[Horicios]

Hi...my first post here.

This week I built my first kit, an EPQ501...it's been a lot of fun and very rewarding. 
 I just have one final problem with the top pots..."att and kHz" 
 When I set it to the right at 20kHz and slightly adjust the "att" pot, the EQ goes into bypass...it's a mechanical issue. 
 I've resoldered the stepped pots, but it's still the same. It seems like a short circuit inside the pot itself.
..I don't know.

[JPK]

Check that you haven't overtightened the screw on the red knob. This could cause the potentiometer adjustment to also rotate the rotary switch.

[Horicios]

Thanks, I understand, but that's not the problem. It's hard to explain...
When I move the AT pot, the kHz switch doesn't move from its position (20 kHz). It simply goes into bypass while at 20 kHz. It also does this at 15 kHz, but less frequently.
  It seems that when I move the AT pot, something shorts out or loses contact, on the switch causing it to go into bypass.
I could send you a short video

[JPK]

Does the problem persist when the front panel is removed? If not, it would mean that the rotary switch is not perfectly flat on the circuit board, which could be the cause of the problem.
Otherwise, maybe a damaged rotary switch? Contact us for a replacement.