Is that smoke from my Krell KSA 100S?

[Bryan]

So, I turned on my Krell KSA-100S, and before the relay's kicked in, I shut it off accidentally when trying to hit the display button.

I then turned on the power again, and PUFF/SNAP/SMOKE!

The circuit on my power strip blew, and nothing else was damaged.

I am good with tube circuitry, but know very little about solid state.

Any suggestions where to start? I am going to go buy a torx bit so I can open her up, and look for the burnt components, but if anyone has any ideas where to look first, it may save me some time.

I'll report back when I open up the lid.

Thanks,

Bryan

 

[Brian Donaldson]

I'm not versed on Krell innards, but I would suspect that you turned it of and back on before some type of sort start circuit reset itself and the inrush burned something. But that's just a wild assed guss.

 

[Bryan]

Yeah, I was thinking the same myself....

I opened her up, but can not find any obviously burnt component....

Hmmm.........

 

[SY]

First two things I'd check are fuses and rectifiers.

 

[mb]

I've owned a 100S for a number of years, and have had two caps blow on me. The PUFF/SNAP/SMOKE part sounds familiar. You may want to sniff out the caps. As a precaution, my dealer eventually changed the full set of main caps. That was two years back.

 

[hacknet]

ive done it to my krell ksa150 too. the sparks and flames lasted quite awhile... i was stunned. i just sent it for repairs... did ask questions at that time.. what a waste.

 

[EchoWars]

Why a waste??

...just curious...🙂

 

[ChocoHolic]

if you did not find any burned component....
may be you can find burned "track fuses" on the PCB??

good luck!

 

[Bryan]

Hey Guys,

Well, after several hours of trouble shooting, I decided that I would not be able to find the problem. I think I will junk the amp, and pull out any goodies (68000uF 100V) caps for use in other projects. I paid 1500 for the amp a few years ago, and I could only imagine the cost of repairs would be near 500 with shipping and labor, and parts. (Wish it was a tube amp, as I'd have it fixed by now).

Anyway, I am curious to see what the other faults you guys have had were caused by, and at the end of the day, how much did the repair cost. Please keep me in the loop.

Best of luck,

Bryan


PS. Any suggestions for a good replacement in the 2-2.5K range?

 

[5th element]

I would not abandon it that soon, you could try and power the thing up on another low voltage power supply and see if the amp its self still works, if it does then its the PS.

Just turnin the amp on and off wont kill anything within the amplifier circuitry. it does sound PS related. If you have a simple PS simply turnin the amp on and off quickly doesnt damage anything.

I'd be wary about the PS caps mind you.

Hacknet - the sparks and flames lasted quite awhile. This sounds as if the PS caps were emptying out and "fueling" the fire so to speak, so id watch it.

 

[jewilson]

Have you check the power supply voltages? If it is not the supply it more than likely an output transistor and it's emittor resistor.

 

[sam9]

I'll keep this little story in the back of my head for the next time some helpful soul informs me that my ancient (20 year) Carver M-400 is unreliable and prone to go up in flames! a quick off-on cycle makes a thump but that's all. Twenty years of thumps, but no smoke.

 

[kilowattski]

Bryan,

Before you junk the amp please email me. Maybe we can work something out. I live out on Long Island.

Guy