2. amps-preamps
  3. 1102039565

Anyone know the Yamaha CA2000 Amp?

Hi,

I just bought a vintage Yamaha CA2000 amp and am very impressed with it (got some NS100m speakers with it which are very tight if lacking in the very low frequencies.)

Two questions. When I change the switch from "Normal" to "Class A" the sound starts to break up. This is probably a fault but is it worth fixing? What would I get if the class A was working? At the back there is a "DC"/"Normal" switch which seems to make no difference when I change it. What is it for?

Any suggestions for a small subwoofer for the NS100M speakers? I don't want to lose the lovely precise sound but I do miss the fuller lows of my old bass reflex speakers.

Thanks a bunch! Derek
derekw5701
derekw5701 OP
3 posts
 
The problem is when I switch it to Class A the sound slowly starts breaking up until it is just a weak, crackling noise.

From that manual I gathered that the DC switch is to allow you to bypass the DC speaker protection if you are using the power amp directly (without the preamp.)

Sounds like the class A difference may be almost inaudible to most people.
loontoon
301 posts
 
I don't know the amp but I do know the symptoms, on rare occaisions it can be caused by a dirty volume pot, but due to the nature of it only occuring in class A, I would suspect due to the high bias current/voltage, MOS/Tran that the coupling caps if they are there are going, or the main power supply caps could sag and cause the same problem.

I can't speak to the amp and tell you to repair it or dump it.

loon
derekw5701 OP
3 posts
 
Thanks a bunch Loon, I'll try to get it looked at as it may be worth having the class A working. cheers, derek
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