Step 39 Voltage

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Step 39 Voltage

Postby brettyc » Mon Feb 22, 2010 12:57 pm

My voltage between L3 and L4 is 1.9V. Is there a best first place to look for my screw up? Thanks!
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Postby tpryan » Mon Feb 22, 2010 1:13 pm

Does the voltage change over time, or is it stuck at 1.9V?
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Postby brettyc » Mon Feb 22, 2010 6:57 pm

It does not change over time, but it does change with a change in gain setting. I also have -16.9V at the junction of R8-R9 and I have 1.6V at the junction of R29-R30. Thanks!
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Postby brettyc » Mon Feb 22, 2010 7:38 pm

Okay, at the very least I installed Q2 backwards. I guess this is what I get for attempting to finish it at 2am.
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Postby brettyc » Mon Feb 22, 2010 8:48 pm

Okay, I managed to spin Q2 around and mount it correctly. All voltages are correct now and it sounds good! Switching through the gain stages soon after power up results in large pops but, after waiting a while they are just small clicks. I'm assuming that's normal power up behavior, right? Thanks!!
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Postby tpryan » Tue Feb 23, 2010 10:32 am

Good job, I have to say you lucked out by not blowing up Q2. The clicks are normal and get quieter as the servo nulls out the DC offset at the input.
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