My second Muzzle is worse than the first?

[Elijah-Baley]

Hello,
I built a few years ago the Muzzle for a friend. I was really impressed by it! After I built it I test it with my friend: I used its TU-2 to split the signal, used the Input key and put the pedal in the loop effect. The 4 cable method. I tried the distortion channel of the amp but even with a DIY Triple Wreck in front of the amp.
This noise gate was incredible: zero hum and no loss of sustain or attack, and it didn't cut the feedback. And bypassing the Triple Wreck the clean was totally intact. Indeed we thought that this noise gate can be always on with no problem.

(Now I'm using some different gear: tube amp, a DIY Revv G4 and a DIY buffered splitter.)
This second Muzzle (the only difference is the new triplet smd chip) is not fully convincing. If I rise up the threshold enough to decrease a bit of hum I start to lose sustain and attack. I lose volume to decay of the note, it blocks the feedback. And it ruins my clean sound when I bypass the distortion.
I have to choice between still much hum or too gated sound.
What's happen to this circuit?

 

[Robert]

A couple people have reported issues like this and the only thing that could be to blame is a defective 4305 IC on the 4305 module.

I've sent replacements (and exchanged for the defective modules) a couple times and so far have not received a single module that was defective. Once I receive them they always behave exactly like the original THAT4301 through-hole IC, so I am at a loss as to what is actually going on here.

 

[Elijah-Baley]

I built the Muzzle with a kit by Musikding. What can I do now? Should I contact Musikding?

 

[Robert]

I built the Muzzle with a kit by Musikding. What can I do now? Should I contact Musikding?

Contact Musikding for a replacement 4305 module. If they give you any problems (I don't expect they will) have them contact me, I'll make sure they get a replacement. Worst case scenario I can send you one directly but I think you'll get it much faster from them.

 

[Elijah-Baley]

Thank you!
I contacted them and I'm waiting their answers.

 

[Elijah-Baley]

I still have trouble with this PCB (I received a new PCB from Musikding, but not a new THAT chip! I still didn't ask why).
I tested the circuit with the a Bogner amp of my friend, and it seems work better, or even fine, I could say.
With my Laney LC50, instead, it gates noise and sound at the same time, with the circuit is in the loop effect. And it is worst if I use Key input after a splitter.

Did you ever heard that the Fortin Zuul (or other noise gate) works bad with some amp?

 

[Elijah-Baley]

Can I have the voltage of the Muzzle's ICs, please?
I think on my build the transistors voltage have sense, while the IC TL072 and the THTAT combo no much. Ground -9v and 9v seems ok, but most of the other pins show voltage close to 0.00v.
My PCB sounds, it seems work nice in the pedal chain, but in the loop effect it gates the signal heavily decreasing volume. (I just tried with my other amp, a Crate, but it works bad like my Laney). Probably the effect loop of my friend's amp work differently.

 

[Elijah-Baley]

I built it again: new PCB and new THAT4301 RetroFit Module and all new parts from Musikding.
But it works bad in a identical way of the first built. So I'm pretty sure I didn't make any mistake on the board. I'm following all the method in the Fortin Zuul manual to insert it in the pedal chain, I tried every method, more or less every method works not so well.
It gates too much: noise and sound, the dynamic si totally compromised.

My first built, I remember, was awesome, with the key input it was transparent even with the distortion bypassed, I thought it is always on pedal.

https://cdn.shopify.com/s/files/1/0607/5115/1331/files/FORTIN_blackzuul_2023_manual.pdf?v=11518836023399736368

Orientation of transistors, ICs, diodes and electrolytic caps are ok. (I'm looking at pictures of PCB's other users).
I measured one by one the value of the resistors before to solder. Even all the other caps value are correct.
The 25k Linear Pot is ok, too.
Input jacks directly on IN (used for the input guitar or Send in the loop FX's amp) and Out (to input amp or Return of the loop FX's amp) on the board (without footswitch) I jumperd the GND and SW on the PCB to give ground to the LED, that it works fine.
The key input... I think it's ok. The switch on it works, and the tip (NOT switched) goes in the first 1uF cap in the upper left corner, that 1uF goes in the Base of Q1.
I built the splitter I'm using, based on this: https://paulinthelab.blogspot.com/2012/04/buffered-y-splitter-veroboard.html.

 

[micmac]

Hi Elijah,

I just finished a Musikding kit Muzzle as well. It seems to work fine. Wired up the KEY passthrough as per build doc, but it was really noisy. I think because my power supply is isolated. So I connected the sleeves of the KEYs (slanted corners) together with a cable, which sorted this out.

I took the IC voltages that you requested.

IC1 LT1054

8.99 4.72 0 -4.00 -8.50 2.54 1.44 8.98

IC2 THAT4301

0 -2.62 0 -0.13 -0.13 0 -0.12 0 0 -8.41 8.98 0 0 -0.12 -0.12 0 0 0.99 0 0

IC3 TL072

0 0 0 -8.41 0 0 0 8.99

I'll attach a pic, too. The 560n cap seems to be missing, but it's actually underneath the PCB because I couldn't fit it on top in between the other two caps.

Hope it helps!

Best regards,
Sepp

 

[micmac]

Yesterday I tested with pedal chain only, Muzzle key passthrough between Treble Booster and dirt, then Muzzle input/output after Delay and then into the amp. This morning I put Chorus and Delay into the loop of my Marshall Studio Classic and then connected the Muzzle input to Delay output and Muzzle output to FX Return (key passthrough position unchanged compared to yesterday). This also seems to work fine.

 

[Elijah-Baley]

Your voltage measurements look very close to mine, I guess. I'll check the voltage of my PCB soon.

I'm connecting the PCB following the Fortin Zuul's manual. I expected more especially from the 4 cables method with Input Key and Loop FX.

What happens if you bypass the distortion getting a clean sound, but with the Muzzle actived? I remember the Muzzle built for a friend of mine didn't gate the clean sound, and it was very transparent.

 

[micmac]

I checked the manual for the Fortin Zuul "Blackout" from Fortin website. I have a Musikding Buffered Splitter so I cabled everything up like on page 2 of the manual, the first example ("4 Cable Method - With FX Loop"). So the Muzzle's left side jack was not connected. It didn't matter if the distortion pedal was on or in bypass, the gating effect of the Muzzle turned on once the input signal (from the splitter) dropped below the threshold. That was also my expectation because the distortion pedal is not visible for the Muzzle, because it's connected the the 2nd splitter output and not to the KEY In of the Muzzle.

 

[Elijah-Baley]

So your clean sound is save and not gated? Did I understand?

 

[micmac]

No, that's not what I said (maybe I wasn't clear enough). Both my clean sound and distorted sound get gated the same way.

I reread your first post above. About the first Muzzle you built for your friend you wrote: "zero hum and no loss of sustain or attack, and it didn't cut the feedback." For me the feedback is cut when the Muzzle's gate kicks in.

Maybe when you tested your first Muzzle you put the Threshold too high and the gate was not activated at all when the guitar signal went low. So Muzzle wasn't gating and you heard the feedback. Just an idea.

 

[Elijah-Baley]

My first Muzzle (original THAT chip, no smd), I remember, with the 4 Cable Method, I set the Threshold enough to cut the excessive noise of the distortion perdal (DIY Triple Wreck), but when I bypass the distortion the clean was fine.
I hope to find my friend and try that pedal.

 

[Moltenmetalburn]

A couple people have reported issues like this and the only thing that could be to blame is a defective 4305 IC on the 4305 module.

I've sent replacements (and exchanged for the defective modules) a couple times and so far have not received a single module that was defective. Once I receive them they always behave exactly like the original THAT4301 through-hole IC, so I am at a loss as to what is actually going on here.

Im having this with my new pcb. Tried everything possible reseated, cleaned all pins and flux, even swapped the ne5532 out all with no change.

The retrofit pcb I have recieved is useless.

If you set it high enough to gate the noise it gates ALL signal. Set it low enough to pass signal and it allows ALL noise to pass. Tested in four working builds all the same. I still have a dozen new 4301 chips and all of them work without issue in any build.

Was there specific pcb revision needed? My boards are from before the chip shortage.


Otherwise a complete waste of my time and money.

 

[Elijah-Baley]

I still didn't solve my problem, exactly that you described:

If you set it high enough to gate the noise it gates ALL signal. Set it low enough to pass signal and it allows ALL noise to pass.

I was going to finished up my build putting the PCB into the box anyway, because I thought the issue was caused by the loop effect of my Laney LC50 (I heard somthing like that with a Mesa, I guess).
But after the last comment I have doubts, again.
I repeat that Musikding had sent to me a second Retrofit PCB, but both work bad in equal way.

I mentioned my Crate early. My first Muzzle (I don't have it anymore) worked wonderfully with it, I didn't have the Laney.
I can't test this new Muzzle build with the Retrofit PCB on my the Crate amp like I did in the past because that amp is now defective. I have to use a preamp pedal and go in the power amp. So I placed the Muzzle between the preamp pedal and the power amp of the Crate, like a loop effect. Using or not using the Key input, I had the same identical issue with the Laney. (I had the worst effect with the Muzzle in the loop effect.)

This is, actually, another clue that the two Retrofit PCBs I have could be both bad. I tried to ignored it, but...
If I can get back my first Muzzle I'll try the old no smd 4301 chip.

 

[ChrsGuit]

Hello,
I built a few years ago the Muzzle for a friend. I was really impressed by it! After I built it I test it with my friend: I used its TU-2 to split the signal, used the Input key and put the pedal in the loop effect. The 4 cable method. I tried the distortion channel of the amp but even with a DIY Triple Wreck in front of the amp.
This noise gate was incredible: zero hum and no loss of sustain or attack, and it didn't cut the feedback. And bypassing the Triple Wreck the clean was totally intact. Indeed we thought that this noise gate can be always on with no problem.

(Now I'm using some different gear: tube amp, a DIY Revv G4 and a DIY buffered splitter.)
This second Muzzle (the only difference is the new triplet smd chip) is not fully convincing. If I rise up the threshold enough to decrease a bit of hum I start to lose sustain and attack. I lose volume to decay of the note, it blocks the feedback. And it ruins my clean sound when I bypass the distortion.
I have to choice between still much hum or too gated sound.
What's happen to this circuit?

You mentioned In the first comment you used it in the chain post TU-2 Tuner and a buffered splitter...
Reason I say that is that I've owned some pedals that reacted negatively with the Tu-2 or other buffered effects/tuners, etc... Buffered Bypass can adversely influence the signal... You see it in Crybaby wahs as well...
In my experience it was with a Rangemaster clone with Germanium transistors, which would get really loud and sound like an ice-pick when placed after a buffered bypass tuner...I've heard many others have similar issues with fuzz pedals, etc... Just wondering if (this being a noise gate), the buffered splitter is doing something similar... getting an altered input where it needs to be THE FIRST in the chain and recievethe full guitar signal...
I'm just taking a shot in the dark here, but it might be worth trying to use ONLY the pedal and nothing else in the chain and then add the rest back into the chain til you find the culprit...
Hopefully that can eliminate any issues...

 

[ChrsGuit]

I still didn't solve my problem, exactly that you described:

I was going to finished up my build putting the PCB into the box anyway, because I thought the issue was caused by the loop effect of my Laney LC50 (I heard somthing like that with a Mesa, I guess).
But after the last comment I have doubts, again.
I repeat that Musikding had sent to me a second Retrofit PCB, but both work bad in equal way.

I mentioned my Crate early. My first Muzzle (I don't have it anymore) worked wonderfully with it, I didn't have the Laney.
I can't test this new Muzzle build with the Retrofit PCB on my the Crate amp like I did in the past because that amp is now defective. I have to use a preamp pedal and go in the power amp. So I placed the Muzzle between the preamp pedal and the power amp of the Crate, like a loop effect. Using or not using the Key input, I had the same identical issue with the Laney. (I had the worst effect with the Muzzle in the loop effect.)

This is, actually, another clue that the two Retrofit PCBs I have could be both bad. I tried to ignored it, but...
If I can get back my first Muzzle I'll try the old no smd 4301 chip.

In other words, try it straight into the amp with nothing else and go from there...

 

[Elijah-Baley]

I'm sure enough the problem is not the buffer in front, TU-2 or my DIY buffered splitter (op-amp based).
This pedal needs a splitter to use the key input. I heard if it's a buffered splitter is even better. The Muzzle is a replica of the Fortin Zuul, and the Fortin has a pair of buffered splitter box «perfect companion» for the Zuul pedal.

Indeed, my first good Muzzle, the one with the bigger old chip 4301 work fine with my friend's TU-2.

And the pedal works bad even without the use of the splitter.

I'm still think the problem is in the chip.