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CA-810... with some pics

Thanks Billy! :thmbsp:

The CA-810 is indeed a beautiful amp. I had it "dead" (no sound, broken lamps and other issues) and decided start the restoration anyway. I know the main rule is "fix it first, then recap it", but I had few time then and was really curious to listen to it with everything finished.

I could also replace most semiconductors (Zeners, trannies, ect) as these are fault prone at this time of their lives, but after checking them, I decided to concentrate more on the caps and on a deep cleaning of parts and contacts, wiring. If I ever found another CA-810, this time will be big fun! :yes:

For the pictures, my main tool is always the little Olympus attached on its mini tripod and various/combined sources of light: flash, available light, a torch, some panel reflectors, etc. A mini studio was set for thess pictures. It is fun, too.

2ighydx.jpg


Regards,

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I like using an improvised mini photo studio for these amps. Just recapped two Denons and took a few pics of then as well, but due to new Imageshack picture policies ($$), I haven't published that much...

6i7f2s.jpg


r8yvd0.jpg


http://audiokarma.org/forums/showpost.php?p=7866525&postcount=9

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I have one that I'll be working on soon, so thanks for the pics. I'll be taking mine also. Anyway, vr402 (the one you get from the side). Is it better to just replace with a multi turn you get at from the top like the left side, or was there some other reason for it? I'm away from mine right now, so I can't really picture whether on of the boards or switch shafts were in the way for setting bias.
 
jheu02 said:
I have one that I'll be working on soon, so thanks for the pics. I'll be taking mine also. Anyway, vr402 (the one you get from the side). Is it better to just replace with a multi turn you get at from the top like the left side, or was there some other reason for it? I'm away from mine right now, so I can't really picture whether on of the boards or switch shafts were in the way for setting bias.
Click to expand...

Hi,

I finished to buy two multi turn "YB" trimpots (adjustable from top) when I had the power board out to work on. And realized they were different only when I reassembled back the parts.
So in the CA-810 the left one is "YB" (top adjustable) and the right is "XB" (lateral adjust.). I'm not sure about the CA-1010 or 2010 models.

I managed to set bias with the input board basket off that rail fixed by a screw. But yes it's better to buy a "XB" pot for the right channel.
 
2SC734 (Y) - possible replacement

I had a couple of messages asking a possible replacement for that transistor with the Y mark on top and present in a few amps - Marantz, Sansui and Yamaha of same time (late 70s).

It's a 2SC734 - NPN (Vceo 70V - Ic 150mA - Pc 0.3W) and the replacement
can the BC639 - NPN (Vceo 80V - Ic 1A - Pc 1W).

1r83eb.jpg
 
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Karl vd Berg said:
Hi,

I finished to buy two multi turn "YB" trimpots (adjustable from top) when I had the power board out to work on. And realized they were different only when I reassembled back the parts.
So in the CA-810 the left one is "YB" (top adjustable) and the right is "XB" (lateral adjust.). I'm not sure about the CA-1010 or 2010 models.

I managed to set bias with the input board basket off that rail fixed by a screw. But yes it's better to buy a "XB" pot for the right channel.
Click to expand...

Thanks. I'll order the correct one then.

edit Looks like mouser only stocks the vertical trimmers in the 2.2K value. Looks like I'll end up having to bend the leads and extend them so the set screw is accessible.

Edit 2. Going over the data sheets, it looks like the "P" designation is the standard for horizontal trimmers. I found some in 2K vs 2.2K, so hope that's close enough. 2.5K would probably be a better option if I can find them.
 
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You can use either 2K or 2.5K (original value 2.2K)

I used the 2K value and, as multi turn trimmer, the 2K is actually a bit more precise than 2.2K

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From the Web a cut Bourns:

23r7a77.jpg
 
I decided to go with Murata 25 turn trimmers. The P designation does indeed designate the side-mounted type as shown on the datasheet link. I still may need to extend the leads so that the adjustment screw will be high enough to reach.
 
jheu02 said:
I decided to go with Murata 25 turn trimmers. The P designation does indeed designate the side-mounted type as shown on the datasheet link. I still may need to extend the leads so that the adjustment screw will be high enough to reach.
Click to expand...

Nice!

Yes, make sure the side-mounted adjusting screw faces towards the lateral hole at right side...

2v15efb.jpg
 
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Hey, sorry for reviving an old thread. However, the pictures are dead, and they'd be a great help in disassembly of my newly acquired CA-810. Would anyone still have them by any chance? Or could point me to a similar resource?
 
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