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Tube Amp help?

I'm not member of KWartzlab per-se but believe in the ideology of hacker/maker spaces, and do a lot of DIY (from kits/internet instructions). That being said, I recently assembled a Starving Student Millet Max headphone amplifier kit, and am sad to report that powering on the unit I was given a light show (LEDs lit up) and spark storm (short), nothing seems to be out of place, and in theory nothing has changed, but now the LEDs no longer light up. I've taken it all apart and done what I could to look for damaged parts, or causes of the short, but have been unable to find any. I'd bring it to an open Tuesday to see if anyone could help, but I do not have access to my own transportation and work nights. But if anyone is located or willing to travel to my place to help in diagnosing the issue, or possibly shedding some light, I'd greatly appreciate it.

documentation on the amp:
http://www.pmillett.com/starving.htm
http://www.diyforums.org/SSMH/

I live around the downtown core by Ainsle St.

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  • By Anonymous at 07/23/2010 - 22:17
  • reply

I don’t see LEDs on the

I don't see LEDs on the schematic - where did you put yours?

Where did the sparks/smoke come from?

At first glance I'd check to see if C1, C6, Q1 or Q2 are backwards (and will need to be replaced if they were). Then I'd look at the wiring to the tubes. But really, it's hard to say for sure without seeing it in person.

well mine was built from the PCB model

Mine was built from the PCB version, I'll check the caps and whatever the Qs are... lol

http://beezar.com/oscommerce2/catalog/product_info.php?cPath=38&products...

the sparks shot out of the enclosures rear right segment, so the power switch area... there were loud pops and crackles and a nice shower of sparks... I mean nothing fear-worthy (years worth of melting mother boards and frying high end enthusiast PC gear) but, I never plugged my tubes into it for the test (the tubes I purchased are top end for the amp, $50 for the set and equate fro nearly 1/3 the cost of the kit) but it perturbs me that the LEDs no longer light up... so I've kind of shelfed it so far. But I'll take a look, thanks :D

Hmmm, I wonder if one of the

Hmmm, I wonder if one of the mosfets (Q1, Q2) ended up being grounded through the case.

What is the resistance of the entire circuit as seen by the power supply?

If you plug in just the power supply, do you get a nice 48-51V at the output?