Blend Knob Insertion Points (Hyped Fuzz)

[Slurp]

I wanted to add a Mask Audio blend to my Hyped Fuzz, and these were my insertion points. I am getting some uncontrollable squealing over 50% gain / vol, but it works at lower gain settings. I've verified that the pedal works correctly before installing the blend knob, and I tested the blend before I put it in, so I know it works.



Not sure if it oscillates because I made bad choices for where to put the insertion points?. I've heard people say in other threads that the Mask Audio Blend works fine with an Promethium Distortion without oscillation, so I assumed a Hyped Fuzz would also work with it!

If anyone has had success with any other types of DIY blend knobs on a Hyped Fuzz let me know. Thanks

 

[Feral Feline]

Have you tried having the return after R37?
ie between the output and the bypass.

 

[Slurp]

Have you tried having the return after R37?
ie between the output and the bypass.

I actually haven't tried anything else, since my first go at it was essentially a guess, and I wasn't sure if I was completely off base haha

If I'm understanding your suggestion - I would undo the cut I made at the level pot center terminal, then route the return to the output jack node (beside R37)? If that's correct, I'll give it a shot

 

[Feral Feline]

Yup. No idea if it'll work, but blend at the end avoids any influence Q4 may have had on the dry signal.

Also take a look at how the signal is inverted... a quick glance and I think the first time it gets inverted is at "scooped" and "full" — both those op-amps are inverting.

Gotta go, will check back later.

 

[Slurp]

Yup. No idea if it'll work, but blend at the end avoids any influence Q4 may have had on the dry signal.

Okay cool. And yeah I figured I'd have to poke around a bit since I heard high gain circuits are notorious for squealing with blends, appreciate the help

 

[Slurp]

Yup. No idea if it'll work, but blend at the end avoids any influence Q4 may have had on the dry signal.

Also take a look at how the signal is inverted... a quick glance and I think the first time it gets inverted is at "scooped" and "full" — both those op-amps are inverting.

Gotta go, will check back later.

Got around to giving it a shot today with your changes - still got the screeching! Hmm I'll have to keep messing with this

 

[Feral Feline]

Try Sw2.1 A2 for a re-entry point... but I think there's something else fundamentally wrong.

Take an audio probe and determine where the screech enters the equation; feedback loop problem, simply too much gain, short-circuit?

I haven't looked at the Mask Audio blender, but perhaps you need to stick the whole Hyped Fuzz in the Mask blender, rather than trying to apply the blender to the Hyped Fuzz — so, kinda like my first idea but with the Mask's send before the input of the Hyped Fuzz.

SIGNAL IN Mask split Clean BLEND MIXED-OUT
___________________________ Hyped Fuzz into


Okay, I took a peek at the Mask Blender, it's totally "Stick the Hyped Fuzz into the Mask's loop".

 

[Slurp]

Try Sw2.1 A2 for a re-entry point... but I think there's something else fundamentally wrong.

Take an audio probe and determine where the screech enters the equation; feedback loop problem, simply too much gain, short-circuit?

I haven't looked at the Mask Audio blender, but perhaps you need to stick the whole Hyped Fuzz in the Mask blender, rather than trying to apply the blender to the Hyped Fuzz — so, kinda like my first idea but with the Mask's send before the input of the Hyped Fuzz.

SIGNAL IN Mask split Clean BLEND MIXED-OUT
___________________________ Hyped Fuzz into


Okay, I took a peek at the Mask Blender, it's totally "Stick the Hyped Fuzz into the Mask's loop".

Ahhh that makes sense! Unfortunately I just tried it again, but it still had squealing I've been keeping the treble, bass, gain maxed out and the squealing only really stops at 25% volume (same as in every configuration of blender that I've tried). I'll try probing the Mask blend pcb and see if I screwed up any of the connections. One thing I did notice this time was that the clean signal was the lowest volume of all my attempts, which is strange

This time I tried these direct connections:
Input Jack -> Mask In
FX in -> Mask Send
FX out -> Mask Return
Output Jack -> Mask Out (Blended)

 

[Slurp]

Try Sw2.1 A2 for a re-entry point... but I think there's something else fundamentally wrong.

Take an audio probe and determine where the screech enters the equation; feedback loop problem, simply too much gain, short-circuit?

I haven't looked at the Mask Audio blender, but perhaps you need to stick the whole Hyped Fuzz in the Mask blender, rather than trying to apply the blender to the Hyped Fuzz — so, kinda like my first idea but with the Mask's send before the input of the Hyped Fuzz.

SIGNAL IN Mask split Clean BLEND MIXED-OUT
___________________________ Hyped Fuzz into


Okay, I took a peek at the Mask Blender, it's totally "Stick the Hyped Fuzz into the Mask's loop".

I was probing around for a bit, using a guitar loop on my phones output jack, while trying to pinpoint where the squealing was coming from... and I realized it had completely stopped squealing! The playback volume was maxed on my phone, and the pedal was max gain & volume

So I switched back to my guitar to try again and the squealing came back I even tried low output single coils. When I went back back to a loop on my phone, it's perfect. I am at a loss!

 

[Feral Feline]

Try putting a clean-boost at unity or a Boss pedal between your geetar and squeeling little piggy...


Most of all, try putting something OTHER than the Hyper Fuzz in the MAE's loop, as per the intended usage.

 

[Slurp]

You know what, I actually spoke too soon - I made a new testing clip that had some big gaps in the playing and the squealing is still there. Shoulda known better!

I tried a few Boss pedals before the squealer, didn't seem to help. I whipped up a DOD250 on a breadboard to try with the blend, and that also squeals so I am thinking this issue is on the blend board.

I made an SMD breakout for two J201's, they could be the culprit of why it's not working properly. I could swap them out for 2N5457 hmm... I might also just DIY a new blend circuit tomorrow, do you have any suggestions for a blend I could try out that suits this application? There seem to be quite a few types of blends kicking around

Thanks for all the help btw, really appreciate it. I will keep bashing my head on the wall until this works, gonna try again tomorrow

 

[Feral Feline]

Well, so far I've been of no help, so nothing new there!

For an alternative, I'd recommend JMK's Paralyzer, but it was out of stock last time I checked...


This might be of interest to you:

Adding a blend to a Promethium (HM-2)

Hey all, I've tried a few different things with this, and all have failed for one reason or another. I just want to add a blend to a Promethium. If I use the Promethium board alone (no blend mod), it sounds and works great. I've tried the GuitarPCB Buff n' Blend, but it oscillates. No...

forum.pedalpcb.com

 

[Slurp]

Well, so far I've been of no help, so nothing new there!

For an alternative, I'd recommend JMK's Paralyzer, but it was out of stock last time I checked...


This might be of interest to you:

Adding a blend to a Promethium (HM-2)

Hey all, I've tried a few different things with this, and all have failed for one reason or another. I just want to add a blend to a Promethium. If I use the Promethium board alone (no blend mod), it sounds and works great. I've tried the GuitarPCB Buff n' Blend, but it oscillates. No...

forum.pedalpcb.com

Honestly, just being able to bounce ideas around is very helpful to me. At the very least you're saving my wife from having to do a lot of head nodding hahaha

Thanks for linking that thread. I took a look at the JMK Paralyzer, but I am a little confused about what I'd do with the two loops. Of course one loop would be the FZ2 PCB in / out... Would the other loop just be input jack and output jack?

 

[Feral Feline]

You're lucky, my wife doesn't even nod anymore, unless it's off to sleep.

You could just hardwire the second loop together for an always on clean signal.

However, that'd be a waste! What I'd do is wire the second channel to a set of switching jacks. When nothing is plugged into the jacks, they act like a hard-wire connection and you've got your clean blend, but if you plug in something like a Flanger into the 2nd channel's jacks, you'll have a flanged signal to go parallel with your FZ-2. Why stop at flanging though? You could stick a whole other signal chain into the 2nd channel, a sub-octave > OD > tremolo or whatever you want.

If you add a stomper to the equation, you could turn on/off the loop and stomp between having a clean signal / whatever's-in-the-loop... in addition to having the FZ-2.

Parallel processing offers some really wild options.

But wait, there's more!

Have another loop going between the FZ-2 and the BLEND. Then you can process the FZ-2 with some EQ and a Green Ringer octave-up, into tremolo... combined with the channel 2's loop of Octave-down > OD > Tremolo > Flanger...

Hmmm I wonder if there's a way to sync up the tremolos so when the FZ-2 Octave-up>tremolo is ON the channel 2's tremolo is OFF and vice versa. Easy enough to sync the two tremolos if they're both optical, but I'm not sure how to have the one off while the other's on thing going. Hmmm something new for me to work on...

 

[Slurp]

I built up a Mad Box blend, similar to the one you suggested since I had all the parts (it's got two discrete TL072 loops).

It kinda worked? When I was probing around with the output jack both of the discreet loops worked totally fine, but the circuit would cut out after a few seconds of playing when I probed the blend. I have no idea why, it was a gradual ramp-out to silence. And then it "reset" if I probed the circuit input and I could hear the blend from the output node again before it fizzled out to silence a few seconds later.

So basically, I decided that I am done with trying to do a clean blend on an FZ2 I've got an HM2 on the docket next, and I will use that thread you sent me since people seemed to have good luck getting it to work with a Promethium.

For the FZ, I decided to use a low part-count JFET blend on a green ringer instead, and run that directly into the FZ2 FX input. I thought it would be cool since the boost mode can be used as an overdriven green ringer. I am okay with this compromise

 

[Feral Feline]

I wonder if the FZ-2 is charging up a cap, giving you sound and then as the cap drains away (to ground presumably?) away goes your sound, too.