
Thanks Herb! I made this video after seeing a thread on an audio forum. This member had aggregated horror stories of recapping gone wrong: www.audiokarma.org/forums/index.php?threads/wow.915320/ The internet has helped spread the falsehood that recapping will cure all ills. Not only is that not true, the inexperienced can cause more issues that they may not be able to solver, and it increases the complexity of the repair when a tech finally gets it.
Old saying... "When the only tool you have is a hammer, everything starts looking like a nail." Recappers know how to replace capacitors but rarely have any skill beyond that... so everything starts looking like a capacitor. Ray's skill is not necessarily in electronics (although that is part of the equation). His real skill is in finding and understanding the actual problem. The advice to fix it first is right bullseye on target.
@@Douglas_Blake_579 Well, I had to learn, since I can't be trusted with a hammer. 😝
@@raygianelli3612 ROFL ... Good Choice!
hi Rey, could you please make a video sometime, how to set the VU meters on the amplifier, if you come across any, it would help me a lot 😉😇😜otherwise take care, I'm looking forward to the next amplifier repairs.
Hi Ray, I have a general concern that I hope you could briefly answer to. I do have an old NAD, something is wrong with it and since I am diagnosing and must replace some parts I thought it would be a good idea to replace the electrolytic caps because they are by now about 30-35 years old. Generally speaking, do you recommend I pay attention to anything beyond the fared and voltage value? Should I purchase a specific brand, should I pay close attention to specific property values or anything else? I know that this is very general in context for you to provide specificity to any answer but despite this, maybe there are some general guiding principles that you might be able to offer. Thank you.
First off, buy all parts from reputable vendors such as Mouser, Digikey, Element 14 etc. Any electrolytics with orange wrapping are low leakage and should be replaced with same. Stick to brands like Panasonic or Nichicon. There are others that are fine but you should be able to find what you need from those manufacturers. Going up in voltage is fine, in fact any 6.3 volt caps should be replaced with higher voltage variants.
@@raygianelli3612 Thanks Ray, I sincerely appreciate the reply, it adds to my confidence when purchasing replacements.
Thank Ray. Just watched this and I am going to print and tape up a little notice. Fix-It First!!. In my radio shop. I have an older IFR service monitor I used to diag Two way radios. It has started acting up on start up. I thought, Oh ya, Ill re cap it this winter. After watching this video im changing my ways. Im gona get in it and fix it first. Then, if recapping is needed ill do it. Why through a bunch of parts in it just to hide the real problem further.
Like most lessons, I had to learn that one the hard way. Another one was if you find something wrong, fix it even if you don't think it's causing the trouble your chasing. More often than not it is.
Im with you on that one Ray. From now on.
picked up a used ADCOM GTP-500 preamp that had some issues with hum (and the tone control circuitry was out) when i opened it up, i saw yellow gunk all over a number of caps and assumed it was leakage from bad caps. didn't realize that wasn't much of an issue in the 80s, but jumped right in and resoldered about 50 of the electrolytics (and went ahead and replaced the styrols as well) it works, but that didn't fix the tone control issue which turned out to be a bad op amp. nor did it fix the hum, which seems to be slightly worse (and volume dependent now, i don't remember if that was the case before) also, i ended up killing the IR receiver section. i'm fairly decent at soldering and i understand the principles behind the way each individual type of component works, (read lots of adult electronics books as a kid) but understanding the various levels of theory behind how things come together in an amp is where i'd love to dive in more. i need to get some better books.
Doug Self writes excellent books on amplifiers. Highly recommended!
Exactly
I got a free Sherwood S-7100A and a JVC VR-5505 for $20. I recapped both of them for practice. I did find some caps that were corroding on the bottom or way out of spec. The Sherwood had a hum that went away after recapping the tone board. The JVC didn't make a difference. The phono board needed some new transistors though. I have better components I have picked up since then but have not recapped them because they sound good and the caps look fine.
Sounds like you're striking a good balance. Electrolytic capacitors can and do fail, and need to be replaced. But the idea has taken hold that recapping is a panacea, a cure all, when there are other things that can (and do) fail. And the unfortunate folks who attempt to recap a working unit and it no longer works is heartbreaking.
I understand recapping isn't a repair, but I tend to only get work that's 10plus years old . 50% of work has corrosion at the pads ,so if I'm going to test and resolder the whole board,I enjoy using my desolder just to change a few components that don't need tweezers to set . With that said , never understand the magical smoke . Your work is noticeable. Thank-you.
Ive been doing audio rework for the past couple years, and in the past year started recapping everything I can get my hands on. The only thing I can disagree with on this vid is that while I am paranoid and like to test after working on each section when possible, I've *never* had an issue actually pop up, especially like the stuff you described (knock on wood). Also, never experienced confirmation bias in assessing caps improving sound on old units - now I can talk about individual caps, new vs new and what impact that have...but simply gutting a vintage amp and putting in new parts has every time made a significant, sea change difference. (Also you were reading thread titles and someone said they still had a hum after recapping, criticizing the move. Its likely that he described the issue and someone blamed the filter caps as the possible culprit - the recap was an attempt at fixing, it was wrong, time to keep troubleshooting.)
The issues I described came from this thread that was aggregated from many: www.audiokarma.org/forums/index.php?threads/wow.915320/
great advice, and this applies to trouble shooting in general not just electronics. its flat out sound logic. if someone just wants to change out the caps and cross their fingers, they are just throwing parts at the problem. maybe it works out but most likely someone is turning a potentially easy fix into a basket case sitichiashun. *subscribed*
Thanks Dave, we're in 100%agreement on this. This is the thread that prompted me to make this video. This forum member aggregated quotes from various threads of recapping gone wrong: www.audiokarma.org/forums/index.php?threads/wow.915320/
I am from India, my JVC TT platter runs for 5 minutes and then stops.I have gone thru many videos and the caps are the target.I was to take my tt to a techie and ask to replace all the caps and tgen go for the real fsult finding.Luckily, today your vidro popped up and after going thru I have changed my plans.Thank you very much,yours is the video which is with the correct line and length.It is more important to read the circuit diagram and know the related things first .
This is very gratifying to hear. It's always advisable to fix a problem first, as occasionally we can introduce additional problems when recapping. And that can cause real headaches even for experienced techs. For those with less experience it can be unfixable. There may be a semiconductor overheating. A can of component cooler may help pinpoint the issue.
Thank you Sir for your prompt reply.Infact what you have informed is correct one transistor is getting hot but it is fixed with a heat sink.Only one other IC also gets heated but can not say for sure and the JVC has removed the number and name of that IC.The transistor number is D 313 V E9 M.I was unable to send thevphotis of the circuit of my TT.There are ICs also but those ICs are not getting hot.This D313 transistor is of regulator type if I am correct.
Hello. I need some advice on my kenwood C1 preamp. It's coupled with the M1 power amp and i notice an audible his which increases with volume. How ever if i increse the volume from dac the his remains at the same level no matter if the volume is max or min. Do you know where should I start looking? As you said i need to fix it first before recaping the unit. Also I need to turn the trebble pot to max to have a good treble in the sound.
First I'd need to ask some questions: Has it always had the hiss? Is it equal in both channels? Have you always had to crank up the treble?
thanks so much for sending the message .it gets tiresome how much people fixate on "badcaps" theres other areas of electronics that suffer urban repair myths too like pc/games consoles "just reball the gpu" and in inverters/psus "fit better mosfets"
Yeah, I chalk it up to folks reading stuff on the internet and thinking they can solve their problem by replacing capacitors. It's frustrating to see how many cause more harm than good by this.
Any recommendations for literature/a book for someone looking to get into electronics repair? (Specifically for music gear; amps, mic pre-amps, EQ's, channel strips etc) Also, any advice for a minimum piece of test equipment besides a multimeter? Thx
You really need a good foundation of the basics. There's no short cuts, or a single book that will get you there. You can find the Navy's NEETS courses online. They were used by every branch of the military. A multimeter will do 95% of your troubleshooting, but the other 5% will require an oscilloscope and signal generator. I did repair work for pro audio and guitar amps, effects and other music gear. It's all electronics at the end of the day.
100% spot on , re-cap job does not fix existing problems .
Thanks Joe. I blame the internet, because ironically while we live in the information age the net spreads misinformation just as easily. Anyone can post or make videos (I'm living proof), and there's no one to apply checks and balances.
As one of my friends says.... "Recappers are the new tube jockeys" ... if it's not a bad cap they can't fix it. You are absolutely correct in telling people to fix the actual problem first.
There have been just too many horror stories of things that were working fine, but the owner wanted to recap it for whatever reason, and now their item doesn't work. The internet helps disseminate information, both good and bad. This is one example, rampant recapping, which will cure all ills... except it doesn't, as you know.
@@raygianelli3612 Indeed ... all too well. Just before I retired, I had a pro-amp in protection. It would start up and randomly go into protection about 20 seconds later. Other techs had looked at it and by the time I got it, it was pretty mashed up. The foil to the relay coils was cut, a couple of zeners for the op-amps were running wide open, and it just wouldn't play. So, the owner wanted to learn and I agreed to give him a lesson. I started showing him how to follow the protection circuits. He pipes up, "Why don't we just replace all these caps and see what happens?" ... Simple answer: "Because then, if it starts working, you'll never know what the problem was, if it happens again." We fixed the relays, and the zeners and managed to get audio before the relays. But of course they weren't pulling in because the protection was triggered. A full day later, he finally listened and started checking the pins on the protection chip... "Ah, it thinks there's no AC"... a little more tracing and it turned out to be a 20 cent ceramic cap. Replace that and MUSIC came out. He would have replaced about $100 worth of caps and still not known what the problem was. To this day I still have a split fee structure... I charge my usual fee, plus an extra $10.00 per hour if my client is helping me.
@@Douglas_Blake_579 But...but...but if we replace the electrolytics with these magic capacitors with dielectrics spun from the wool of virgin's pubic hair it's just GOT to sound better! They cost 10 times what other brands cost so they just HAVE to be better. 🤣 Love your split fee structure!
@@raygianelli3612 Oh boy ... another story... My uncle used to run an electronic parts supply. Every so often he would get a customer insisting upon "Audiophile Quality" parts. My uncle would just smile, go back to the warehouse, pull the parts out of the regular bins, put them in red envelopes marked AQ, then jack the price way up and sell them to the customer. These customers left happy and many thanked him for keeping a supply for them. When I challenged him about the obvious price hike, he explained "They expect to pay through the nose for special parts and many would be wildly unhappy if they didn't". Of course everyone in the business knows there's no such thing as an "Audiophile Quality" part. Oh man... if these guys knew that most of these speciality companies do the same thing.
I had to recap two Nad C352 as all the caps were fails or way off spec. So sometimes recapping certainly is needed. Most fails I've come across tho are bad solder joints. But there is wisdom in your words, replacing good caps is a waste of time!
It seems like there was a period of time where NAD used really bad quality capacitors. I don't know if they were the result of the capacitor plague of the early 2000's, but to date NAD holds the record for newest audio gear with defective capacitors. The only other newer item that beats them are flat screen TV's. But SMPS are really hard on capacitors, so that's a bit different. Thanks for the comments!
What is the best process to have an amp checked over? I have been given a referral for a guy that appears to do repairs on the side. But he gave no directions other than for me to try and tell him a more detailed explanation of the problem.
The question I always ask is " what is it doing or not doing?". This may get an answer like " it's humming loudly", or " there's no sound from the left speaker." It gives the tech a starting point, and maybe a ball park repair estimate. That said, every item needs to have every function checked.
And don't be afraid to ask questions! At the end of the day it's your equipment and your money.
I just picked up a nice vintage pioneer that someone destroyed with grab bag caps now I've got to fix that mess so I can get back to the original problem
And there it is, an unsolicited testimonial. Like the good doctor says above, FIX IT FIRST!
The electronic version of a mechanic hearing "my boyfriend worked on it, now it does this".
It's funny 'cause it's true. 😝
@@raygianelli3612 Things break in a normal orderly way. Technicians understand that. I drive a 60 year old car that I hand built, there is no way I'm taking a soldering iron inside my Phase Linear 400. I did put White Oak main caps in it with success but they were bolt in.
To properly test a capacitor or any discreet component for that matter, it has to be disconnected from the pcb. At least , one terminal so you’re not reading the properties of the PCB. The real problem is that people take these videos as the end all and flat out get lazy. You guys do great work because you’ve earned that level of expertise through years of flipping through schematics, factory diagnostic flow chart and whatever else you could find. As time passed all that knowledge and technique became a part of you. The way all you guys try to give back and help through show and tell , in my opinion, has run its course. Insist your viewers seek out the flow chart for the model of scope and go through it with them. It’s not sexy or fun because it’s tedious work. For example, I’ve seen about 6 journeyman level electronics techs (or better)., have a flow chart , get distracted , come back to it, remember something from a decade ago so they disconnect something then start the monologue to the camera . Then at step 3 (or whatever) the chart starts it’s if / then algorithm. The journey seems into it but totally blew it because he had to jump in and try something, then forgot to make note of it and ends up invalidating the method that would’ve sorted the problem in step two. I’m sure that’s not at all clear and if you made it this far, you’ve had enough of listening to me. Diagnostics, in any field , is so satisfying once you get it. But you have to be grounded in the paper and ink for these abilities to grow. Thanks for the videos . I Always learn something.
I read this more than once, and TBH I'm getting a mixed message. On the one hand, you say videos like these have run their course. Then at the end, you thank me for the videos. Am I missing something? I do get that there's no substitute for putting in the work.
Agree with you Ray 100%, diag first then restore. When my "working great" ebay AU 717 arrived, ran it on the DBT. No sound from both channels with the relay on. Quick poke around, several caps swelled, every fusister open, nasty glue damaged components everywhere. In this case I had no choice but to rebuild all boards. Seller did give a hefty refund, and the plan was to restore it anyways. Would have liked to hear it in the stock form first, but not possible on this one. Got lucky, it played with no problems.
Good Job! You did all the right things in the right order. And had a successful outcome because of it.
@@raygianelli3612 Absolute correct. Right things in the right order. Best Regards.
@@treadmillrepair754 Thanks Ricardo. Good to see you here!
Very good point fix the problem first. I have done recapping and created more problems.
Jose, we all have. That's why it's so important to fix the actual trouble first, otherwise we run the risk of compounding the trouble.
Hahaha, for everything you ask about anything electronics is the caps, and if is Tek then is for sure the Tants. Great advice, always fix the problem first. Electronics failures usually cascade from or to somewhere.
I was motivated to make this video after reading about yet another recap gone bad. The internet has helped spread the false notion that recapping is a cure all (hence the title, the new bloodletting). To make matters worse, many times it not only didn't fix the problem but introduced new ones, which often were beyond the ability of the owner to diagnose and repair.
@@raygianelli3612 Sadly I know exactly what you mean, about two years ago. I bought a awesome Sony V6 monster receiver with the obligatory no sound or power. Was local and cheap. I found the blown fuse, put it on my dbt and variac, oh yeah definitely a short after a lots of troubleshooting since I'm a noob I double and triple check everything. I found some bias transistor and other stuff. I got power and then some sort of working unit, the last thing was the volume control, didn't work. So I went around and around, finally I posted on a forum. Two people shouted is this cap, happens all the time. So I did, something that didn't happen before happen now magic some cooked resistors. So now I bigger problems, I actually was so frustrated that, is sitting there waiting for me to go back to it. I fixed many receivers and other stuff since. After that, I ask for advice but take everything with 1/2 grain of salt. Long reply 🤣but had to be said. Again thanks for your replies.
Just picked up a Tek 485 victim of a recap!
Nice! There are deals out there if you don't mind wading in after someone else has mucked things up.
You must always understand what you are doing. Sometimes it makes sense to immediately change the capacitors, which sometimes will be a repair. Not always. There's no need to get into the device at all if you don't understand what you're doing...
I agree. Unfortunately, the internet has spread the thought that capacitors must be replaced. Even worse, there's now a school of thought that if you use certain brands or types of capacitors you can elevate the performance of your audio equipment. And since people hear what they expect to hear, they claim victory. You're right; capacitors can and do fail, and that's sometimes all you need to replace to restore operation. But as you know, they devices are more than just a collection of capacitors. Other things can and do fail.
@@raygianelli3612 I also really like it when I see that people increase the capacitance of capacitors and the diameter of the wires, but leave dirt and oxides in the switches and potentiometers )))
Needed to be said. Question, why is it most Elnas and some other brands from the late 60’s early 70’s test far above their original uF? I hear so many theories as to why. Sometime the discussion gets heated as you’ve perhaps seen. What’s your take Ray?
I agree, Mike. I was really hesitant to post this. I hope it didn't come off as condescending. It wasn't meant to. But yeah, as you put it, it did need to be said.
My take on the measured increase in capacitor value is that internal resistances (not ESR, maybe parallel) screws with the meters measurement methodology. Just a guess, TBH.
Wise words. I literally just made this very mistake. I recapped a cheap little Rota amp from the 70s. It was working pretty well but with mild speaker dependant distortion. Following recapping it was initally not working at all. I got one channel back though gain is low, but no idea specifically what went wrong. I have just been removing caps and reseating them Happily I paid more for parts than I did for the amp and, worst case, they can be reclaimed as nothing has blown up (yet). I did it for practice but will think twice about recapping a working unit again. Wish I had seen this video first.
Jim, we all start somewhere. You've gained experience, and that's priceless. There are many others who had a similar experience, but unlike you they worked on more valuable vintage gear. A member of an audio forum aggregated examples of what can happen. Here's a link: www.audiokarma.org/forums/index.php?threads/wow.915320/ Now you can attempt to repair the amp. Happy hunting!
Thanks, Ray, especially in replying to a year old video. I wonder if I could presume to ask a question and pick your brains. I dont have a schematic and wonder if I may have installed some of the very small value caps the wrong way round. The main caps are definitely correct but the markings on the tiny caps were unclear. Nothing has popped, but I understand they may not do so right away. Is there a way of telling if a cap in circuit is installed correctly by measuring voltages or resistance or capacitance or anything else, using a multimeter. Unfortunately I dont have a schematic yet. Cheers. Jim. No problem if cant reply. I have tried Google but cant find a clear answer.
@@raygianelli3612Oops. I left a reply and question above, but replied to myself in error. Thanks for your comment and if you have time to read my question avove I appreciate it. Jim
Hi Jim; You sure can tell by using a multimeter. Just put the leads on the cap, and look at the DC voltage. With the red lead on the cap's positive terminal and the black lead on the negative the meter should show a positive voltage. If it shows a negative symbol in the display, it's in backward. Most small caps can be replaced with film capacitors, which are bipolar in nature.@@jimfarrell4635
@@raygianelli3612 Thanks Ray. Really appreciate it. I will get right onto it.
I can't imagine spending the time & money for a recap on a unit that doesn't work.
You'd be surprised at how many do so in the belief that it will make their unit work again.
I have a 20yr old Elektra Power amp. Have the capacitor's gone out of spec and drifted in a manner that impacts the sound quality negatively? I don't know. I'm 100% adjusted to the amp performance and as the nature of humans shows often... we simply can't tell. That does not mean a change does not matter - it simply means we don't hear it if the degradation is within reasonable limits. Would recapping and perhaps replacing relays rejuvinate and create an amp that I hear with new enjoyment (in real terms if it was done without my knowing)... I don't know because I don't have the equipment to test the caps :P
I have to give this a definite maybe. The variables at play here are: 1) The quality of the original caps. I've pulled innumerable caps from 40 year old Marantz receiver that test good. 2) Heat exposure, whether due to design, lack of ventilation or storage in hot locations. I've seen caps that are far younger that are shot, but from here there's really no way to know. NAD seemed to suffer from this, but they're really the only brand I can mention. I've never seen an Elektra amp. Oh, and replacing good capacitors with newer, or "audio grade" caps will not make a difference, even though many claim so.
_" I don't know because I don't have the equipment to test the caps :P"_ Obvious reply ... get the equipment and learn how to use it... before ...you end up with problems you can't fix.
So true! If it's not from the 90's capacitor scourge, don't be so quick to blame the capacitors. It's so easy to test ESR and value before replacing them, but better yet trace the problem first.
Right? So many stories about recapping for the wrong reasons, then, even worse, causing malfunction. Sad.
If you remove them it doesn't make sense to put old ones back in
@@ericschulze5641you don’t have to remove them if you use an ester meter to test them in-circuit
Fair enough. But I have also solved many issues by simply recapping. Done correctly there is no reason why a new issue should emerge.
In theory, I agree. But anytime you start poking around in 40+ year old equipment, anything can happen. Wires can break, traces can break, etc. Electrolytic caps can fail with age. But they're not the only component in a piece of gear that can give you trouble. My main concern is that recapping is seen as a panacea, a cure all for any and all problems, and for those who decide to recap, looking for better sonics and wind up with a non working unit. Read the first post here: www.audiokarma.org/forums/index.php?threads/wow.915320/
There are folks who should do repairs and then there are folks who should not. Unfortunately, you can't prevent that so here we are. When it comes to a piece of equipment that's chock full of caps, I will only replace the ones that needs replacing and the ones that may need it. If you are doing this on a time and material basis, then speed is of the essence.
You can't just make a blank statement about recapping then bring in the car audio world without mentioning the capacitor plague of the late 90s and early 2000s. A lot of those Era amplifiers need to be recapped. Now I agree with you that if there's a problem it needs to be sorted and repaired, period. But if it's let say known culprit such as the Panasonic caps used in as example a Phoenix Gold M series, MS or ZX and there's nothing wrong with the amplifier. These caps should replaced, whether just being stored or planned for regular use. The capacitor plague has ruined 1000s of boards from leaking all over them and causing all sorts of havoc.
The problem is golden-eared audiophiles spreading misinformation about hearing supposed improvement after recapping. NAD of the late 90s, early 2000s used junk caps and need to be replaced.
That should be the only problem they've spawned. Some of the products I've seen make me roll my eyes so hard I'm afraid they're going to get stuck in the back of my skull! I don't understand what it is with NAD and poor quality caps. Maybe the bean counters staged a coup.
They probably reversed the wiring of the Caps? why it smoked!
Lol yup!
Like always in life it depends… Recapping a Panasonic VHS psu is necessary every five to ten years. Of course this does not solve the problem… but redesigning the psu or adding a an air condition to the psu? Of course recapping an excellent amplifier (of the past) is something very different. I‘m lucky to be a video guy, my problem is the unavailability of mechanical spare parts.
There's a certain segment of the audio community that thinks recapping is a panacea, a cure all. Yes, they do fail, but other components can fail as well. Then there's the group that thinks if you replace all the capacitors with expensive audiophile caps you can turn a sow's ear into a silk purse. But the saddest ones are the guys that took a working unit and screwed it up because they're inexperienced.. Don't learn on something you care about. www.audiokarma.org/forums/index.php?threads/wow.915320/
2 more things that should be touched on.. 1st: tantalums. there are claims that they only fail under excessive voltages. most likely true but they do still wear out and they are used quite a bit in the signal path and do drift over time and develop increased esr. this will cause degradation in sound.. 2nd: you stated "do not rely on the circuit board printing because it can be wrong" but at the same time, you can not always trust the values in the service manual because many times they change values during the production run. but like you said, be vigilant. pay attention to what you take off the board and the orientation... you also need to have some sense of what you are working on and the possible tech that may have changed a capacitor previously . such as a receiver i recently did and in the signal path there were 3.3uf capacitors. right channel was 50v and left channel was 160v. you need to be able to figure out that the 160v capacitor was "not correct" . . . it wasn't wrong per se ... it still did the job but if you are making a parts list there needs to be some common sense involved. and take pictures of everything from multiple angles. make sure you get the orientation of the caps. it's saved my butt several times. thanks for the video ray. i always look forward to them.
All excellent points, Joseph! And tantalums tend to short on failure, so I'm glad you brought this up.
@@raygianelli3612 i hear that they fail in spectacular fashion. taking out other components with them. i have yet to see this.
@@josephlalock8378 Haven't seen catastrophic failures that I recall, but a shorted tantalum took down the power supply in my Fluke 8920 AC Voltmeter.
People who claim their cars drive better after tune up etc are just experiencing confirmation bias?Not so easy for car drivers to accept is it❤❤❤❤
It all depends if you're replacing bad parts with good.
If its aint broke, dont fix it. Recap only when caps are really bad. Also im a fan of original vintage. That means i dont change Old transistors, original, with New Just because Old are noisy etc.
Well, there's noisy, and then there's NOISY. 😁
Total newby.... If a capacitor is down, how can it be repaired. I have only heard of replacement.... I mean if their stuffed how does someone repair that ?!?!??!!
Replacement is done 99% of the time. When you hear the term "restuffing", it refers to capacitors with odd form factors. Some folks open them up and stick modern capacitors in them to retain the original appearance. You can't repair capacitors.
Now that’s some good advice. If anyone disagrees with this they deserve to suffer
Recapping is almost always a repair on old gear, where caps are certainly leaking.
Ray tells his story, Interesting, a class you can take in your neck of the woods for Stereo repair. No HS diploma as you mention, surprised again because you have a pretty good vocabulary and is 1 thing I fell shows intelligence capabilities. Install a capacitor with wrong polarity and that is pretty much a guarantee for some smoke. You look like possibly a musician and maybe was how you made a living. just my observation.
Credit the vocabulary to being a constant reader, literally from the time I learned how. Was a weekend warrior musician until I just couldn't hack the late hours while holding a day job. Always made a good living because I've always been good with technology.
Learn electronics. There are many good books and videos.
I did not realize so many unqualified people are tainting vintages boxes. That means untouched units will be harder to find. "Recap" has replaced "dial 911."
Wel, we all have to start somewhere. But that somewhere shouldn't be anything of value. There's a reason surgeons learn on cadavers.
Most of the videos on electronics repair seem to be made by older men. Are there any young men or women doing this? We need a new generation and a more diverse community of electronics repairers and hobbyists.
I couldn't agree more. These skills will die out with us old guys, unless we can interest the younger generations. I would be thrilled to find a young person to mentor. It just hasn't happened. The analytics of my channel show the vast bulk of subscribers are male (99%) and between 55-65. If you have any suggestions on how I can help attract a younger, more diverse viewership I'd be interested in hearing them.
A circuit can not function correctly if its capacitance elements are not in spec. Recapping is PART OF the process. It is not the ENTIRE diagnostic and repair process. The trick is to know if you need to replace capacitors in order to properly troubleshoot the circuit those caps are part of. You may not be able to restore a tuner to proper operation without replacing aged, worn capacitors that have developed high ESR or drifted well off value.
I have been servicing for over 50 years and this is the first video I have seen here that actually makes sense Recapping is a scam Fix it first
Jim, my beef with the whole recapping movement is that it's seen as a panacea, a cure all for anything ailing in your equipment, or it will immediately turn that sow's ear into a silk purse, especially if you use ridiculously priced magic capacitors. But the most heartbreaking aspect is those who lack experience and recap a formerly working piece of gear, and then it no longer works and maybe now emits the magic smoke. With the advent of the internet, these recapping threads/videos spread with the speed of light.