Harbinger one - too much distortion?

[midwayfair]

the voltages on the FET are

0.00
0.26
17.7

.26 for the source?

That's crazy low.

[Cortexturizer]

Hm I cross checked those with brejna on facebook and he has the same voltages basically.

[RobA]

I just finished mine and it's working.

I measured the voltages at the JFET and mine read

9.4mV
326mV
17.49V

I did use a different JFET, the FJN598J.

[madbean]

the voltages on the FET are

0.00
0.26
17.7

Hmm. Maybe try bumping R51 from 4k7 to 10k or 22k?

[brejna]

I have same readings with and without FET..

[Cortexturizer]

just got from over to a friend's...plugged the pedal, and no buzz on the modern mode whatsoever. harbinger works in mysterious ways it seems. weird. dead quiet now. I did open it prior to plugging it in - preparing for the troublshooting session. obviously something was touching the chassis that now is not after I've allowed the board to wiggle in there a few mm. closed it, and still working fine. oh well, with tight builds like my multi here, it is to be expected. will not open it soon again for sure. loving loving loving this pedal. definitely a fav modulation effect ever. it can never sound out of place like a phaser can, that's what I like best about it.

[RobA]

Glad you got it working and it's (almost) solved. This is a really nice effect. Now if I can only figure out where to calibrate it to. The problem is, it sounds good everywhere for the gain and offset trimmers and I've got no idea where to set them to be ideal! I need to find a factory calibration manual or something.

[Cortexturizer]

Well pretty much everybody says that you should set the offset so the lamp never goes fully off. I've set my gain knob so that when my Intensity knob is on full I get too much throb - that situation is only good if you have your speed knob almost all the way down. The design makes the lamp shine brighter when increasing the speed, so that's kind of...unfortunate.
I would say work on having your lamp never go off, the best settings are to be found tinkering with the offset trimmer and not the gain trimmer. I have the gain trimmer on 60-70 percent from full and it sounds spot on.

[RobA]

Well pretty much everybody says that you should set the offset so the lamp never goes fully off. I've set my gain knob so that when my Intensity knob is on full I get too much throb - that situation is only good if you have your speed knob almost all the way down. The design makes the lamp shine brighter when increasing the speed, so that's kind of...unfortunate.
I would say work on having your lamp never go off, the best settings are to be found tinkering with the offset trimmer and not the gain trimmer. I have the gain trimmer on 60-70 percent from full and it sounds spot on.

Thanks for the info. I'll give that a shot. I need to get the sound pretty optimal before I start subbing in new caps to see how it changes things.