Attn Carl - HH Build Problem

[adrianwt]

Carl,

I have been ultra careful in using exact parts and all tested perfect until
testing the first amp stage. Like someone else on the list I got an overdriven NE5534P giving 3-4v on pin 6 with 0.6v on pin2! Just in case...I changed both diodes AND changed q1 & q2! However - no change! When Q3 is removed
all the voltages etc are perfect. +5v &-5V supplies to 5534 are spot on!
The only diff is I'm using a TLC555 linCmos timer, but it's pin compatible with 555? The output from the timer measures between 1-2Khz (on freq range of dmm) - although this isn't present on q1 or q2 It seems that q3 isn't turning on/off any ideas whats going on!? I will have to send for new pcb with much more re-soldering!

Yours Screaming, tearing hair out with sparks flying from ears....reaching for the BIG hammer!.
Regards
Adrian

[Carl-NC]

OK... gently put down the hammer and back away from the circuit!

Yes, the TLC555 should work. If your DMM is reading a freq. then it sounds like it's OK. So Q1 might be the problem... double/triple check that it is the right "type" (3906, not 3904) and installed the right way. Also that the value of R5, R6, and R15 are correct. And, that you have shorted R7 and R8.

- Carl