Carver amp part info needed

[llwhtt]

Is that a 2SD2012? You never stated if the amp was dead or not. Does that amp have lights on the front panel? There is a circuit for controlling brightness, that shouldn't affect the operation unless it is causing problems with the +31VDC line. Anyway no such parts of that number or value in the TFM-45, I tried.

Craig

[KyferEz]

No, its a 2sc2012. It does have lights, but they haven't been working since before the amp died.

Yes, the amp is dead. I'm guessing from your statement and what I just said about the lights, that maybe this isn't the reason the amp is dead...

The meters used to surge when turned on, now they don't, and it has no audio output. Before it died, it sometimes wouldn't work when I turned it on and I'd have to turn it off and on again.

[llwhtt]

Originally that transistor was 2S02012 on your post, wasn't it. My eyeballs are getting bad but not that bad, please tell me it was. There are two transistors in the light circuit, the TO92 case and a much larger one, 2N3055 in the 45. The large xsistor does the actual work of dimming, it is tied to the +31VDC line directly and may be bad also. Maybe you can't tell by looking at it.

Craig

[KyferEz]

Yes, it was originally a 2s0, in the post I said I had edited it to fix the p/n

This transistor is a to220 package with a heatsink. I'm going to need a substitute. I can't even find the datasheet for it.

Thanks!

[llwhtt]

2SC2012 is supposed to be a TO92, 2SD2012 is a TO220. See if the person that gave you that info can get you the schematic. Something is not correct. Can you tell where the resistor is connected?

Craig

[brighammirabell]

Hello,
Sorry to jump in the middle here but seems like a good thread for this type of question.

I am looking for some ideas for my Carver C-2 Preamp. It has a low hum out of the right channel on all sources (loudest on MC phono Input) with the volume off and gets increasingly louder with turning up. And in both channels a buzz.

I have replaced all radial capacitors with new audio grade Nichicon. And deOxiT'ed all switches and knobs. However i still get a loud pop out of both speakers when i press power switch or mute button on and off.

Balance knob has no effect on the noise generated on either channel, left or right the hum & buzz is constant. All this with no other sources plugged in - just decent interconnects running to A carver Model M-0.05t that preforms flawlessly with any other preamp hooked to it.

I read up on ground loop issues and tried most suggestions for additional grounding but non worked and it didn't make sense that the hum was only out of one channel and I could swap L& R channel and get hum out of other speaker. Also inspected for cold solder joints while i was replacing caps but didn't see anything that looked out of the ordinary.


Please if you have any ideas I am handy with a multimeter and am ready to replace any other components you can think of even if its a longshot. Thanks in advance.