Finished Crack build, need help with low voltages [resolved]

[Paul Birkeland]

Just to be thorough, try swapping the 22K resistors. 

Also, with no tubes installed, what DC voltages do you get at:

Terminal 21
Terminal 2

-PB

[timindq]

With no tubes installed I get 236VDC at T21 and 230.6VDC at T2. I'm heating up the soldering iron now and will get back in a minute or two.
Thanks for the assist.

[Paul Birkeland]

Hmm, OK, those voltages indicate 11mA of current draw with no tubes installed. I bet if you remove the 22.1K resistor between 4 and 5, you'll discover that your voltage at T2 will pop up a bit.

I'm still suspecting a short around the socket.  It may be debris in there, look for something touching A1 that shouldn't.

-PB

[timindq]

Swapping the resistors did not help. But I read your last response and went back and checked the tube sockets. I saw no issues but did wiggle them about and blew some air at them.
I then checked voltages and no longer had the drain at T5!!!
I plugged in the 12AU7 and both LEDs lit!!!
I'm going to give the tube sockets a thorough cleaning and try it out.

Another plus: with all this turning on and off and measuring voltage and resistance, I have yet to shock myself!

Thanks for the help and please let me know if there is something I should do before proceeding.

[Paul Birkeland]

Yeah, we may never know what was stuck in there, but I'm glad the drain is gone.  The sockets are two pieces of ceramic that are riveted together, and it's possible that something worked its way in there.

In any event, if all your voltages look good, go ahead and give it a listen!

-PB

[timindq]

IT SOUNDS WONDERFUL!!!
Seriously, no hiss, no hum, k.d. lang never sounded so good. With the music on pause I maxed the volume and still heard nothing but silence.

Thanks again for your help Paul. You can relax for a little while as I'm going to listen like this for a couple weeks before building the Speedball...We'll see how patient I am.