Amplifer 1 channel dead .Please help

[Pass lover]

Hi, I think there may be sonmeone could help.

My Carver TFM 15CB has 1 channel dead

The TFM15CB has built-in passive preamp (which I believe it can be bypassed ). When having jumped the signal( routing the signal directly from input socket to the amp CB), I forgot to turn down the CD player output level. The result is the sound is VERY loud. I had to stop the CD player immediately.

When I jumped back the signal route as original, there is no sound on BOTH amp channels. Leaving it for about 3 hour ( still in original state), turn it on, there is only ONE channel work ( the LEFT one)

I don’t know what happen to the power section. I think the too- loud signal hurt something in the CB

Dose anyone encounte this problem before?

I still have a nother Carver with the same model ready for mono bridged. What should I check?

Please give your advice
http://i24.photobucket.com/albums/c4...eandPower1.jpg

http://i24.photobucket.com/albums/c4...em/Inside2.jpg

[Pass lover]

Hi

May be no one could help.

It makes me more confused when I mono bridge the amp, it works perfectly.No problem at all



Please help

[jaycee]

Looks like the preamp is just pots, so it's probably just a bad pot on that channel... when bridged the signal only goes by the working channel and it's OK.

Without seeing a schematic it's tough to be sure

[orbanp]

First thing is to find the schematics for your amp. Looks like this web site has it: http://www.thecarversite.com/manuals.htm
Once you have the schematics and post it somewhere to be available then I am sure that many members on this forum could help you.

Good luck, Peter

[Pass lover]

Originally Posted by jaycee

Looks like the preamp is just pots, so it's probably just a bad pot on that channel... when bridged the signal only goes by the working channel and it's OK.

Without seeing a schematic it's tough to be sure

Thanks for your idea. But as I said it worked perfectly, it is true. I have a nother amp ( the same model: TFM15CB). Having made a blind test in bridged model, I found that the 'problem' amp sounded even a bit louder than the normal one. That made me confused

I also found the website address to down load the schematic. But it is a bit difficult to read due to poor copy quality. I still tried to find the way to post it on.

the schematic was downloaded from www.thecarversite.com after registering

[jleaman]

have you taken the board out that holds the 2 pot ? Maybe give them a quick solder job ? They are probably used lots ( ie turned up and down ) so a cold solder could effect this.

J'

[Pass lover]

Originally Posted by jleaman

have you taken the board out that holds the 2 pot ? Maybe give them a quick solder job ? They are probably used lots ( ie turned up and down ) so a cold solder could effect this.

J'

Hi, I did check the preamp board. It is working. Now I have just bought a preamp, plug it directly to the amp, still 1 channel sound. I think the power section has problem

However, it made me mad when mono bridge the amp, it still sound percfectly

[jleaman]

Originally Posted by Pass lover

Hi, I did check the preamp board. It is working. Now I have just bought a preamp, plug it directly to the amp, still 1 channel sound. I think the power section has problem

However, it made me mad when mono bridge the amp, it still sound percfectly

If one channel is not working then when you bridge it, there will be no difference.

I'll ask some questions,

So both channels actually work ?

when you change the cable from the front board a to be or b to a, vice versa they both work when testing them ? with the good one..


?

Jase

[Pass lover]

Originally Posted by jleaman

If one channel is not working then when you bridge it, there will be no difference.

I'll ask some questions,

So both channels actually work ?

when you change the cable from the front board a to be or b to a, vice versa they both work when testing them ? with the good one..?

Jase

Hi Jase

A test was made with the good amp ( plug B to A vice versa). The good amp work perfectly in stereo and in bridge mode).

When being bridged, ( both amps are in original condition. That means thers is no mod here: the cable B in B position, and cable A in A ...no change at all) I can say that the good and the 'problem' amp sound identically. The 'problem' amp sound abit lounder than the good ( but not significantly)

That is why it made me confused

In theory, the 'problem' amp must sound less lound than the good due to having 1 channel dead

[jleaman]

totally lost now.