That did it!!! Thanks so much for the visual aid, it helped this rookie. I appreciate the help immensely. I will put the case back together and see how it sounds.
Thanks again and I will let you know the progress.
Got it up and running. Using an old 70's Luxman receiver's pre-outs and it is silent with no weird audio irregularities. More importantly, it sounds great. There's more detail than I was expecting and the tone is great. Going to play with some tomorrow.
Thanks again, everyone!
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LOL! I was thinking the same thing, not the most subtle of tools for such a delicate Amp!
One channel dead
Thanks Franz. I have attached a couple of photos of the amplifier. I haven't spotted any wiring mistakes. I have made the following voltage measurements; Good Channel - MOSFET Drain 14v, V+ 33.9v, +0 0.035v, VFET case 33.96v, Z1 A 7.7v, Z1 C 14.0v, Z2 A 1.3v, Z2 C 6.00v. Bad Channel - MOSFET Drain 14v, V+ 35.88v, +0 0.024v, VFET case 35.88v, Z1 A 2.85v, Z1 C 13.44v, Z2 A 0.06v, Z2 C 2.89v.
I have tried a transistor tester on both mosfets and vfets (peak design) but don't get reliable readings.
Any thoughts re MOSFET or VFET would be greatly appreciated.
Neil Meredith
Thanks Franz. I have attached a couple of photos of the amplifier. I haven't spotted any wiring mistakes. I have made the following voltage measurements; Good Channel - MOSFET Drain 14v, V+ 33.9v, +0 0.035v, VFET case 33.96v, Z1 A 7.7v, Z1 C 14.0v, Z2 A 1.3v, Z2 C 6.00v. Bad Channel - MOSFET Drain 14v, V+ 35.88v, +0 0.024v, VFET case 35.88v, Z1 A 2.85v, Z1 C 13.44v, Z2 A 0.06v, Z2 C 2.89v.
I have tried a transistor tester on both mosfets and vfets (peak design) but don't get reliable readings.
Any thoughts re MOSFET or VFET would be greatly appreciated.
Neil Meredith
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worth a try - replace 4N35, check resistors connected to it
if that isn't helping, remove mosfet and check it with simple matching jig
all in hope that VFet is ok, and fact that you can vary output node voltage is implying that, same as that biasing parts are OK
just to amuse us, post proper macro pic of Dodo channel pcb
if that isn't helping, remove mosfet and check it with simple matching jig
all in hope that VFet is ok, and fact that you can vary output node voltage is implying that, same as that biasing parts are OK
just to amuse us, post proper macro pic of Dodo channel pcb
Number 82 is Running
Thank you Mr. Pass and everyone else involved in this amazing opportunity.
What a wonderful sounding amp! All of my Pass amps sound great,
love them all but this one is very special as in literally gives me goosebumps special.
Aside from that, I am speechless.
Thank you all again.
-Bill
Thank you Mr. Pass and everyone else involved in this amazing opportunity.
What a wonderful sounding amp! All of my Pass amps sound great,
love them all but this one is very special as in literally gives me goosebumps special.
Aside from that, I am speechless.
Thank you all again.
-Bill
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it is so rude, having both Ducati and VFet amp
Well then this isn't going to help my cause.
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it is so rude, having both Ducati and VFet amp
@bbm3no 992 no party I ZM suggestion for alternative psu filter resistor ?
smell too much for my taste in bedroom...
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