Pharmacist

[ALK2MT]

Good evening! I was successful in completing one Pharmacist build but the second one is not going to plan.

I am running a check on resistor values and finding quite a few (10) are bad.

My questions:
1. Grounding, is there any reason to have an insulator between metal case and pots? Case and input threads?
2. Has anyone else had a batch of bad resistors? (Tayda)

Thank you! Appreciate and am grateful for the knowledge base here.

A.

 

[music6000]

You can't measure most resistors once they are installed, you get a false reading!
Check with the Resistor Calculator.
Click on Bands for 5 coloured rings.
10K = Brown, Black, Black, Red, Brown
100K = Brown, Black, Black, Orange, Brown
When there is an issue, it's usually the Multiplier, the 4th Colour Highlited :

Resistor Calculator

Resistor Calculator is an App developed by CherryJourney to help the user find the value of a resistor.

resistor.cherryjourney.pt

 

[JamieJ]

Why have you insulated the pedal internally? Ground is made through the jacks to the enclosure. If you haven’t got a connection to the enclosure that is a problem. Also are you measuring when they are soldered in place? If so values often test differently with a meter.

 

[Guardians of the analog]

you made a lot of choices here that are making things harder for yourself. Any reason why you mounted the pots the way you did? That type of bending seems like it could lead to shorting and or damage to the pot itself. Hope you get this one resolved. both responses above are good places to start. may have to see the back of the board.

 

[music6000]

JamieJ is correct.
If you insulated the Input & Output Jacks from the enclosure, you will get excess noise as the enclosure acts as a shield.
Your Pedal should still work as you have it Grounded from the jacks to the main PCB.
I believe you may have Cold Solder joints from the exploded view of the pedal shows little to no solder on the pads around some of the Pots,
It really needs to come out & remove that red material & show us the Solder side of the circuit so we can see before making anymore responses.
Guardians is correct, doing that to the pots may have cracked the Brown wafer board which will make that pot redundant causing the pedal to fail!

 

[KR Sound]

Guardians is correct, doing that to the pots may have cracked the Brown wafer board which will make that pot redundant causing the pedal to fail!

Any reason why you mounted the pots the way you did? That type of bending seems like it could lead to shorting and or damage to the pot itself

Doing it that way also puts the back side of your board dangerously close to the enclosure, probably why you felt that you had to insulate it.

Mount the pots on the backside (look around here for tons of examples) and the board will not be in contact with the enclosure.

 

[music6000]

Good evening! I was successful in completing one Pharmacist build but the second one is not going to plan.

Did you build the first one like this, you are a lucky man if you did! & it worked!

 

[ALK2MT]

Why have you insulated the pedal internally? Ground is made through the jacks to the enclosure. If you haven’t got a connection to the enclosure that is a problem. Also are you measuring when they are soldered in place? If so values often test differently with a meter.

I will pull the red insulator out and see if that helps.

 

[ALK2MT]

Doing it that way also puts the back side of your board dangerously close to the enclosure, probably why you felt that you had to insulate it.

Mount the pots on the backside (look around here for tons of examples) and the board will not be in contact with the enclosure.

Doing this!

 

[ALK2MT]

Ok. Updates. I removed the red insulating material and looked through all of the solder points for any joints that may be cold.

The good, I am getting closer.
The pedal now will pass a sound on bypass.
When I turn on Footswitch 1, there is no sound, LED is bright, and none of the pots seem to finction.

When I turn on Footswitch 1 and the Mach Shau Footswitch 2, Gain, Mids, and MS Volume all work. Both LEDs are bright. There is a great fuzz sound. Volume 1 still does not work.

Is it possible that the pot for volume 1 needs to be replaced? Any other thoughts on where I should focus in the circuit?

Thank you.

 

[Nic]

As already said, the way those pots are mounted is not ideal... was it to lower your board for the 2 huge caps ?

 

[ALK2MT]

As already said, the way those pots are mounted is not ideal... was it to lower your board for the 2 huge caps ?

Originally yes. I was very careful to bend the tabs.

 

[jwin615]

Check the main footswitch, 1 as you stated. Make sure it is toggling. Can use continuity or resistance test on your DMM. Do this with power not applied. May be worth reflowing those joints as well.
Long header pins work well on this board for straight vertical connection.

Also, pot on left may have a leg u soldered, from the looks of the photo.

 

[Nic]

Also, pot on left may have a leg u soldered, from the looks of the photo.

I would say at least a couple of those pots looks like they could use a reflow.

 

[chris.knudson]

Looks like the issue is that you soldered the pots to the wrong side of the board and then had to bend the legs to get the pots through the enclosure. As some have stated, this could be causing a problem -- those legs aren't meant to be bent that way. Since you bent the legs that way, the back side of your board is likely touching the enclosure (unless you have insulated it), which would definitely cause the pedal to short to ground. Have you tested the pedal outside of the enclosure? Nine times out of ten, if it works outside the enclosure and doesn't once you put it in, something is shorting to ground. Also, I can't tell from the angle of the photo, but it looks like you have black wires connecting to the tip of your input and output jacks (i.e. the + side) and blue wires connecting to ground, but on your power jack you have the black wire connected to the (-) side. You might just want to check the polarity of those connections.