Hi everyone, hi first, as this is my first post here!
A few months ago, I built a Muzzle (Classic) pedal from a Musikding kit. I believe the circuit works as intended. I really like it and agree it's one of the best noise gates I've ever used!
What bothers me is whether the pedal behaves correctly when the threshold is set low (below approximately 1/3; high sensitivity setting for range switch). When the input signal is zero (input jack tip connected to the ground), the LED indicator suggests that the pedal is never gating. Given the way the threshold pot works (its setting also affects the dynamics of the noise gate), I cannot say if the gate really works, as the output level difference is subtle. I took a few measurements, and indeed, the red LED indicator starts working when there is at least 0.6V at pin 18 of the IC - this is expected as lower values won't turn on the Q3 transistor. When the threshold knob is set to lower than 1/3, there is less than 0.6V even when the input is grounded, so the LED won't turn at all. The voltage sets at around -100mV when the threshold is further lowered to its minimum.
I don't know whether this works as intended and the LED indicator won't turn on when the threshold is set low by design, or there is something wrong with my circuit. Can somebody please tell me how your build behaves?
I took some other measurements, and the only thing I found strange is output voltage from LT1054 - instead of -8.4V on pin 5 (9V minus voltage drop on D1), I only get around -8V. Because of the voltage drop over Q2, I have around -7.4V as the negative power supply for the circuit. I am unsure if it matters and can affect threshold control.
My build uses THAT4301 retrofit module. Few photos attached:
- red LED indicator on when threshold is set just to the point when voltage equals 0.6V
- red LED indicator off even there is no input signal
- general gut shot of my build
A few months ago, I built a Muzzle (Classic) pedal from a Musikding kit. I believe the circuit works as intended. I really like it and agree it's one of the best noise gates I've ever used!
What bothers me is whether the pedal behaves correctly when the threshold is set low (below approximately 1/3; high sensitivity setting for range switch). When the input signal is zero (input jack tip connected to the ground), the LED indicator suggests that the pedal is never gating. Given the way the threshold pot works (its setting also affects the dynamics of the noise gate), I cannot say if the gate really works, as the output level difference is subtle. I took a few measurements, and indeed, the red LED indicator starts working when there is at least 0.6V at pin 18 of the IC - this is expected as lower values won't turn on the Q3 transistor. When the threshold knob is set to lower than 1/3, there is less than 0.6V even when the input is grounded, so the LED won't turn at all. The voltage sets at around -100mV when the threshold is further lowered to its minimum.
I don't know whether this works as intended and the LED indicator won't turn on when the threshold is set low by design, or there is something wrong with my circuit. Can somebody please tell me how your build behaves?
I took some other measurements, and the only thing I found strange is output voltage from LT1054 - instead of -8.4V on pin 5 (9V minus voltage drop on D1), I only get around -8V. Because of the voltage drop over Q2, I have around -7.4V as the negative power supply for the circuit. I am unsure if it matters and can affect threshold control.
My build uses THAT4301 retrofit module. Few photos attached:
- red LED indicator on when threshold is set just to the point when voltage equals 0.6V
- red LED indicator off even there is no input signal
- general gut shot of my build
