Carvin SX100 DSP, a mystery even Carvin couldn't solve...

[Libertylover]

Hello All,

Have an old Carvin i bought circa 2000. Its been back to Carvin twice for the same problem. It was never fixed.

Carvin Sx100 DSP 1-12"


(2-12" pictured)




Description of the problem;
extreme signal drop/popping
loss of tone
affects both channels
will sometimes "pop" very loudly and begin working correctly for a few minutes
sometimes pops will blow the fuses
All of the pots operate smoothly and without scratching
volume pots almost have no impact on ouput on either channel
total output with everything on 10 is maybe 5-10%
both input jacks produce same effect
problem renders amplifier unusable for any practical purpose (excepting its use as a table)


Any help would be greatly appreciated and it might end a decade old mystery. This amp was purchased with my now deceased guitar mentor during an awesome day on Sunset strip. Needless to say, it is very sentimental.

If any further information is wanting, please do not hesitate to ask.

Thank you all in advance for your help

Christopher

Richmond VA area



I believe the amps schematics can be found here http://carvinimages.com/schematics/SX100H-DSP.pdf

[xtian]

Sounds like it's time to gut that chassis and build a new amp circuit inside.

[glebert]

What did Carvin say about it? Was it fixed for a while and then failed again, or just returned it still broken?

The schematic you posted is just for the DSP section. Probably won't help for this fix.

Does this one have an effects loop? I know on some the SX100 didn't but the SX200 did.

[Enzo]

Or did it come back with "no problem found" on it?

[Gtrplr66]

Carvin amp popping sounds

I have several carvin amps. I think they sourced cheap pots for them. I’ve had to replace several. Be careful to use a controlled temperature solder gun as too much heat will lift the foils. Best to have a solder sucker to get the old one out. Good luck. I think Mojotone.com has the pots.

[drewl]

I've seen several Carvin amps with the same problem and it is usually a bad pc board connection(s) or tube socket connection.

You're going to have to let it run for a while until it craps out then trace the signal or voltages through the amp to find out where the problem is.