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Hoffman Amps Forum image Author Topic: Pin 3 measurement  (Read 1750 times)

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Offline pbman1953

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Pin 3 measurement
« on: March 15, 2019, 09:43:53 am »
I just learned that my Bias Rite needs a tweak. The meters' power voltage reading is off compared to a stand alone meter.   The Weber company told me about the  trim pot inside the BR to help me match to the stand alone. What started this is that , on my Traynor, pin 3 was 55 volts higher using a stand alone multi meter. It measured around 609 volts vs. the BR was at 552-554.


Due to this I have to take another look at my Sunn 300.


Here's a couple  questions-


Can I pull one tube on the Sunn to read pin 3?


If yes, should I check each socket, pin 3, to see they are the same.


Thanks

Offline sluckey

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Re: Pin 3 measurement
« Reply #1 on: March 15, 2019, 09:51:45 am »
You need the tubes plugged in to get a meaningful voltage reading.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline pbman1953

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Re: Pin 3 measurement
« Reply #2 on: March 15, 2019, 09:59:21 am »
ok, good info.


I suppose I can test while plugged in.

 


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