Slight noise in right channel only [solved]

[Loquah]

Hi all,

Just finished building a Crack for a friend and it has a faint hum in the right channel which is just above what I would consider an acceptable level (esp. because it is clearly not present in the left channel).

I've emailed to check if it could be the known transistor issue from some of the past Speedball kits, but thought I'd also post to see if there's anything else you think I should be checking.

The sound is consistent with / without connections to the RCA inputs and is not affected by the volume control. My friend bought some alternate power and input tubes, but swapping the input tube to a cleartop had no impact and the alternate power tube may not be a 6080 equivalent because it produces electronic noise when used that makes me think it's not actually the replacement option he thought it was.

[fullheadofnothing]

This is a different issue. The humming with the 350s was occurring with the volume pot turned all the way down and affects both channels. Did it hum before installing the Speedball? This sounds tube related, and will quite possibly go away when the tubes have been used for 50 hours or so. Try known good tubes.

[Loquah]

Ok. Thanks Josh.

Unfortunately, I don't have any known good 6080s so will have to wait till my mate's back from holidays to buy some new ones and test.

I went straight to the SB install because it was a custom build on multiple levels so I didn't want to start stock and then have to rebuild.

[Loquah]

I did some further research and the tubes he bought are Russian 6AS7 equivalents. I gave them a few moments more and they settled right down and sound great!

Problem solved as it was a tube issue only. Thanks for your help, Josh.