Toasted Pre

I have a 220V amplifier (Krell 2250) connected to a 110V pre (Acuphase C2000) and after an year of faithful service the right balanced output from the pre toasted!

I’ve attached some photos of the board so you can see the problem I have here.

It seems I should not have mixed 220V with 110V in the same system.

The technician says it can fixed with parts he can find here but I thought of asking the more experienced...

I don't know how it ever worked at all! I assume your current is 220, I was once supplied a 220 amp by a British company who didn't know the US voltage was 110 and it would not play. So apparently you have been feeding 220 volts into a preamp that was designed for 110. If this is the case it is a testament to its quality. I am still having a hard time understanding how it functioned for a year. What is your wall current?
I'm not sure I understand. Was the line voltage 110v or 220v? Were you using the correct step up/down transformer on the power line to which ever component didn't match the line voltage?

As long as both the pre and power amp each saw their specified voltages you shouldn't have a problem.

Please clarify.
Stanwal, Ghostrider45,

It seems I should not have mixed 220V with 110V in the same system.

Gabriel_37 profile says he lives in the USA. I believe he has a 240V power receptacle outlet for the amp and a 120V power receptacle outlet for the preamp.

That in itself would not cause the preamp problem. Might cause a slight buzz but not any damage, imo....

Looking at the pictures it almost looks like something like pop was spilled on the top and ran through the vent holes and caused electrical components and traces to arc and short out. Sure is a lot of black carbon around the burnt area in the pictures.

Either that or one hell of a lightning strike hit the preamp. If that were the case though I would think other audio equipment would have been damaged as well.

Or it could of just been an electrical component short out arc across and the rest is history....
Dear all,

I live in Brazil and voltage here in São Paulo is 110 volts.
The pre that toasted (an Accuphase C2000) is 110V and was plugged to the wall in a correspondent outlet. Or, better saying, connect to a PS Audio Outlet and this to the wall. The amp I use is a Krell 2250 which is 220V and is plugged to a 220 Volts outlet without any further protection (the 220V outlet was installed by an electrician I hired since the Krell representative told to wait three week to find if they could change the voltage for me...)

Looking inside the pre there is a like a "mother board" and some four cards are vertically plugged to this, and one of them pzzzzit.

I did not test, might be that the single ended RCA outputs are working nicely.

Anyway, I think I'll find a way to convert the amp to 110V also, before more damage is done.

So much for AGon's history.....

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The preamp did not short out because the amp is fed from 220V and the preamp from 120V, jmho.

You can check the archives here on Agon and AA and find others that have or do the same now. Albert Porter for one, did at one time.
DO NOT plug the pre back in.....until fixed properly. That board is TOAST.
And, since I see that chip is cracked in half (!!) I'll have to say it was Really Really hot before failure.

Since you had the proper voltages to each piece, I don't think that was the problem.

I don't believe the board can be salvaged.
Jea48, Magfan - I concur.

I like the lightning theory.....


The technician is working, let's wait and see, and hear.
I'm sure he will fix it, not sure what will come out of the pre again...

Meanwhile using a Benchmark DAC as pre.

Thanks for inputs

I learned from the tech that one of the balanced channels was toasted, the other one is fine, and since the boards are separated and equal, he carefully one was guide to fix the other.

Let's see