Crack readings help

[Paul667]

I just finished soldering my crack amp and all the ohms read normally, but the dc readings are all 0, any suggestions?  Also the sound works, but it has a lot of static and pops. I think a tube might be bad?

[Paul Birkeland]

All the DC readings being zero would suggest an issue with the meter being used.  Some meters require you to move the probes to different plugs to measure DC, I would suggest starting there.  I can be 100% sure you have DC voltage, otherwise there would be no pops. 

A few pops here and there during startup wouldn't be that abnormal, especially if you have a fresh EH12AU7 right out of the box, I'd check the voltage ratings out to be sure. 

-PB

[Grainger49]

I have to ask, did you put the fuse in?  Was it in the right position?  There are two positions you can put a fuse in the fuse holder.  The one you want is the farthest from the back part.

If this is your problem, don't feel alone, you are not alone.

[Paul667]

Yeah, I put the fuse holder in backwards, but I put the wires in right. Would that really make a difference? I went through and re-soldered everything and now its clearer, but I still get some static and the right earphone is quiet. Any suggestions?

thanks again

[dwilli852]

For the no sound in the right earphone. Make sure the output caps are installed correctly. That's the 100 uf caps. Also try a diffrent set of headphone if you have them.

 If you resoldered all the connections and it made an improvement you might be on the right track. They need to get hot enough for the solder to flow.

[Paul Birkeland]

I'd start by listing your voltages, especially any that are off-spec.

[Paul667]

Alright I think I've got this thing to work for the most part. When it is turned on it sounds clear for about 15 minutes, but then the static starts to get pretty bad. One of the LEDs (the one on A3) turns on at first, then eventually starts to blink on and off and turns off.Again the readings (AC/DC) are close to normal, my meter is a cheap one. I think the problem could be with the 22.1 K resistor. It's slightly cracked open. Is there a place where I could buy another one?

 

[Paul Birkeland]

Shoot an e-mail to queen(at)bottlehead(dot)com and we can get out another 22k resistor for you.

An intermittent connection at that resistor could make the LED flash (I honestly can't think of another explanation at the moment).

-PB