Chasing hum in one channel.

[Noskipallwd]

My Eros developed a hum in the left channel, it is very low, lower than LP surface noise. This would not bother me normally but it is inonly one channel. It is not tube related, put all of the stock EH tubes in no difference. I re-wet all my joints, did the chopstick test, I even took the choke out of the circuit to no avail. It is also not related to placement, or cables. I am at a loss, God I hate chasing hum!

Cheers,
Shawn

[Grainger49]

It looks like you have tried almost everything.  Since you say cables, did you swap the cables coming into the Eros to see if it is related to the TT setup?

[grufti]

I would poke around in the area of the central audio ground connections one more time. You might want to put even more heat into those ground wire clusters than you have up until now. There isn't much there that's heat sensitive and it takes a bit of doing to avoid incomplete connections there.

[Noskipallwd]

It looks like you have tried almost everything.  Since you say cables, did you swap the cables coming into the Eros to see if it is related to the TT setup?

Yep, the Concepts cables are hardwired so I hooked up the Project. I have 3 different sets of cables for it, tried them all, Nada. Maybe next I will pull the custom caps from the left channel one at a time. Although the voltages are still well within specs one could have small problem allowing it to pick up interference.

I would poke around in the area of the central audio ground connections one more time. You might want to put even more heat into those ground wire clusters than you have up until now. There isn't much there that's heat sensitive and it takes a bit of doing to avoid incomplete connections there.

Thats a good idea Grufti, those connections are really busy, one or more connected wire could have a poor joint, I'll try that as well. It still sounds great and you can't hear the hum when playing a LP, but it was quiet before. I had to turn my amp up to 3 oclock before hearing any noise and that was just a little white noise. It really is a wonderful sounding phonostage, it is not often my expectations for something are exceeded, but the quality of the Eros' sound was definitely better than expected. Thanks for the help guys!

Cheers,
Shawn

[Noskipallwd]

Thanks for the help guys, found the hum. One of the 220 ohm resistors, I think they are the grid stoppers, had a nearly broken lead. Must have over stressed it during assembly, it was barely making connection. Had the same type and value, but different brand in my stash. Replaced it, put humpty dumpty back together again. Is quiet again!

Cheers,
Shawn

[Grainger49]

Shawn,

Those 220 ohm resistors are awfully fragile.  I broke four in a row once.