Problem With My Seduction Amp

[M42]

Hi All,

Buoyed by my successful Crack amp build, I forged ahead with my Seduction kit. Unfortunately the amp is not running correctly. I am a neophyte in the diy hobby (the only thing I know for certain is which end of the soldering iron gets hot) and have turned the amp over to a friend who is looking at it for me.

When we powered the amp up for the first time the tube heaters did not activate and none of the LED's were lit. The power transformer seemed to be running considerably warmer than that of my Crack amp...if that's any indication of anything. Nothing smoked...now blown fuse! If memory serves, this was some five weeks ago now, we were getting a low voltage reading for the tube heaters. Mark has since tried powering the amp up with only one tube installed. The heaters for both tubes will come and  the LED's will light (faintly), provided only one tube at a time is installed. Both tubes of course have been swapped in each socket.

Is it possible the transformer is bad? It seems unlikely even to me, but I'll pose the question. I wish I could be more coherent in my description, but it's the best I can offer for now. Any advice/suggestions would be appreciated.

Kind regards,

Jeff

I have reviewed the troubleshooting tips here on the forum...I revisited every step of the build, I'm convinced it's assembled correctly. I have checked every solder joint, but not re-wetted them.

[Paul Birkeland]

Hello Jeff,

I'd run the amp with no tubes installed, the let us know how much heater voltage is available, as well as what the high voltage terminals look like.

If the power transformer is running hot, the likely suspects are a reversed diode or reversed capacitor.  Based on your description, I would suspect one of the 1N5818 diodes or the 10,000uF capacitor.

You can always post a pic for us to look over.

-PB

[M42]

Hi Paul,

Thank you for your assistance....I'll get the details posted as soon as I can.

Jeff

[Grainger49]

If the tubes don't heat nothing will work. 

How did the resistance measurements go?

[M42]

Hi Grainger,

It's been over a month since I've had the amp in my hands, but if memory serves the resistance checks didn't look right either. Disappointing, as the Crack build was problem free. I'll post the details as soon as I have the amp back.

Jeff

[Grainger49]

Ok, the first step is to post the resistance readings that are greater than +/- 15% out of spec.