[doktar]

After completing my build, I tested voltages, they are all within spec.
 
When I try to calibrate,  Step 5- I only get about 15-16V max when it should be 20V

Then in step 6- I get 3 gain reduction LEDS on with all 3 trimmers all the way down (CCW) and cannot adjust to only 1 LED (-3)

Gone through the proceedure twice and same results.

Unit sounds as it should. 

[JPK]

Step 5- I only get about 15-16V max when it should be 20V
How many AC Volts max (against 0V) do you get on TP4 and TP5? (should be 11-12VAC)

Then in step 6- I get 3 gain reduction LEDS on with all 3 trimmers all the way down (CCW) and cannot adjust to only 1 LED (-3)
With PEAK at 0 What DC voltage do you get on TP8? (should be 0V).

[doktar]

After repeating, Im now getting about 23V max in step 5. So good there

Step 6 - with peak at 0 - there is 0v AC/DC on TP5.
  With peak adjusted to 10.6V - i get only -3 LED illuminated, but can adjust because all trimmers are down.
  With peak at 1.5, All LEDS are illuminated.  Still no adjustment.
   I'm closer now, but seems like slightly higher GR meter readings.  The -20 illuminates around 2.2 V

[JPK]

What DC voltage do you get on TP8 (against0V) 
- for Vout = 15VAC (no gain reduction),
- for Vout = 10.6V (-3dB),
- for Vout = 1.5V (-20dB).

What DC voltage do you get on U4 pin13 (against0V) when you turn Trimmer TR1 from 0 to the max. Should go from 0.08V to 0V approx.

What DC voltage do you get on U3 pin2 (against0V) when you turn Trimmer TR2 from 0 to the max. Should go from 0.75V to 0.2V approx.

[doktar]

If I'm understanding correctly, for the first set of measurements I'm adjusting the gain reduction then adjusting the output gain to the voltage you specified (1K tone).

15V no GR - 0VDC
10.6V -3db (one LED) .03VDC
1.5V -20db (all LEDs) .39VDC

U4 and U3 voltages are almost exactly as you specified.
U4 .08V max - 0V min
U3 .719V min .198V max

[JPK]

The first set of measurements is like step 6 in the setup Guide: Start with a 15VAC output voltage then adjust PEAK to get the 10.6V and 1.5V output and measure the DC Volts on TP8.
If this is what you did, then your values are good.

Please describe again the issue, I am lost!

[doktar]

Here are the correct voltages on TP8

- for Vout = 15VAC (no gain reduction),= 0 VDC
- for Vout = 10.6V (-3dB), .050 VDC 
- for Vout = 1.5V (-20dB).  .592 VDC


the -3 LED illumanites at 12.8 V, and both trimmers are all the way down, so can't adjust to 10.6V.


However, now I only can get 2 LEDs to illuminate, no matter where the trimmers are at.