synFUZZsizer

[artifus]

rather than a competition, how about some collaboration and cooperation?

forum project suggestion:

cmos 4000 modular guitar synFUZZsizer

think lunetta, craig a, tim e, nic collins, geofx and various other previously posted audio electronic projects

be good to keep it made up of:

simple, small, modular, expandable, interconnect-able boards/boxes
minimal component count
cheap commonly available parts

something like:

input buffer/splitter/driver
envelope detector/follower
fundamental extractor
fuzz
up
down
division
synthesis
lfo
vcf
vca
output mixer/buffer


4049      buffer/gain/fuzz/filter/lfo
40106    pwm/wave shaper/lfo
4077      oct up/pulse width/ring mod
4040      oct down
4046      tracker/synth/vco
4093      stutter/gate/strobe
4017      sequencer
4051      sequencer/waveshaper
555/556 frequency division/ugly faceness

it's all out there, just needs putting together.

if we each worked on separate modules of interest once agreed on certain control parameters, ie voltage, logic levels or what have you, something  beautiful could happen.

ideas? thoughts?

[R.G.]

Good idea. For some background, you might want to look a the FXBus at geofex, 4/19/2000. Not the same modules, but there may be some ideas there about standardization and signal flow, as well as standardizing (or at least localizing) the controls to be used, which gets to be an issue on any modular system.

[Tony Forestiere]

Good idea. For some background, you might want to look a the FXBus at geofex, 4/19/2000. Not the same modules, but there may be some ideas there about standardization and signal flow, as well as standardizing (or at least localizing) the controls to be used, which gets to be an issue on any modular system.

+ A BUNCH 
I have been digesting this for about 2 years. It makes perfect sense from a standardized model. The project link is hard to find, so here is the URL: http://www.geofex.com/Article_Folders/FXbus/fxbus.htm

[Earthscum]

I've actually been working along these lines myself, so I may have some to contribute... as a matter of fact, I'm working on my wood wah's circuit right now (well, procrastinating... need more coffee). It is a 4-pole filter, and works great. I just have to work out some build details, and a couple other things, and I'll throw it up here. I guess I'll have to double check that it works with UB's. Right now I am using OPA's, but all the stages are inverting, positive to ground, so I see no problems converting it over. Only thing is it may not be linear, but that's something we can work out here, right?

What voltages are we thinking of here? 9-volt friendly? Or wall supplied?

Modules for a single box? Or box to box to (box a and box b) to box, etc... pedalboard style?

I figure an "input box" (if going with the box to box idea) would need to be signal splitter, minimum. Probably be better to have wave shaping in, as well, with an effects loop, and dry signal outs (for envelope detection and mixing). I've thought a lot about this, lol. I have notes scattered all over the place with ideas for stuff like ADSR's, and wave folders (I thunked that one up on my own... then I came across a schematic for one. I was suprised at how close my concept was to a working one! Good me... lol)

I'm in on this one. I'm sitting on CD4007, 4011, 4013, 40106, 4017, 4046, 4049 (and 4050), 4066, 4070, 4093, and maybe a couple others.

[joelindsey]

I'm very interested. There's no shortage of awesome circuits out there I would love to build, but the thought of buying a switch and enclosure (and drilling it), wiring it all up stops me. Seems like a modular system would be so much easier in a lot of ways. Were you thinking a sort of modular synth approach to construction, with the modules being patched together?

[Earthscum]

Ok, procrastination got the best of me... here's what should work, as it does for me using OPA's. I'm actually using 10k's instead of 100k's, and a Jfet gain stage, but this is CMOS, right? If someone else doesn't beat me to it, I'll plug this in once I get my board cleared out.



Capacitors I figure should be about .0047 to .047uf.

Capacitor sets I've tried that worked good:

C1, C3, C5, C7 = .01 uF Cer.
C2, C4, C6, C8 = .1 uF Cer.

C1, C3 = .0068 uF Cer.
C2, C4, C5, C7 = .01 uF Cer.
C6, C8 = .1 uF Cer.

Currently:
C1, C3 = .0068 uF Cer.
C2, C4 = .01 uF Cer.
C5 = .01 uF Cer.
C6, C7 = .022 uF Poly.
C8 = .033 uF Poly.

The cap spreads are working better with the feedback I have going with the OPAs' +In pins, but without feedback, I think the best sound would be C (1, 3, 5, 7) = .0068 uF, and C (2, 4, 6, with .01 uF.

[artifus]

What voltages are we thinking of here? 9-volt friendly? Or wall supplied?

yes and yes. (though now i think of it maybe a 4.5v option to make use of old phone chargers would be useful/eco friendly?)

Modules for a single box? Or box to box to (box a and box b) to box, etc... pedalboard style?

yes and yes. pick and mix to create your own one trick pony or build a mammoth modular monster in one box.

I figure an "input box" (if going with the box to box idea) would need to be signal splitter, minimum.

this is where the thought needs to be put in and decisions made, i guess. my initial thought was a 4049 based fuzz box with send and blendable return - handy for going to and from breadboard to try out ideas with. but this thing is wide open and probably best left to the end user to decide upon.

Seems like a modular system would be so much easier in a lot of ways. Were you thinking a sort of modular synth approach to construction, with the modules being patched together?

i'm not sure i had a final finished product in mind as this could (hopefully) go in so many different directions with so many options available, just thought a thread on the subject to collect and share ideas would be useful.

the few cmos modules i've built so far have comfortably fit on a 10x10 stripboard. raw ingredient one chip wonders with just a few, if any, passive components expecting logic level in and sending logic level out running on 9 volts.

there are many ways to beat a dead horse when it comes to guitar sound sculpting but once squared up logic 1 is logic 1 and logic 0 is logic 0 and i'm just exploring what is possible within those limits at the moment. final tone shaping would be a matter of taste.

glad to see there's some interest, i'm looking forward to this.

[Earthscum]

I'm actually stoked on this. I even have some octal flip-flops I might dig back out for some kind of oddball module.

Oh yeah, this envelope circuit has been a good, reliable base for many projects:

[artifus]

Ok, procrastination got the best of me...

nice! fets could be replaced with ldrs. reminds me of http://folkurban.com/Site/GhostDance-702.html

i was just about to link to that envelope follower! also:

another led and r to ground for inverse envelope.

[Earthscum]

Very kewl!

Oh yeah, just to add something about the filter... I decided to use MPF102's because they have such a high IDSS. This means that instead of using them within a 2k-2M range for a full range sweep, they can be used from the 200R-200k range. I did this so I could reduce the resistance values in the feedback. It means larger caps, and more current, but less noise... and the 100k's have been acceptable to me in 4049 circuits so far. To get a bit more "oomf" out of the bottom end when the filter is swept down, the resistors can probably be bumped up to 220k's or so without adding too much more hiss.

Also, the bias/start frequency network is very very minimal. This is an area that definitely needs looked into, as well as an output buffer, probably.

ETA: Just remembered... when I first started my wah project, I had originally intended on trying 2 Q&D VCF's. and then 4. Somehow while populating my breadboard I decided to take the jfet approach instead. So, the Jfet might be able to be replaced with matched LED's and 10k resistors to CV (or, CV to a voltage follower to the 10k's).

[artifus]

thanks for the info.

Also, the bias/start frequency network is very very minimal. This is an area that definitely needs looked into

as well as an output buffer

buffering could be taken care of elsewhere, each module representing a basic idea?

[Earthscum]

thanks for the info.

Also, the bias/start frequency network is very very minimal. This is an area that definitely needs looked into

as well as an output buffer

buffering could be taken care of elsewhere, each module representing a basic idea?

Very true on the buffer part. As a matter of fact, when I threw the schem together, I left out the 6th inverter just out of habit of not using all 6 for audio processing. Filtered output would go to only a small handfull of options, unlike the trip the signal can take BEFORE filtering, and would probably need the buffer, but no inverters left for one. So, it makes me wonder, without wasting too many inverters, what kind of high performance buffer is there, or could be made? I mean, you could make a hex-buffer box easy enough, but I seem to remember seeing a couple that used 2 inverters in the feedback to do some filtering, and I remember the audio clip sounded exceptionally clean sounding. 3 inverters "wasted" if you build just a buffer isn't too bad, in my opinion... but using one inverter on a hex package just seems, well... like driving a OTR rig with a full load down the street to get smokes. 

[artifus]

3 inverters "wasted" if you build just a buffer isn't too bad, in my opinion... but using one inverter on a hex package just seems, well... like driving a OTR rig with a full load down the street to get smokes. 

i'm into squeezing as much out of each ic as possible too. i imagined the buffer board to also have a fuzz stage and/or squaring for logic and/or envelope detection. return buffer on same board?

[slacker]

This sounds like a great idea to me, I'm in

What voltages are we thinking of here? 9-volt friendly? Or wall supplied?

yes and yes. (though now i think of it maybe a 4.5v option to make use of old phone chargers would be useful/eco friendly?)

I like the idea of making it 4.5 or 5 volt, like you say loads of people will have suitable chargers lying around. The only problem I see with doing that is it makes it harder if you want to use opamps in the designs as the common ones won't work well on 5 volts. Or are we going to say no opamps?

[artifus]

Or are we going to say no opamps?

no rules, should be as open as possible, but personally i'll be sticking to cmos in this thread and trying to keep it to simple building blocks. how about cmos-ing the slacktave front end?

[R.G.]

Just as a personal observation, pay attention to how you package it. Packaging is a huge issue in modular systems.

Circuits are easy. Whether more than one ever gets built depends on how easy it is to package them up.

[Earthscum]

i'm into squeezing as much out of each ic as possible too. i imagined the buffer board to also have a fuzz stage and/or squaring for logic and/or envelope detection. return buffer on same board?

If I can find that schem for the buffer I was talking about, a box with stereo buffers would be pretty neat, except the possible crosstalk. I gotta go to a christmas party today, but I'll dig around and see what I have in my files... I may have saved it.

I'm into squeezing, as well. I had to do a layout for Anchovie's One Chip Chorus just because I knew I could make it smaller (and exactly for the reason here... I made it small so you could add it to a board before you etch if you want, or build it alone and stuff it inside something else).  http://www.diystompboxes.com/smfforum/index.php?topic=92872.msg811715#msg811715

[joelindsey]

I like the idea of making it 4.5 or 5 volt, like you say loads of people will have suitable chargers lying around. The only problem I see with doing that is it makes it harder if you want to use opamps in the designs as the common ones won't work well on 5 volts. Or are we going to say no opamps?

If 4.5/5V is decided upon, and one wishes to use op amps in their module, somebody could always build design bipolar power supply module.

[artifus]

...except the possible crosstalk

this is exactly the kinda stuff i need to brush up on and what i hope to learn from this project. full of great ideas, but i'm sure 'mother nature' - as r.g. would say - is bound to step in here and there and stomp all over my plans. another reason why i'm keen to avoid op amps, etc, here and stick to cmos - simplicity, low component count/cost and easy debugging. and what is learned here can hopefully be applied to later projects involving op amps and such rather than painting by numbers.

this thing ain't gonna sound pretty - tone hounds need not apply - but should be fun.

Just as a personal observation, pay attention to how you package it. Packaging is a huge issue in modular systems.

Circuits are easy. Whether more than one ever gets built depends on how easy it is to package them up.

as you may of guessed, i hadn't got that far yet, r.g.  - as i mentioned before, i have no definitive device/final product in mind beyond a basic 'driver' and 'receiver' between which the various modules could be hacked into allowing forumites to pick and choose and use in their own designs of as many modules as desired, be it a one box one trick pony, a many boxed modular monster or one box mammoth. i was originally going to limit myself to five ic's and call it the c05mos to present here but the idea was developing into a CMOnSter and keeping open ended seemed the best way to go. plus starting a thread on the subject may be just the incentive i need to get it done. there's nothing new here, i'm well aware that it's all been done before and that similar projects have been attempted in the past, it's just a bit of lofi fun and hopefully a learning experience. i haven't registered a domain name and opened an ebay shop just yet! i get what you're saying though - pots, jacks and switches are expensive. hmmm...

I'm very interested. There's no shortage of awesome circuits out there I would love to build, but the thought of buying a switch and enclosure (and drilling it), wiring it all up stops me. Seems like a modular system would be so much easier in a lot of ways. Were you thinking a sort of modular synth approach to construction, with the modules being patched together?

are you suggesting some kind of breadboard based inventobox™ module with jacks, switches and pots ready to rock? hmmm...

all i'm planning to do so far is to post some interesting sounding basic building block layouts (once i pretty them up) with brief explanation of function, link to relevant source/inspiration, datasheet, suggested component values, etc, as starting points for folks to breadboard and see what happens. sound samples may be useful too.

I gotta go to a christmas party today

have fun!

[egasimus]

...4007  vcf...?