Yamaha C-45 recap

Sam Cogley

Last of the Time Lords
Subscriber
I've recently started evaluating the restoration work needed on my Yamaha C-45 preamp in a renewed effort to get some projects finished. One thing I've noticed about it is that Yamaha used some interesting (and not cheap) cap selections - black and gold Nichicon audio grade caps in most places, with Nichicon Muse caps in the phono section. I found this to be a bit surprising for the low end of the 45/65/85 model line.

Any suggestions on which current electrolytic caps are best to use in each of the different positions? Is there anything else that needs to be done to it outside of the standard recap?
 
There are rubicon "blackgates" in those power amps as well. ie. 45/65/85..
 
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Being the Yamaha tech guru, do you have any suggestions on which current production caps to use as replacements for each of the specific types used in the C-45?
 
Being the Yamaha tech guru, do you have any suggestions on which current production caps to use as replacements for each of the specific types used in the C-45?

Non-polars use Nichicon ES from Mouser.
I'd probably go with Nichicon KZ and FG for the rest.
For the big ones, KG's or KS's if they will physically fit.
KS's have a lower profile.
Mouser carries both.

*Note: KS and KG are snap-in style leads.
 
Ah, gotcha. I'll get a cap list made up and start ordering parts.

The power switch is still fritzed. It's "on" no matter what position it's in.
 
I've recently started evaluating the restoration work needed on my Yamaha C-45 preamp in a renewed effort to get some projects finished. One thing I've noticed about it is that Yamaha used some interesting (and not cheap) cap selections - black and gold Nichicon audio grade caps in most places, with Nichicon Muse caps in the phono section. I found this to be a bit surprising for the low end of the 45/65/85 model line.

Hmmm. Perhaps that's part of the reason I've been perfectly happy with my 'low end' C-45? And all this time I thought maybe I had a tin ear or something...
 
I've got four MX-1000U's in one room, two MX-800U's in another, and two MX-600U's in another. One thing I've been rather surprised by is that the character and quality of sound among the whole lot is indistiguishable one to the next. I bought the first 1000U new and all the others after a 30-year test period, to be sure that's what I wanted. :D I remain convinced Yamaha's commitment is to quality first, in everything. If you buy up the chain, you get more features, but down the chain, no lesser quality.
 
Hmmm. Perhaps that's part of the reason I've been perfectly happy with my 'low end' C-45? And all this time I thought maybe I had a tin ear or something...

I only meant "low end" in that it's the bottom model of that line. Seems to be an exceptionally well-built unit, no matter where it fell in the hierarchy.
 
I've been trying to get the C-45 running right to make sure I don't need to order anything like replacement semiconductors when I order the caps. After rebuilding the power switch, thoroughly DeoxITing the balance, loudness and volume pots, and re-soldering all of the input jacks and the balance and loudness pots, I'm happy to report that it's working well. This thing has literally been through hell and back, yet it keeps on ticking.
 
VD-1212 info for Avionic

Hello Avionic
I think you was looking for serious data about VD-1212 diode in YAMAHA C4
Here is a document that you never find anywhere:nono:
hope this help !:thmbsp:
 
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Interesting...this unit has been sounding great, but apparently some AC is getting onto the outputs! An RCA cable plugged into the "video" input buzzed me a bit a few nights ago, and a Scott 330D that was plugged into it developed a mild hot chassis situation. The Scott is fine if plugged in but not connected to the Yamaha. Any thoughts?
 
I wasn't aware of video inputs on the C-45..:scratch2: Yep. by gosh there is a video jack..
 
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Interesting...this unit has been sounding great, but apparently some AC is getting onto the outputs! An RCA cable plugged into the "video" input buzzed me a bit a few nights ago, and a Scott 330D that was plugged into it developed a mild hot chassis situation. The Scott is fine if plugged in but not connected to the Yamaha. Any thoughts?

Did you try flipping the AC power cord 180 degrees?
 
No, I didn't think to do that before I pulled it out of the system. I looked over the schematic and didn't see a "death cap" to ground from the AC input, which left me feeling even more puzzled as to how it's getting enough AC onto the input jacks to buzz me.
 
Transformer leakage,AC power switch leakage,pinched/chaffed wires-fasteners to long..:scratch2:
 
I said "outputs" earlier, I meant "inputs." It was the center pin of one of the Video inputs that buzzed me.

The Quintessence preamp is back out, I've got a few other things to tinker with, then I'll pull the cover on the Yamaha to make a cap list and see if I can figure out what's wrong with it.
 
I said "outputs" earlier, I meant "inputs." It was the center pin of one of the Video inputs that buzzed me.

The Quintessence preamp is back out, I've got a few other things to tinker with, then I'll pull the cover on the Yamaha to make a cap list and see if I can figure out what's wrong with it.

Just pack it in a box and ship it to Ft.Dodge.I have just the amp to use with it.:D
 
Another late update...I recapped this thing and then got busy, the recapped boards sat around for about a year or so before I finally got around to reassembling everything. Seems to be working fine, and sounds great.
 
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