Krell KSA-250

If I knew I could get away with it, I'd eliminate the "Slow Start" as designed. Maybe I'll post the Schematic and see if anybody thinks it's feasible.
 
Rev D which is what I have. Got the AC in on the left side, and the circuitry to the 60LB Toroid Transformer on the Right and the L/R+ and L/R- Sense on the bottom left. The Remote isn't even there. I have the skizmo finished in CAD but would like to come up with something a little less "CRAZY". Any IDEAS???? The 700 Ohm resistors (R1/R2) get so hot they char the board and will destroy it without intervention. It was too late for mine.
 

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Rev D which is what I have. Got the AC in on the left side, and the circuitry to the 60LB Toroid Transformer on the Right and the L/R+ and L/R- Sense on the bottom left. The Remote isn't even there. I have the skizmo finished in CAD but would like to come up with something a little less "CRAZY". Any IDEAS???? The 700 Ohm resistors (R1/R2) get so hot they char the board and will destroy it without intervention. It was too late for mine.
I don't want to give away any of my secrets to Krell :-)
 
I see the problem Perry, they need more relays :) Soft starts are complicated but not that complicated. They have a standby circuit it seems which is always alive.


I looked at it while I was putting it into cad and I just shook my head. It's a Rube Goldberg to slow everything down..... It's crap......
 
The reason they didn't want to publish it to the guys is NOT because it was proprietary..... It was so they weren't embarrassed when anybody saw it.
 
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Why are the 700 ohm resistors getting so hot Perry? Are they small board mounted resistors?
 
On my beast, I remoted (meaning connected via wires) a chassis mounted metal clad 50W Alco type resistor...
 
On my beast, I remoted (meaning connected via wires) a chassis mounted metal clad 50W Alco type resistor...


The trick is to mount new ones to the back of the board and raised up a bit but in this case, it was too late to save the boards.

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That is just silly design Perry. The value of that series resistor ends up being 1.8 ohms which is a ridiculous value for a soft start resistor.
 
the 700 ohm ones run at like 400 degrees. along with the 7.5's and the relay diodes is just too much heat for the board.
 
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