SOLVED Pharmacist help please!

innerlight

Active member
Hi all!
I have just finished building the Pharmacist. This is my first time sourcing my own parts and drilling the enclosure.
I took my time and kept the soldering pretty neat i think? Be gentle!

The pedal works (and sounds great) on the regular side, however the LED has a slight flicker to it when engaged, like there could be a bridge somewhere I cant see. The BOOST side however does not work at all. When engaged, the LED comes on but there is no signal at all. I have tried to adjust the trimmer and knobs with no change.
I have re-flowed all solder points, and looked around for a bridge somewhere to no avail.
If someone could take a look or offer any advice, id be beyond appreciative!
I am a novice but I have a DMM, so I could troubleshoot with directives.
I'm also wondering if I've installed a wrong component some place?
The part that does work sounds FANTASTIC! I really want to get this up and running, so IMG_0013.jpg IMG_0015.jpg PLEASE HELP ME! :oops:
Thanks, Christian
 
Looking at your photos it seems that the third 2N5457 from the right hasn't been soldered on the right hand leg. See how all the others transistors have a healthy blob of solder around the leg? That could be your dry joint.
 
The 2nd Q6S measurement is mV, right?

Those measurements look good, Q6 & Q7 are biasing correctly.

Recheck your wiring and solder joints to the MACH SCHAU (BOOST) stompswitch.
Recheck the solder joints around C18, C19, R32-R37.
Check C18 for cracks or other damage. I do not recommend using disk ceramic caps, they are fragile, noisy & unreliable. Do you have any spare film caps in the range of 1nF?
This did it! Immense thanks @Chuck D. Bones!
 
What exactly did you find?
I just went through and reflowed all the parts you mentioned, starting with the Mac Schau foot switch (my suspicion is that this was the culprit, as one of the solder jobs on a connection looked a little suspicious). Then I reflowed all of the resistors you mentioned with a little more solder.
Thats all it needed!
Without your guidance I really would've been in the dark.
 
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The 2nd Q6S measurement is mV, right?

Those measurements look good, Q6 & Q7 are biasing correctly.

Recheck your wiring and solder joints to the MACH SCHAU (BOOST) stompswitch.
Recheck the solder joints around C18, C19, R32-R37.
Check C18 for cracks or other damage. I do not recommend using disk ceramic caps, they are fragile, noisy & unreliable. Do you have any spare film caps in the range of 1nF?
@Chuck D. Bones Just wondering for another build (neurocyton preamp), what do you recommend using in place of a 220p ceramic disc cap?
 
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