Need help with my new J99s - SOLVED

[quintosardo]

Hi,
I just built two more J99s.
They are a bit different from the one I already had (two years older), but I followed the new instructions carefully.
I didn't install the IC opamps, I bought two pairs of opamps from SCA.

My problem is:

I still didn't put the discrete opamps in place. Just setting the voltages to +/-24V for max headroom. The positive voltage is ok, starts from 14V and, while turning the pot, raises to whatever I want.

The negative voltage doesn't work! It stresses the power supply (the led goes of and sometimes on), the voltage on the wiring harness goes a bit low, the regulator for negative voltage goes very hot and I cannot get more than 1.5V (oscillating) on the opamps.

The strange part is that I've built these new 2 J99s one by one, in different days, and they behave EXACTLY the same.

I've verified the diodes, the ICs, etc, everything looks fine (obviously it isn't, but where?)

I've tried to connect just my new DI to the wiring harness and everything looks fine.

Any idea?

Any error in the docs I should know of?

Thank you

Quinto

[quintosardo]

Ooops,
that's incredible what wrong tantalum capacitors can do.
Everything works fine, now
Thanks