Getting buzz/hum and mono on crack [resolved]

[Caseystonequest]

Hello! I just finished my crack build, all voltages and resistance testing correctly and I’ve tried all the troubleshooting options so far but am still getting music only in left ear and getting a steady buzz/hum in the right ear. This happens without the RCA plugs in and doesn’t change with the volume knob.. buzz is consistent even with volume all the way down.

I’m at a loss currently but I must have missed something or still have some solder issues. I’m attaching some pictures, is anyone able to spot an error or have something else I can check?

Thanks,
Casey

 

[Paul Birkeland]

Definitely attach some pictures and we can have a look.  Also post your voltages on terminals 1-10 just to be sure.

 

[Caseystonequest]

Hey thanks for the quick reply! I was having trouble uploading pics from my phone so i had to convert them on my laptop, if you need closer up or better pics I can get them and the specific voltage readings tomorrow!

 

[Paul Birkeland]

I do not believe you can pass your DC voltage checks with no wire connected to B1.  I would also invest in a proper set of side cutters (CHP-170 are recommended), then trim all those leads that are poking out from everywhere.  There are a bunch of these that are perilously close to causing shorts. As an example, the lead you have coming out of terminal 19 will cause major problems if it touches the chassis plate.

The red wire connected to A6 needs its bare end bent up, not around the side of the tube socket pin.  Putting it around the side puts it too close to the adjacent pin.

 

[Caseystonequest]

Hey thanks so much Paul I’ll get to work and try this stuff out and get new readings to you. There was one terminal reading a bit high but it was within the % range. It’s fully possible there was some other mistakes during the reading but everything else was spot on the correct number except that one.

Also the red rca jack on the bottlehead may have an issue that’s related to the problem, it’s a bit loose and the plug doesn’t dig exactly snug, there’s a little wiggle room. They are brand new rca decently high quality as far as I know and the other three fit snug.

Thanks,,
Casey

 

[Caseystonequest]

Hey Paul, the amp is over at my father in laws but he ran the voyage check again and here are the numbers he got:

1:77.5
2:164.3
3:0.0
4:164.6
5:76.5
6:0.0
7:139.6
8:0.0
9:101.5
10:0.0

#7 is reading higher now than it did when we were testing it the other day

Thanks again for your help

 

[Paul Birkeland]

Did you make the connection to B1 that's missing?  Running the amp without it is really hard on the 6080, so that should be priority #1.

 

[Caseystonequest]

I haven’t been able to get over there yet but I get the new wire cutter and will head over ASAP to try trimming/fixing that stuff! What would I connect B1 to? Is that one of the steps that had multiple
Options based on the initial testing

 

[Paul Birkeland]

This is well covered in the manual.  You can open the PDF and just search for "B1".

 

[Caseystonequest]

Hey Paul, can’t believe we missed a whole step with the B1 thing  : but after doing that and clipping the leads it all appears to be working correctly!! Thanks so much for your help