I'm replacing all of the electrolytic capacitors in my JVC receiver that I've had for over 24 years. There are a lot of them, 134 I think. I bought the parts from Mouser Electronics. I cannot say enough good about them. The prices were good. They shipped fast. Order seems accurate so far. It was packed real nice. All of the different values were sorted by part number. I figured they would be all thrown in a plastic bag for me to sort out. Hopefully it will restore the sound back to the way it sounded when new. It still worked OK, but the sound was a little distorted. I've read about people having good results re-capping older receivers and amps saying that they couldn't believe the difference in sound quality. Then there were some that said they couldn't tell the difference. At least it should be more reliable since the old caps were ticking time bombs.
> I'm replacing all of the electrolytic capacitors in my JVC receiver that I've had > for over 24 years. There are a lot of them, 134 I think. I bought the parts from > Mouser Electronics. I cannot say enough good about them. The prices were good. They > shipped fast. Order seems accurate so far. It was packed real nice. All of the > different values were sorted by part number. I figured they would be all thrown in a > plastic bag for me to sort out. Hopefully it will restore the sound back to the way > it sounded when new. It still worked OK, but the sound was a little distorted. I've > read about people having good results re-capping older receivers and amps saying that > they couldn't believe the difference in sound quality. Then there were some that said > they couldn't tell the difference. At least it should be more reliable since the old > caps were ticking time bombs. > > Italie, > > This seems like something up your alley.
I've done several commercial / professional grade amplifiers, but never had the inkling to do a receiver 100%. There are too many damned caps... . Really hard to troubleshoot as well due to all the ancillary crap crammed in there.
Cap kit would make a difference, if they were bad. If you don't notice any improvement sometimes resistors get burnt, solder joints get cracked, transistors go bad....
If you've got the desire to do every cap, power to you, it can't hurt.
I'd have to agree that it's worth a shot if you can get through it all. I've never done a receiver, but I have recapped a PC motherboard that had failed because it had cheap ass caps that started leaking. Worked just fine afterward.
There are a few that are bulging and a few that leaked a little electrolyte. I was surprised the the two main 10,000uF caps were slightly bulging. Those two bastards were $13.68 each! The rest were pennies. I haven't run across any burned resistors yet. A few solder connections that looked a little crappy looking, so I hit them. I just hope it all works when I get it done! Lots of ribbon cables snaking back and forth. I finished the power supply and amp so far. Tomorrow will be the pre-amp section, and maybe the front panel.
> There are a few that are bulging and a few that leaked a little electrolyte. I was > surprised the the two main 10,000uF caps were slightly bulging. Those two bastards > were $13.68 each! The rest were pennies. I haven't run across any burned resistors > yet. A few solder connections that looked a little crappy looking, so I hit them. I > just hope it all works when I get it done! Lots of ribbon cables snaking back and > forth. I finished the power supply and amp so far. Tomorrow will be the pre-amp > section, and maybe the front panel.
If you have leakers, capping it will help. No electrolyte = not doing its job.
The big guys often have a "domed" look from the factory depending on what type they are. (solid smooth top?) If you are in there already and don't mind the $26 bucks it isn't a bad idea to switch them out though.
I'd personally skip the front panel just out of laziness if you aren't having issues with it...but that's just me. (I'd probably be taking it apart again in a week when the display went dead too.)
> I don't think they were originally domed. It's kind of hard to see but...
I'm not going to say they aren't bad, but the big ones don't tend to boil quite like the little ones do. The one on the left looks a little worse for wear, but the one on the right is pretty close to what I'd call "factory". (Not that a clean looking cap is any indication of it's operational status...)
> I don't think they were originally domed. It's kind of hard to see but...
I'd most definitely say the left one is past its use-by date. With caps, if you have any doubts, replace them. Notice how those caps say 85 degrees C... better ones will say 105 C, and will last longer.
My stereo (its just an amp, no radio), was purchased in 1977 and still sounds fine to my aging ears.
The ones I bought to replace those two are 10000uF 80V @ 105° C. All of the rest are Nichicon KW series audio capacitors. They are rated at 85° C like the originals. I originally had chosen 105° C caps but ended up changing my mind and went with audio grade. There are so many different kinds of electrolytic capacitors for the same value, even from the same manufacturer. Too many choices, very confusing.
Robbbert,
What brand of amp do you have? Pioneer, Sansui? That kicks ass that it still sounds good after 34 years!
> Robbbert, > > What brand of amp do you have? Pioneer, Sansui? That kicks ass that it still sounds > good after 34 years!
Er, actually it's a Tandy Realistic brand (=Radio Shack in other countries). It's been a fantastic amp over all these years. Still have the original Tandy speakers as well.
Well, 135 caps later and to my amazement she WORKS! So far it definitely sounds better. The sound was a little smeared before for lack of a better way of describing it. I have only tried my Sennheiser headphones with my Sansa Fuse playing through it. I forgot to buy wire ties to hold all of the ribbon cables together so I probably won't connect it to speakers until tomorrow.
I did have a little scare when I first tried to power it up. It wouldn't come on. What a shitty feeling. I thought I was gonna puke. Then I started messing with the buttons on the front panel and the balance control was stuck down. I loosened a couple of screws and she came on! I guess it is some kind of matrix thing where the stuck balance control was blocking the power switch. By the way it is "computer controlled", so no potentiometers.
I threw out something of that vintage 2 months ago. A Superscope R340 I think it was, quadraphonic (4 speaker). The amp had an AM/FM tuner in it with a pink light, but the tuner knob didn't work (the pulley string was broken) unless you took it apart and manually tuned it*. The amp had a constant 50Hz AC buzz all the time, and the right speaker used to cut out after about 30 minutes of use, turning into a farting type noise. It was probably just old capacitors, but I had half a dozen amps at the time, so I just swapped it and threw it out on the nature strip with other electrical goods (broken air conditioners, TVs etc).
The replacement amp ended up being a Sharp SM-1122.
* Being Melbourne, all of the radio stations are utter crap anyway, shitty 90s+ pop/teen songs (Britney Spears, Bieber, wannabe rappers etc), generic rock (Coldplay, Matchbox 20, Cold Chisel *zomg BARNESEY~!!!!!111* etc), 50s/60s/70s hits, druggie music/trance/progressive/emo rock etc on Triple J and of course classical and oldies and talk radio on AM - to someone who grew up listening to Metallica, Pantera and Slayer, most of the radio stations are just crap. Nothing better than playing Vice City, shooting people with rockets in an army chopper whilst Raining Blood is playing in the background on VROCK!
Man, if that was a Marantz, you shouldn't have pitched it. Someone would have bought it from you. I don't know that much about Marantz, but know they are highly sought after.
My receiver turned to shit. I was just about to put the cover on but I wanted to adjust the idling current closer to the specified 5 mV (it was around 7 mV). My meter doesn't have alligator clips on it so I asked my 15 year old daughter to turn the variable resistor while I held the test leads on the emitter resistor (test point). I'm not sure what happened but I saw the meter say something around 20 mV and climbing. Right when I told her she was going the wrong way - POW. The fuse blew. We both jumped because it lit up like the 4th of July (just the fuse, not the whole thing). I asked her what happened, did you slip off with the screwdriver and hit something? "I don't know." Anyway, the variable resistor was all of the way up against the stop, so I'm not sure what happened. Unfortunately, it caused two of the main power transistors to short. I hope that is all. The transistors that drive those two seem to be OK. Now I have to locate some expensive transistors.
Too bad too I really wanted to hear this thing through speakers. It sure sounded good in my headphones.
Stay 'tuned', I'll post back when I get my hands on a couple of transistors and a fuse.
> * Being Melbourne, all of the radio stations are utter > crap anyway, shitty 80s+ generic rock/metal/druggie > music/grunge/emo/guitar-centric bands and oldies > to someone who grew up listening to Metallica, Pantera and > Slayer, therefore most of the radio stations are just > right! (crap).
About Australian music... Since I'm in the states, I haven't been exposed to a whole lot besides the overplayed AC-DC. I only learned of Cold Chisel recently and for the life of cannot understand why their music was never played here. We have had some Jimmy Barnes played here. Good stuff. Too bad your station overplays it.
I especially LOVE this Cold Chisel song...
A few others that I like..
Tarney / Spencer Band Real Life Little River Band Crowded House The Sherbs Billy Thorpe (Can you get me a real Children of the Sun CD, not the best of?)
This stuff doesn't get over played here. LRB was a little heavy for a while, not so much now.
Well, I got my transistors put in tonight and set the idling voltage to the specified 5mV. I connected her up to my speakers and it works and sounds great. A definite improvement in sound. To me, it sounds like it did when it was new. Of course, it is hard to remember 24 years ago, but I think it is close to the original sound. Also gone are the random small clicks and the background noise is quieter too. All in all, I'm pleased with the results. I won't let my daughter help me with adjusting something of this nature again! That was a damned expensive pop. $38 for those two transistors. I highly recommend this kind of project to someone who has older equipment and can follow a diagram and can solder.
Index 
Threaded 
Anyone here ever re-capped a stereo receiver?
Reply
[Re: 
. Really hard to troubleshoot as well due to all the ancillary crap crammed in there.
