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GB#2: Folsom EC7293: PVI Powered Frontend Amplifier, 60/120w 8/4ohm, 0.0005% THD

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I think the amp sounds excellent.

In retrospect, I wish I built it as a dual mono. I am using a pair of Maggie 1.7i and a Schiit Freya. Sounds marvelous but is probably not a perfect match with the Maggies.. I think it might make it happen as a dual mono.

Just sayin.....only $100 more bucks.....
 
The amp and speakers sound great at low to moderate levels. I feel like they may run out of steam at higher levels. Not absolutely sure that is accurate. there is surely a subjective factor there. I wish I had bought a larger case. Another PSU and TF are not a big expense. Was thinking 120,000 uf vs 60,000 uf of PS capacitance might provide a bit more umph. Not really interested in getting new case and refitting everything to the case.

BTW, my amp went down last weekend. Both amp boards stopped and the the fuse popped when I powered up. I plugged it into the variac and it hummed like crazy at low voltage. There was continuity from hot to neutral at the AC plug. removed the PS and the t/f measured fine. Added the PS and all went bonkers. Nothing looked burned, etc. I had put a lower wattage (1/2 watt resistor at the 10 ohm spot, R2 and R3 from memory). The sizing suggests something more substantive. I replaced with a 3 watt. They measured fine s/p removing them. I replaced the 4 rectifiers (?) and the 1 uf cap. The big caps seemed to measure OK. Put back together and it worked fine. Not sure of the culprit. Guessing the rectifiers but i don't know. So happy I was able to fix it!

Nevermind- powered it up tonight and w/o success. karma for bragging....
 
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I'm pretty baffled at that. Email me pictures please.

Check chip tab isolation to the -v rail (doesn't need to be on).

How much continuity between hot and neutral? The only thing connected to those are the transformer, switch, and fuse.

Are you saying you have a 10ohm resistors somewhere on the PSU???
 
the fuse is a 3a slow blow.

I disconnected the amp boards and put in another fuse. powered on the variac and got 72v both sides once up to full voltage. No continuity from the chips to ground. As for continuity from neutral to hot, it starts at 35 or so and drops to 1.1 (ohms?) in 30 seconds or so. This is connected to the PS but amp boards not connected.

Took out the PS and took pictures. I am inclined to put in a higher amperage fuse I have a 5a fast blow). Scares me a bit.

-the amp worked fine and then went out on power up
-PS measures good now
-the t/f measures fine without the PS
Can't find any bare hot/neutral wires, etc. that appear to be going to ground.



Thanks for your assistance!!!!
Jeff
 

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