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Build help and troubleshooting => MP573 Microphone preamplifier => Topic started by: toakley on March 25, 2021, 06:27:16 AM

Title: MP573 Failing First Setup Test
Post by: toakley on March 25, 2021, 06:27:16 AM

Hello all,

Just finished the MP573 preamp, but I am failing the first setup test. When I put my DMM probes between V- and OV, or OV and V+ I am getting no resistance reading at all. I have my DMM set to 2000, and then I go up to 20k, but still no reading.

No metal parts are touching the chassis, phantom is off, the polarity is set to POL, input impedance is set to 300, both jumpers are on, I see no solder bridges, output transformer is disconnected while testing. Not sure if the position of the gain switch or the output pot matter during testing, but they are both halfway up.

Any help would be appreciated.
Thanks.

Title: Re: MP573 Failing First Setup Test
Post by: JPK on March 25, 2021, 08:30:42 AM

Quote

I am getting no resistance reading at all

This is excellent: infinite resistance means no short circuits.

Title: Re: MP573 Failing First Setup Test
Post by: toakley on March 25, 2021, 04:25:03 PM

Quote from: JPK on March 25, 2021, 08:30:42 AM

Quote

I am getting no resistance reading at all

This is excellent: infinite resistance means no short circuits.

Oh great haha. I was a little confused because the directions say I should be getting a reading greater than one kilo-ohm. What does that mean then?