No sound right channel [solved]

[tvrtony]

I have just completed building my Crack and have no sound in the right channel.  I have checked the wiring and cannot find any problems.  Voltage checks were also OK.  Does anyone have any suggestions about what could be the issue?

[Loquah]

Do you happen to have spare tubes to test to see if it's one of the tubes?

[Paul Birkeland]

Turn the volume control all the way up, then measure the resistance between the center pin and ground lug of the right and left RCA jacks. Is there a pronounced difference?

[tvrtony]

Installed a spare 12AU7 and this made no difference.

Measured resistance on the RCA jacks at max volume control (power not on).  Left channel 100K, right channel 98K.  The centre pin of the right channel does move a small amount if you move it from side to side but the left channel is completely firm.

[Paul Birkeland]

If the ring terminal (middle) of the output jack is shorted to the sleeve (closest to chassis), then you'll get no sound out of the right channel.  This will present itself as a 0 Ohm resistance between either terminal 6 or terminal 10 (I don't remember which off the top of my head) and ground when headphones are plugged in.

If this is not the case, can you download a 60 Hz tone to play through your Crack?  I can help you follow the signal through the amp to see where it's getting hung up.

-PB

[tvrtony]

Thanks PB for all your suggestions.  I went back and checked all my resistances and in the process found a lose ground connection on one of my RCAs.  Problem fixed.  The sound is wonderfull already!

Cheers.