Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Stereomour => Topic started by: Bartguy on March 03, 2014, 03:51:28 AM

Title: Buzz in right channel [solved]
Post by: Bartguy on March 03, 2014, 03:51:28 AM

My build is complete, I figured out the transposed T5 & T6 issue in the manual and my Stereomour is playing through my Orca speakers. The only issue is a right channel buzz that doesn't get louder when the volume is raised, but is noticeable at regular listening levels and distance.

Any advice as to where to start looking for the cause?

Thanks.

(I'll post pics soon.)

--MB

Title: Re: Buzz in right channel
Post by: Paul Birkeland on March 03, 2014, 06:18:09 AM

The first thing to try would be swapping tubes.

The next thing to triple check would be the ground jumper between T8 and T10.

-PB

Title: Re: Buzz in right channel
Post by: Bartguy on March 03, 2014, 01:54:00 PM

Thanks, I'll try that and report back.

Title: Re: Buzz in right channel
Post by: Bartguy on March 10, 2014, 05:37:22 PM

Well, I swapped the power tubes and the buzz didn't move channels, so I guess its not them. Could it be the 12AT7 tube?

I also checked terminals 8 & 10. I have continuity between the volume attenuator & T8 &T10. I also reheated all the solder joints at T8 and T10 as well as anywhere else that connected to ground, so I don't think it's a cold solder joint.

Again, the buzz doesn't change with the volume. It's steady no matter how loud I turn it up.

I posted some pictures of my build in case that helps. Any other likely culprits to look for?

Title: Re: Buzz in right channel
Post by: Paul Birkeland on March 10, 2014, 05:51:20 PM

You have an empty "K" solder pad on the power supply board?

Title: Re: Buzz in right channel
Post by: Bartguy on March 13, 2014, 09:07:00 AM

Doh! You were right. I missed that solder. Funny, it didn't affect my resistances or voltages. But after soldering, the buzz in one channel is gone.

I have a much lower level of hum in both channels, but maybe that's normal. I did adjust the hum pots as best I understood it.

Thanks again for the eagle eyes.