[Slembones]

 this is the hi freq eq tests. the boost is a bell when it should be a shelf. the cut is a shelf. Did I do something wrong?  please advise. the unit works fine but thought I would lab test. the plots for mid and low are as expected

[JPK]

It is a shelf but it is followed by a high frequency attenuation after 20kHz caused by the compensation caps in the circuit.
Can you make another diagram with a +/-6dB correction?

[Slembones]

can I mod the unit to be flat to 50K and restore the shelf

[Slembones]

the unit is beginning rolling off at 10K even with the band switches set to "off"

[Slembones]

 the red Line is switched out and the blue Lin is switch in but with all bands "off"

[Slembones]

This sweep has about 6dB boost and cut you can see the roll off. I also included a flat setting 

[Slembones]

Found the measurements I made of a real 1073. Here’s the flat frequency response at a few different gains
flat to 50k Here’s the 1073 High shelf response 

[JPK]

OK, you may have an issue somewhere.
Please wait until I am back at work (end of July) so I can help you.

[Slembones]

I have traced it to the discrete amps circuit with a scope. my component installation is correct. I think the feed back circuit at the end of the descrete op amp is rolling off the highs too soon? (guess). it is happening in both amps the same. the feedback (470pf on A and 150pf on B) cap on the outside of the circuit has little to no effect.  could I have a bad component? 

[JPK]

Actually, this is the normal frequency response of the original 1073. About -1dB at 20kHz.
I guess that the modern reissues are modified.
You can make the frequency response flat up to 20kHz by changing the value of 2 caps:
C47 at 100pF (instead of 470pF),
C60 at 47pF (instead of 150pF).