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Harbinger two squealing

Started by redmojosteve, January 06, 2021, 12:30:43 PM

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redmojosteve

Morning
I have seen something like this for the Harbinger one but I never found an answer. I am sure someone has a better idea than me about where I should be concentrating my efforts!
My Harbinger two build does produce the correct output sounds, as far as I can tell, but there is a squeal which follows the volume and modulation of the sound, even without a signal input. To give some idea of the nature of the sound it seems to be like a sawtooth wave at around 2kHz.  Most of the voltages around the board are generally about 5-10% below those in the table in the build doc, but some of the voltages are quite a bit out e.g. IC1 pin1 +4.4V, pin 6 +4.7V, pin 7+3.5V; Q12 B +4.9, E +4; Q14 S +0.45 and the others voltages are more or less as specified, if a bit lower as mentioned above. I use a bench power supply and I have swapped the IC with another new one but no difference. I built the harbinger one some time ago without any problems (and loads of other pedals too, which have all worked!).
I wonder if anyone could give me an idea of what it could be please?
Thanks

joesatch

#1
just finished a harbinger 1.5 and mine is squealing too. i'm using the charge pump option. the vibe and everything works but there is a high pitched squeal. any ideas?

Solved:  swapped out the charge pump IC. i really need to learn to socket all IC's