Reduction Hum and No Playback [resolved]

[OverAnalyst]

ahhhh, yes. After removing the tubes, I get * or 4Mohm range which match the spec.  Good to go there. So I'll go ahead and perform voltage checks, unless there's anything else I should do?

[Paul Birkeland]

I think you can move on to voltage checks.

[OverAnalyst]

so finally got back to the voltage checks. And I'm also working to the 10.3.19 manual. I have two terminals out of spec (same as first time around)

44 - 78V (should be 0V)
45 - 77V (should be 0V)

I have a couple pics if that helps....

[Paul Birkeland]

Those are just errors in a manual that our automated download system doesn't want to let go of.  If you have good voltages up front, everything in the back is going to be working OK.

[OverAnalyst]

Still get the hum on both speakers and no playback. I can slightly hear a little noise coming from the record, but it is pretty much nothing.

Back to your reply #12, I did check the RCA inlet plugs. I think I see a problem. The stack in the instructions (page 13) shows the chassis, red flat washer, washer tab, and then the two nuts. On my build, I have chassis, washer tab, red washer, and the two nuts. Looks like my red washer and washer tab are flipped on both RCA plugs. Could this be the culprit???

[Paul Birkeland]

What AC voltage ranges does your meter have?

[OverAnalyst]

600V

[Paul Birkeland]

That's as low as it will go?

[OverAnalyst]

ahhh, it does measure mV, but will need to dig that up. Fluke 107

[Paul Birkeland]

You need to set the meter to MV with the ~, then use an 1/8 to RCA cable to connect your phone to the Reduction.  On your phone, download one of the many free signal generator apps and use it to make a sine wave at 60Hz.  With the volume all the way up, you should see 300mV to 500mV at the ends of the RCA plugs with the 1/8" end plugged into your phone. 

Let me know when you're there and we can proceed with tracing some signal in your amp.

[OverAnalyst]

confirmed. I get get 400mV

[Paul Birkeland]

Groovy!

Plug those RCA cables into the Reduction, leave the Reduction off, then measure the AC voltage across the RCA jacks.

[OverAnalyst]

so I took measurements from the nut and the center of the plug. On the both A and B sides, I read 400mV.

[Paul Birkeland]

OK, now you'll want to turn your phone down till you see about 10mV coming into the RCA jacks, turn the amp on, then read mV between ground and terminal 6 as well as ground and terminal 27. 

[OverAnalyst]

6 - Around 130mV and fluctuating
27 - Around 140mV and fluctuating