a really really big fuzz

[crochambeau]

Just to confirm I understand what's happening here: I am to lift the center leg of SW2 and tie that to the Q3 side of R5?

No worries, if I'm going to be brutally honest, I've been too immersed in troubleshooting my own fucked up work to spend a WHOLE lot of time with this (for which I apologize). Switching the trannies around to swap collector and emitter sorted the first issue, and no harm befell the Ge so far as I know. I do have sockets, so it'll be easy enough to explore. I just got back home, I'll see what sort of damage I can do tonight on reassigning the switch (per my interpretation quoted)..

[Ben79]

Sorry here too. I sat down to mod it but got a bit lost and have been waiting for Curt and his skills to guide me in….it's his fault!

Got called up to go work away but I'm home today and will get on it. Looking forward to it, I love this eccentric machine.

[crochambeau]

waiting for Curt and his skills to guide me in….it's his fault!

OH GAWD, WE'RE ALL DOOMED!!!!!



Just kidding, I'll make good on it, or crash the plane into the mountain trying..



Really though, today. I will do the electronics adjustments today.

[eatyourguitar]

You guys are great. Im painting my new office today. I have no access to my files till then. I also failed to get everything done by my deadline. I feel your pain and share your joy. Pretty soon i can fire up the soldering iron and join the party!

[crochambeau]

Okay, I snipped the center leg of SW2 and tied it to the Q3 collector directly.

The switch does stuff now.
Dirt also reacts, it does not seem to make as big a splash as COMP, STAB, or GATE - though the controls are all HIGHLY interactive and will demand more exploring time.

Mine is also motorboating, but I have a lot of flying leads and haven't stuck it into the enclosure yet.

It lends itself to sputtery bitcrush (for lack of a better term) sounds well, you can dial in a "working man's fuzz" sound, but the balance is pretty particular to one end of the spectrum, whereas the controls really want to swing you over the edge. Reminds me sort of like taking a rickety old jalopy out onto the freeway, you're afraid the cars going to come apart underneath you, but all the controls are geared toward making it go faster. I mean that in a good way, I like the thing so far, need to house it proper and put it to some abuse.

My main complaint would be regarding the sculptability/intensity (needs more to balance out the rest of circuit) of the tone controls. "Bass" is also my goto to get self oscillation, I haven't plugged it into a proper big amp yet, but so far it doesn't seem like BASS is what it claims to be.

If your intent is to punch these out as kit type builds once optimization is complete, maybe situating a small garden of pad per hole or 3x1 pads in the area of the tone tuning would make hot rodders happier.. but honestly so far I'm glad I built it - thanks for throwing one my way and being understanding regarding the arc of time...

Good news on getting your bench situation near! I can't imagine living without one.

More soon, I intend on demoing it once I get a body on it..

[crochambeau]

Hi-Z control has the ability to completely dump the fuzz side of things, and the range seems relatively small (mind you, I've only a stock Stratocaster to test with so far). Pot travel is as follows full CCW = no fuzz, cracked CCW operates normally up through the range to full CW where I swear I can tell it sounds a little different but it might be like that time I thought I was hallucinating after taking a single aspirin.

I've plotted where the pots are going to sit in the case, time to house...

[eatyourguitar]

Well actually the Hi-Z control is working perfectly but you might want to add a resistor if it goes mute when fully CCW. If you have a really clean mic pre / DI then the Z would control brightness through intentional impedance mismatch via the control. It is something very obvious on a bright guitar aka the strat bridge and a bright clean amp with no fuzz. If we use 1MA then we might get to explore a bit more of the low pass side right before it goes clean and goes mute.

You said dirt control works. Does mud also work like another tone control? Or is it just the dirt you tested?

The bass control changes the frequency response and reactance (impedance) of the ac coupling between gain stages Q1 + Q2. There is a rather simple network of two caps and a resistor that creates a tone network. I have not done simulation in spice but i did build it and it worked great. It kinda moves the mid bump around. Its not like a tilt eq. I only had shitloads of sustain, feedback and motorboating with an amp. Try it with a mixer DI and headphones so the pickups and strings do not get excited from the output of the fuzz. It could be from all the flying wires but then that makes me wonder if the gain of the trannys is too high. You already have weak output passive single coils small signals goin in. Or going the other way, if the guitar signal is low, the user has no choice but to use more gain at the input and this can pickup noise from the flying wires where the output signal is in close proximity parrallel wires efficient induction.

[eatyourguitar]

If you have a sine generator or a youtube video sinewave 1KHz maybe try that and see where the motorboting is the worst on the controls. This could be useful to debug but im not sure if the problem is exasberated by wiring. It may be a personal endevour if only this one build is affected.

[eatyourguitar]

Try 470pf cap + 10k in series then put that thing on the lugs of the Z knob. That should make it completely unaffected at HI-Z and super muddy at low Z. This is my intention. We want to have some tone suck aka low pass aka make my fuzz a woolly mammoth or a perseus.

I may have a more complicated Z control comming soon. I think i need to do it like electro harmonix does these tone networks to ground on one pot. Needs two resistors, two caps and a pot. I should really draw a schematic for you.

At this point we could scrap the Z for a MFOS low pass filter TL072 but then we have no control of the actual input impedance.

[Ben79]

I'm now way out of my depth with all the electronics talk so I don't know how much more help I can be but this thing does have some amazing sounds in there.

So far I've only got pretty extreme sounds out of it but that's fine by me, mine's called the Overcompensator after all.

Octave down, blooming PWM sweeps, strange sounds that pop up every time you stop playing then go away. It seems wonderfully unstable and chaotic.

I don't yet have labels on my knobs so I don't even know what I'm changing half the time but it's almost more fun that way - no prejudice, just a wander into the unknown.

Just been playing with a glitchy, starved, gated sound with the clean blend on max.

It's a great massive thing for teasing out some new musical ideas I think.

Thanks Rob for including me in this and Curt for your help along the way and for your patience.

I WILL MAKE A VIDEO SOON



….trust me, you don't want to see inside. Despite the half mile of hook up wire in there, it's surprisingly quiet and only oscillates when you'd expect it to.

[crochambeau]

Awesome! I look forward to seeing/hearing yours.

Apologies on my spotty participation in the thread of late, only really posting here when coming up for air - so, I haven't spent ANY time troubleshooting..

You said dirt control works. Does mud also work like another tone control? Or is it just the dirt you tested?

Does that knob change names depending on the position of a switch?

I do have test gear, so feeding it signals at various frequencies/shapes/amplitudes and watching that on a scope is possible. I also might have been a bit drunk when I posted, so "motorboats like a motherfucker" might have been a touch embellished.

In all likelihood, I will be unable to spend much time on it in the next couple weeks, though I will try...

In summary, so far I feel like it's a solid design worth chasing, and I do like mine (even unfinished). The sheer quantity of panel controls might scare a few people off though. I think (and I hate to say this because I'm a grumpy old asshole) jack mounting the board is super smart in that wiring is kept to a minimum, at least so far as your weekend builder is concerned.

[eatyourguitar]

You said dirt control works. Does mud also work like another tone control? Or is it just the dirt you tested?

Does that knob change names depending on the position of a switch?

correct, dirt is diode clipping from collector to base. MUD is ac coupled negative feedback. another way to describe it is that MUD is a cap from collector to base. the cap reduces high frequencies by letting the high frequencies back down to the base with the same signal 180 out of phase. the two signals start canceling more and more as you approach the high notes on the guitar or the upper harmonics of a note. it is a brightness control that should in theory also reduce gain of the transistor and increase stability regardless of temperature, part tolerance, and component interaction. thats right out of a transistor handbook. stability in that sense means something completely different than zvex STAB which is actually just a starve knob on the power supply.

let me know if it has a functional brightness control with MUD and a distortion control with DIRT

thanks

[eatyourguitar]

already have 9 pots with pretty tight but not super tight space between that are holding the PCB in place and reducing the bulk of the DIY wiring. neither of you used the PCB mounted pots and I'm fine with that. but I think most DIY people do not have the desire or the proficiency to correctly wire 9 pots off board. if I have 5 people that want jack mounted PCB instead then I will gladly go design a new PCB for them right now. I will make whatever people want as long as they want to buy it and keep me going.

I think I'm pretty happy with this project so far. I need to build one of these for myself so I can just try it instead of asking about it. are there any other requests for new features?

[eatyourguitar]

bump for AUDIO/VIDEO anything?

[Ben79]

Made a quick video today.

Click my FB page in my sig and it's at the top of my feed. I think it shows you the crux of what the pedal likes to do which is to basically be unstable and mad. I think the secret for using it IS to leave the names off the controls and to tweak blindly.

It also does some nice modulating oscillation stuff and i've got it to do a slowed attack and produce something that sounds a lot like a thin sawtooth wave!

I plan to make a proper video next week with a mic - the sounds deserve it and I need practice making videos.