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CR 620 Doesn't Sound Too Good

I've recapped my Yamaha CR-620 some time ago, and I can really -really- recommend it. The caps on the tone board were way out of spec, dried out, or even bulging out.. Even with no adjustment to sound, the tone board is being used. A lot of those electrolytics can be replaced with modern film/foil caps. Also, the power supply caps need to be replaced. Mine weren't at even half capacity anymore.. If you recap it yourself, it'll set you back $40 dollars or so. Depends on what quality parts you pick :)
 
So many are finding out that it really pays to update the caps on these boards from the 80's.
Face it, the chem is old technology, it is dried out and there is a 30+ year research and advance technology to the new caps.
 
I'd like to have someone recap it for me. Trouble is, today I can't seem to get any sound out of it any more.

If it was recapped I'd bet I'd like the sound of it a lot better.
As it is, it has a piercing treble that almost hurts my ears.
 
Can anyone tell me what I might do to test why my CR 620 will not make sound?

Otherwise I'm going to take it to a shop one of these days.

My little CR 400 sounds 3x better than this CR 620.
 
Lukey said:
I'd like to have someone recap it for me. Trouble is, today I can't seem to get any sound out of it any more.

If it was recapped I'd bet I'd like the sound of it a lot better.
As it is, it has a piercing treble that almost hurts my ears.
Click to expand...

Where on terra firma are you located ? :D
 
I'm in East Tennessee.

There's a vintage audio repair place in Asheville NC which is 1 hour South of here.

There's another guy that works on them locally but he's way too slow and he smokes and I don't want to get it back smelling like cigarettes after my unit hangs around his smokey house for 3-4 weeks. :) He and his wife and family are heavy smokers and for this reason I'd really rather not deal with him.

I have a feeling I might be able to recap it myself. I have my own DMM, soldering iron, de-solderer, etc., and have relamped receivers and done some testing with the DMM.
I'd need some people to help me though, at least some.

My little CR 400 receiver is by far the best sounding receiver in the house. Yesterday I moved it back into the living room and hooked it up to my Paradigm Phantom speakers and Yamaha CDP 480 and it sounds very, very nice to my ears. The CR 400 is too good for the bedroom, IMHO. I need to have it in the LR so I can hear that rich sound more often.
My SX 780 sounds nice but nowhere near as nice as my little 16 WPC CR 400.

I'm thinking that I'll appreciate my CR 620 a lot more after it's recapped.
 
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Lukey said:
I acquired a nice clean looking Yamaha CR 620 [35 wpc] receiver for about $40 but my CR 400 [16 wpc] sounds much better. Why is this?

The man I got it from said he cleaned it with GC Wash and Deox'd it all. Why then doesn't it seem to sound too great?

I can solder in new lamps but I never recapped and I have no electrical knowledge to speak of.
I have a DMM.

The 16 WPC CR 400 seems to have as much or more power than the CR 620.

The tuner in the CR 620 doesn't pull in stations well, and the phono section seems lacking.
The tuner in my CR 400 pulls in stations really well.
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Lets start by.. Verifying power supply voltages. How are you at reading a schematic?
 
Probably not too good at it.

I have an account at hifiengine.com and can get things there.

I adjusted the amplifier board on the CR 620.
 
On page 15 of the service manual it shows the power supply/main amplifier CCA. On the left hand edge are 4 pins marked +12,+12,-12 and what looks like +30. With your meter set on the VDC and the black test lead fastened to metal chassis ground. With the red test lead . Probe the 4 pins mentioned above for the voltages mentioned. Be careful not to short out adjacent pins with your meters test probe.
 
OK, thanks again. I will try to get to this soon.
Please check back in a few days and I hopefully will have gotten to it by then.
 
I really appreciate the advice but I don't think I'm going to be able to operate on this CR 620. While taking the cover off it, I broke the FM tuning string and now I really need to get it to a audio shop.
 
PS -

I may get this CR 620 restored by an audio shop. If I do, chances are it will then sound as good as my older CR 400, is that right? If not I'm going to sell it and get another vintage Yamaha like a CR 400, 600, or 800.

I never liked the sound of this CR 620 very much, possibly because it needs recapping.
 
You do know that there is a dialcord stringing drawing in the service manual. Just say'n.:scratch2:
 
If you don't like it now, I cannot recommend spending any real amount of money on it. In my experience, recapping usually doesn't do a whole lot - if anything - to the performance. I recap everything I have, but that's mostly for reliability/restoration purposes, not the sound. If you like your CR-400 so much, why even get another amp in the first place? :music: Have that recapped instead, that way it'll probably live well for a long time.
 
avionic said:
You do know that there is a dialcord stringing drawing in the service manual. Just say'n.:scratch2:
Click to expand...

It's all strung up, the string just broke near where it connects to one side of the dial pointer. I may be able to get them tied together again or get that end connected to the pointer.
 
Baron K Rool said:
If you don't like it now, I cannot recommend spending any real amount of money on it. In my experience, recapping usually doesn't do a whole lot - if anything - to the performance. I recap everything I have, but that's mostly for reliability/restoration purposes, not the sound. If you like your CR-400 so much, why even get another amp in the first place? :music: Have that recapped instead, that way it'll probably live well for a long time.
Click to expand...

I had a feeling the CR 620 might sound the same if it's brought up to spec by recapping it, etc.
The CR 620 is too bright for my tastes. I like my Pioneer SX 780 better than the CR 620, it's warmer and more powerful.

I have 5 receivers and 2 of them don't work.
I have 6 CD players, a TT, and 5 pairs of speakers, all working.

I don't need more gear but I feel like buying more because I'm not getting enough pleasure out of life and I have nothing better to do.
I have an ex boss that's very controlling and determined to destroy my health and life any way he can, and it's very depressing.
I have no friends and I feel like the end of my life may be near.

I sold my motorcycle a few months ago and I have a few hundred to spend. I may buy a nice restored Sansui for $200 or $300.
I may also have my CR 400 and/or SX 780 recapped.

I swapped gear with a collector guy, but the trouble is, his gear isn't fully tested. He buys it just for something to do and stockpiles it in his audio room and then sells a half dozen units at a time when he needs the space. He often doesn't give his gear the test of time. He just hooks it up and powers it on, and then lets it collect dust.
It may seem like a sweet deal but it's a crap shoot as to it's longevity.
 
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Maybe try learning how to restore audio gear yourself, in that case. It's a nice hobby, and very time consuming (at least if you end up liking it).

Why do you let your ex-boss control you? Seems like a good idea to cut them out of your life. It's easier to lose people than find new ones, I think. :scratch2:
 
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