Buzz in right channel [resolved]

[SammyJ]

Hey all, I’ve developed an audible hum in one channel. Pretty sure I have a grounding issue somewhere, but hoping to see if there might be some targeted guidance before I shotgun solder into it.

Details:

• Noise does not follow tubes
• I’ve stuck in metal shorting RCA plugs. Buzz gets MUCH louder when I touch affected channel’s plug. Touching non-affected channel’s plug does not generate noise in that channel.
• Plugged directly into wall. Turned off and unplugged all other electronics in vicinity.

Any thoughts would be much appreciated!

 

[Paul Joppa]

My first guess is indeed a failure of the chassis ground connection to the RCA socket outer shell. I checked the manuals (original 2013 and v.1.1 2019) but couldn't see where that should occur, it's too crowded. Do all eight of the socket-mounted LEDs glow?

That's about the worst place to be working on the solder joints, crowded with capacitors and LEDs. So be careful!!

 

[SammyJ]

Thank you for the reply! I *think* I found the culprit, but the problem seems multi faceted. One, one of the cap wires was touching the outer sleeve of the RCA jack. Moving it slight solved the buzz. Second, the jack itself is loose, I got it tight enough to stick in an actual connection and seems fine for now. I’ll eventually need to tighten it, but given its position, it will likely involve me having to remove a cap to access it. A problem for future me.

Thanks again!