9 knob fuzz

[EATyourGuitar]

schematic
https://farm4.staticflickr.com/3917/15168387878_43b7cc522c_o.gif

the switch should be DPDT ON-OFF-ON so you can go back to the stock fuzz factory. everything on here is designed so you can go back to the fuzz factory. I did not want to build something that could not replace my old 7 knob fuzz factory that I sold and ZVEX copied exactly 3 years ago. the output volume is doubled without adding noise from extra gain stages. the only thing I am a little unsure about are the values for C7 and C4. if you want to do the tone control like the official zvex 7 knob, you should leave tone pin1 disconnected or maybe just move the tone control to the output jack like a guitar. I am finishing up the pcb design right now if anyone is interested PM.

comments and suggestions welcome.

[knutolai]

Looks interesting! Will there be a demo do hear what all the different parameters dooo?

[amptramp]

Input impedance is quite low - you could add a buffer stage with a variable input resistor to give variable tone suck.  That will give you ten knobs.   

[mth5044]

Nice! lots of little parts and pieces to look at. Tons of subcircuit fun.

If I read correctly, ZVEX lifted one of your schematics for a pedal?

[EATyourGuitar]

Nice! lots of little parts and pieces to look at. Tons of subcircuit fun.

If I read correctly, ZVEX lifted one of your schematics for a pedal?

not really. I lifted 5 knobs from him and he lifted one from me. I posted all the details here and on the madbean forum. I even lifted my BASS knob from other designs that are much older. however I posted on this here forum that I regret not using a 6 position rotary switch for C1. although I never actually built it with a rotary, I can see that he has. the 7th knob was R6 in my 7knob fuzz factory. it never did much. he simply added a guitar tone cap on a pot and connected a footswitch upgraded the price to $399.

[EATyourGuitar]

Input impedance is quite low - you could add a buffer stage with a variable input resistor to give variable tone suck.  That will give you ten knobs.   

I'm having trouble seeing it in my head. would it be a non-inverting opamp with a variable shunt 100KB?

[joegagan]

not to get too technical, but i had a phone conversation with zvex in 2003 wherein i extolled the virtues of adding a fat knob to the fuzz factory. what year was your schematic?

i am not taking any credit whatsoever, i am very sure that hundreds of people suggested this mod to him besides me.

[joegagan]

^^ it was the exact mod in your schematic, give or take a cap value difference of a little bit.

[EATyourGuitar]

not to get too technical, but i had a phone conversation with zvex in 2003 wherein i extolled the virtues of adding a fat knob to the fuzz factory. what year was your schematic?

i am not taking any credit whatsoever, i am very sure that hundreds of people suggested this mod to him besides me.

you are right. these are basic and obvious modifications and there are many pedal builders around the globe. the BASS control was suggested to me by someone on this forum. I have only been building pedals for 4 years so anything that happened in 2003 is way before my time. from my point of view zvex was happy with 5 knobs for many years and only after I posted a 7 knob fuzz factory to ebay and these forums did he start building his with the exact 6 position rotary switch mod I talked about. I just think it is possible that he reads the forums and I may have inspired him on those two points. probably mad at myself that I never pursued making 7 knob fuzz factories as a career even though I thought of it first. I posted this schematic to give it away. learning is important.

[therecordingart]

If someone wants to provide me with an Eagle file or Gerbers I can whip up a batch of boards on my CNC. Disclaimer: I'm just offering to give back to the community...not looking to profit off of you guys or take the "Y" out of DIY. The offer is out there...PM me if interested.

[therecordingart]

Input impedance is quite low - you could add a buffer stage with a variable input resistor to give variable tone suck.  That will give you ten knobs.  

I was thinking of putting a buffer on the input followed by the AMZ pickup simulator (http://www.muzique.com/lab/pickups.htm). I've tried it on one of the Fuzz Factory boxes I've built and it worked great with very little change in "tone".

[amptramp]

Input impedance is quite low - you could add a buffer stage with a variable input resistor to give variable tone suck.  That will give you ten knobs.  

I was thinking of putting a buffer on the input followed by the AMZ pickup simulator (http://www.muzique.com/lab/pickups.htm). I've tried it on one of the Fuzz Factory boxes I've built and it worked great with very little change in "tone".

I was thinking of a non-inverting op amp unity gain stage with the resistor from the non-inverting input to ground or Vcc/2 made variable so that the guitar could be loaded down to whatever level of tone suck was required.  1 megohm or more would be adequate for the pot but there should be some series resistance just to make sure you can't accidentally short the input signal.

[kingswayguitar]

Looks interesting! Will there be a demo do hear what all the different parameters dooo?

i second that

[EATyourGuitar]

schematic
https://farm3.staticflickr.com/2945/15182634869_150ac7e396_o.gif

updated it for you per your suggestion. you can remove the input cap if you use a charge pump to isolate the supply and reference all your jack sleeves to VB. for battery operation you can eliminate the input cap by referencing all your jack sleeve to VB and have a dedicated power switch for the battery. you can not use a stereo jack to switch power if you reference your jack sleeve from VB.

I had an extra opamp so I threw in the clean blend. I could have made some better filters with the opamp but then I would probably taken away the other filters that I added and that would be less knobs.

[EATyourGuitar]

corrected some errors in the schematic
https://farm3.staticflickr.com/2945/15182634869_bd6bb1258f_o.gif

[EATyourGuitar]

totally serious about building 11 and maybe 13 knobs on a fuzz pedal. I found my box.

http://www.mouser.com/ProductDetail/Bud-Industries/KB-13200/?qs=%2fha2pyFaduhs3%252bKy0iRHtpFRWx5e6AuCD3Z0yvzSkOg%3d

[mth5044]

Hammond have similar enclosure for cheaper. I used one a while ago for a bigger effect and it's pretty nice. Similar to those Lovetone pedals.

[EATyourGuitar]

can you tell me the hammond part number you used? I actually don't like the shape of lovetone as much as this LMB

[EATyourGuitar]

I will have two extra pcb's from oshpark pm if interested.

[antonis]

I will have two extra pcb's from oshpark pm if interested.

Propably you use the entire polygon for GND but there are also some discrepancies between schematic and PCB..