The Tone God's Punisher - debugging help

[PandaFeet]

1.What does it do, not do, and sound like?

The Punisher is described as a dynamic power supply sag simulator. This is "not an audio effect but a companion effect that is to be used to control another effect to provide new sounds." Essentially the circuit is an envelope follower that turns a JFET into a voltage-controlled resistor. This voltage-controlled resistor is in series with an effect's power supply. The guitar/audio signal trigger the envelope, which alters the voltage of the power going into the effect. The Punisher has been likened to "a dying amplifier with sagging tubes" or a "frying, orange tube." The circuit is based off the Dr. Quack Envelope Filter (https://www.muzique.com/schem/quack.gif).

This circuit is more popularly known as the basis for the Crackle/Boom feature of the SSBS F__k Overdrive. However, I do think the F Overdrive does take some liberties. For exampe, from seeing the PCB on Instagram, there is a C5K pot to control threshold. I think that particular pot is associated with the emitter of 2N5089, but I cannot confirm. I do know the parts count of the Crackle/Boom matches that of the Punisher except for that aforementioned C5K pot, the omission of the Punisher's sensitivity control, and what appears to be a singular 15K resistor.

I am having a few issues:

• I have managed to get the circuit to work in some capacity. I tap my finger on the input, the envelope "activates," and the power out reduces to 1-2 volts, then the returns back to normal (9.23 V). Here is a video demonstrating: https://www.youtube.com/watch?v=xe4qj9YMndg. This is how the circuit is supposed to work overall.
• When I try to feed in an actual guitar signal, the envelope does not activate. It's only when I tap my finger on the wire attached to input that the envelope triggers.
• When I try to feed in an actual guitar signal, the envelope does not activate. It's only when I tap my finger on the wire attached to input that the envelope triggers.
• After 3-4 taps, the circuit gets "locked up," meaning, the power-out will return to 9.23 V, but then envelope will never activate again. I have to power down the circuit, wait a few seconds, and then reactivate. However, upon reactivation, the sensitivity (B100K) and trimpot on Range, have to be readjusted. There is another debugging post by another user that identifies this same issue - but no resolution to the problem.

2.Name of the circuit.

Punisher.

3.Source of the circuit (URL of schematic or project).

https://www.thetonegod.com/diy/punisher. The creator of the circuit is a mod on this site. I did amend his schematic, however, to indicate the part numbering (LEDA, LEDB) and identify the correct (?) pinouts of the IC.



Here are pictures of my breadboard:









Note: Please disregard the extra LED and resistor on the left breadboard; those are just indicator lights to let me know the board is getting power. Furthermore, I did test the circuit without these extras in order to ensure they were not affecting the integrity of the circuit. White jumper is the "input cable/wire."

4. Any modifications to the circuit?

No.

5.Any parts substitutions? If yes, list them.

As I present it in this post, no substitutions. Although I did experiment with with a different ICs (4558, 1458) based on info about "swing voltage" I read in regards to the Dr. Quack. I also tried a 22uF electrolytic capacitor (vs. the 10uF) because I read about using that value in the Nurse Quacky, a derivative of the Dr. Quack. This did not fix my issues.

6.Positive ground to negative ground conversion?

No.

7.Turn your meter on, set it to the 10V or 20V scale. Remove the battery from the battery clip. Probe the battery terminals with the meter leads before putting it in the clip. What is the out of circuit battery voltage?

9.27 V

Now insert the battery into the clip. If your effect is wired so that a plug must be in the input or output jack to turn the battery power on, insert one end of a cord into that jack. Connect the negative/black meter lead to signal ground by clipping the negative/black lead to the outer sleeve of the input or output jack, whichever does not have a plug in it. With the negative lead on signal ground, measure the following:

Voltage at the circuit board end of the red battery lead = 9.23
Voltage at the circuit board end of the black battery lead = 0.4mv

Now, using the original schematic as a reference for which part is which (that is, which transistor is Q1, Q2, etc. and which IC is IC1, IC2, C1, and so on) measure and list the voltage on each pin of every transistor and IC. Just keep the black lead on ground, and touch the pointed end of the red probe to each one in turn. Report the voltages as follows:


Q1 (2N5089)
C= 9.23 V
B= 6.4 mv
E= 0.4 mv

Q2 (2N5457)
D= 9.23 V
S= 9.23 V
G =9.23 V
No continuity noted between parts. JFET was sourced from StompBoxParts. JFET works in my other builds that utilize JFETs. JFET Trimmer (max) set to 0. I assume this trimmer is to set the overall voltage of the effect circuit.

IC1 (TL072)
1= 8.62 V
2= 0.7 V
3= 1.5 V
4= 0.1 mV
5= 1.8 V
6= 1.5 V
7= 1.5 V
8= 9.23 V

LEDA
A = 1.8 V
K = -0.2 mv

LEDB
A = 1.5 V
K = 141 mv

LEDS have been matched. Forward voltage is 1.94 V.

1N4148
A = 135 mV
K = 7 mV

Range Trimmer = approx. 77k ohms, but does need to be readjusted after each use.

Relevant Posts:
https://www.diystompboxes.com/smfforum/index.php?topic=53591.msg407069#msg407069
https://www.diystompboxes.com/smfforum/index.php?topic=53614.msg407482;topicseen#msg407482
https://www.thetonegod.com/diy/punisher

[PandaFeet]

Solved!

I asked the minds of Reddit about the issue, and there were two pivotal things missing from the original schematic: Biasing the op amp! Two resistors are needed to get the thing working. I have included an updated schematic below:




Additional changes I will test out:

• Increase gain of stage 2by going with a value higher than 2m2. This will help produce a greater signal from the envelope follower to the LED.
• Now that the biasing issue is resolved, I would recommend increasing the 10uF electrolytic capacitor to 22uF or even 47uF.
• 100n-220n capacitor coming off of pin 1 to the Sensitivity potentiometer.
• Instead of just connecting pin 1 and 2, add an additional gain stage to strengthen the signal: Place a 100k resistor there plug a 10uF cap to resistance then to ground - like the MXR Micro Amp.

[antonis]

-I'd suggest to lower 10k resistor value (the one wired on pin 6) instead of raising 2M2 one..
-I'd also suggest a slightly different bias configuration, like: lower 1M resistors values down to 10k-47k, place a 1M resistor between   
their joint and pin3 and a 47μF to 10μF between those 3 resistors joint and GND..
-Capacitor between pin 1 & Sensitivity pot lug 3 is only needed in case of pot crackling issues experienced..
-For a buffer with gain, you need 2 resistors (one across pins 1 & 2 and another one between pin 2 and GND)..
You'll also need 2 caps, one in series with the gain resistor (like the 10nF in series with 10k) and another one in parallel with the 
feedback resistor (between pins 1 & 2)..
(it should also be a good idea to place a shunt cap across 2M2 resistor..)

[duck_arse]

and as Adonis always says, welcome to the forum.

where is that first incorrect circuit diagram hosted/published/located, pray tell.

[PandaFeet]

where is that first incorrect circuit diagram hosted/published/located, pray tell.

https://www.thetonegod.com/diy/punisher

That is from the circuit creator’s website. He is also a mod here.

[PandaFeet]

-I'd suggest to lower 10k resistor value (the one wired on pin 6) instead of raising 2M2 one..
-I'd also suggest a slightly different bias configuration, like: lower 1M resistors values down to 10k-47k, place a 1M resistor between   
their joint and pin3 and a 47μF to 10μF between those 3 resistors joint and GND..
-Capacitor between pin 1 & Sensitivity pot lug 3 is only needed in case of pot crackling issues experienced..
-For a buffer with gain, you need 2 resistors (one across pins 1 & 2 and another one between pin 2 and GND)..
You'll also need 2 caps, one in series with the gain resistor (like the 10nF in series with 10k) and another one in parallel with the 
feedback resistor (between pins 1 & 2)..
(it should also be a good idea to place a shunt cap across 2M2 resistor..)

Thank you, I will experiment with the changes you have suggested.

Also, do you have any idea what the trimpots do?

I'm assuming Range is how far down the voltage will drop, and Max is to adjust the power that the effect pedal will require in general.