Bass fuzz-wah for synthy sound - any suggestions?

[anotherjim]

Does anybody know of any designs that can get close to Prodigy/Daft Punk etc mono synth sounds with a bass guitar?

[antonis]

Haven't Tom dealt with that (yet)..??

[bool]

IIRC there was something like that in old line6 basspods (rackmounts).

[DIY Bass]

Some of the Boss synth pedals are probably a place to start.  I can get some bass synth sounds out of my old Boss GT-6B.  That is some hard core digital stuff though.  The new synth pedal sounds pretty good - but again not DIY by a long shot.

[anotherjim]

Well, some of those recent bass synth pedals ought to do it -  you'd think. All the demos I've found suck. Mostly because the demonstrators seem incapable of adjusting their technique to suit or want to be Joe Zawinul, not that anything's wrong with Joe, just not the direction I'm interested in.

[Jubz]

Hi.

You have countless threads about synthy bass guitar on talkbass. The gated fuzz /analog octave down/enveloppe filter combo is a good place to start.

Some awesome videos. The TAFM seems very good at synthy fuzz and the schematic is published. Same for the boss OC2.

https://www.youtube.com/watch?v=-UcSkfyVij8

https://www.youtube.com/watch?v=b8qq3eCq8vw

[Jubz]

Or the new source audio C4 looks awesome. But it is digital.

https://www.youtube.com/watch?v=6Onh9EGHFow&t=76s

[Josh?]

I haven't actually built a physical envelope filter yet, but I've done a ton of stuff like this in https://supercollider.github.io/, which y'all should definitely check out, so here goes:

You'll definitely want a resonant low pass filter instead of the bandpass filters that are common in a lot of designs for guitar/bass. You'll probably also want control over the attack and especially decay of the envelope, to set these as short and stabby or drawn out as you like. Lastly, almost all of these synth basslines are built by feeding a saw or square wave through the filter, and any method of getting similar waveforms out of a stringed instrument, whether that's fuzz or an actual synth pedal (which I personally would recommend), will destroy the dynamic range of your instrument. Therefore, you should probably build a send/return loop into your pedal so that you can get an envelope from your dry signal, send that to whatever fuzz/synth effects you want, then bring it back through the envelope.

Also, check out this guy's demos, he leans a bit into jazzier playing sometimes, but also has great synth sounds: http://www.youtube.com/watch?v=mu9zVeDBIAI

[Fancy Lime]

So What Cha What Cha What Cha Want? To quote the Beastie Boys.

Expression pedal control? Envelope control? How crazy do you want it?

If I wanted to design something like that, I might be tempted to use a 4th order resonant low pass, envelop controlled, with a fairly simple fuzz (Bazz Fuss, a single Big Muff clipping stage, or an opamp Muff Fuzz) in before the filter (but obviously after the side chain split). Or two 2nd order resonant low pass filters with a clipping stage between them (I would use two filters from the Quackmire and control them with the same envelope follower: https://www.diystompboxes.com/smfforum/index.php?topic=119101.20). Or a diode ladder filter that is driven way the funk into clipping. Ah, these things are fun.

Andy

[anotherjim]

I don't think I need an octave down which for some reason, most of those videos do. I'm looking for a lead synth tone, although it's not often played in a high register. My 5 string bass has a high C instead of a low B for this kind of work. The octavers just make it far too fat and muddy for the job. The bass is "stereo", so the neck pickup is going to be clean and deep when I want that.

I agree that the fundamental tone I need is saw or pulse and in the latter case, maybe a little envelope pwm happening. Usually at least 2 VCO's with a bit of detune or a full 5th is used. However, for DIY its probably going to have to be some kind of fuzz front end.

LFO isn't needed. Never to the filter and vibrato & pitch bend comes via the fingers.

Filter is definitely low pass - a little resonance but not too funk-squelchy. Envelope to volume needs to go from snappy to a short but noticeably smoothed attack. Envelope to filter has a fast to short attack and a moderate rate of decay to let you hear a harmonic sweep down without too much wow/wah. The filter envelope might just be best done with an expression pedal, but envelope from the bass dry signal ought to be possible.

[bluebunny]

I was gonna suggest have a play with the Boss SY-300.  I use mine for bass, but tend to have my actual bass high in the mix, a fair bit of modulation (80s! yay!), and not too much synth.  But it will go bonkers totally-synth.

That was what I was gonna suggest.  But all I really wanted to say was thanks for the vid.  Keef - what a bloke (and what a song).   

[Kevin Mitchell]

Are we not talking about the Micro Synthesizer?


-KM

[Fancy Lime]

Hi Jim,

I hate to be tooting my own horn but I really think you might want to give the Quackmire a go. Small and easy build and, if you don't insist on the utmost sweep range and quackiness (which you seem not to), fairly tolerant as to what vactrol you use. Add a loop after the input buffer, before the filter section (don't forget that the filter needs to be separately biased if there is a DC decoupling cap between buffer and filter), and stick your favourit fuzz in the loop. Be sure to use the 1.1 schematic:
https://postimg.cc/phPkWkNH
and play with the cap values at the Mode switch for faster or slower attack and decay. Forum members and awesome people rankot and sverien made a PCB layout and a bread-board layout, respecivtely:
https://www.diystompboxes.com/smfforum/index.php?topic=119101.msg1145200#msg1145200
https://www.diystompboxes.com/smfforum/index.php?topic=119101.msg1146320#msg1146320
Soundsample (clean) here:
https://www.aronnelson.com/DIYFiles/up/Quackmire.mp3

If you want more intricate envelope controls, have a look at this thing:
https://www.diystompboxes.com/smfforum/index.php?topic=118966.msg1108974#msg1108974

The two circuits can easily be mixed and matched, if you like. By adjusting the ratio of the caps in the filter, you get a wide rage of sounds from tame to crazy-quack and you can easily calculate the result because it's just a regular old Plumbus Sallen-Key. For the wave shape, I would advise going into the filter with a square(-ish) wave. The low pass filter will then shape it into anything from a sine wave to a square wave, controlled by the envelope. Going into an envelope controlled low pass with a triangle will probably end up on the boring side. So any decent fuzz should get you in the right ball park. And by having the fuzz in a loop, you can easily swap it for another and see what sticks.

Just my thoughts, though, albeit stemming from a similar place originally. Also: have a look through Tim Escobedo's Circuit Snippets. He has some great simple wah and fuzz circuits that should contain something for everybody.

Please share the result, when it's done. I love this type of effect, it's just sooo much fun to play and tinker with. Cheers,
Andy

[anotherjim]

This is the most promising of the commercial synth pedals I've found so far - but that may be because the demonstrator is actually playing it like a synth pedal and getting closer to what I'm looking for. There's only a little of it played from a bass and there is too much top-end fizz. The monophonic lines sound sweet. The formant mode is a bonus - pretty cool I thought.
Note the price of those things - hard to beat with diy?

[sergiomr706]

https://www.youtube.com/watch?v=Ovy-p5kO5r8
This for me sounds really synth like at some settings and this one too, https://www.youtube.com/watch?v=68--Rh43d4c
both have schematics available, being the first being sold as a diy project,
At the other forum if memory serves me well I saw a bass balls that was modded to be used foot controlled as a wah, and I believe that pink jimi photon had a stripboard made for that. I would swear that Smack my bitch up starts with something like a guitar being played through a bass balls, but that s another story, you know you were talking about bass, but for me the bass balls always sounded good with my bass despite not being a LPF,  and I remember about someone getting acid synth bass tone alike, with a Bassballs foot controlled , an MS20 filter style and a gated fuzz, I think it was a mammoth. Something to try maybe.   https://www.youtube.com/watch?v=VgyJ8QsZiiE  I was listening to this a pair of days ago, and to me it could help sound synthy too, but maybe my idea of synth is a little dirty, and it has schematics available too.  https://www.youtube.com/watch?v=BgjtX5GmonE  brown dog and agent 00Funk together sounds great too to me, but 00Funk has a bad reputation about their knobs being hard to dial and recreate your sound again and that the interaction is bigger than desiderable, maybe the envelope detector could be tweaked a little to avoid this interaction.
Hope it helps

[Fancy Lime]

This is the most promising of the commercial synth pedals I've found so far - but that may be because the demonstrator is actually playing it like a synth pedal and getting closer to what I'm looking for. There's only a little of it played from a bass and there is too much top-end fizz. The monophonic lines sound sweet. The formant mode is a bonus - pretty cool I thought.
Note the price of those things - hard to beat with diy?

I say: If a commercial pedal does what you want and is not unreasonably expensive, buy that one. If there is no benefit in DIYing it in terms of (subjectively) better sound or something you wish to learn along the way, it's probably not worth your time and effort. When I find a pedal that does exactly what O want, I don't bother cloning it. My time is generally more valuable to me than money. I find DIYing really makes the most sense if you want to build soemthing uniquely your own, tailored to your own particular, peculiar, weird taste. Or the thing that makes the sound you really really want has been out of production for half a century.

BTW: the "formant" mode does sound fantastic. Now *I* want to know how to do *that*! Any clue anyone? I'm guessing the Dirty Robot is digital, so vocal sounds are just as easy to produce as anything else, but how to do that with analog filters? Or more precisely: What *is* that sound even? Sounds like it could be a filter changing Q and frequency simultaneously or several filters moving in different directions. If anyone can tell me what filter characteristics to look for or point me to an analysis, I promise this sort of thing is going to be my next project!

Andy

[ElectricDruid]

You can get "formant" sounds by using oscillator sync techniques - reseting the waveform to the beginning at a different rate to the length of the actual waveform. This produces peaks in the response that are related to the oscillator's "natural" rate, whereas the fundamental frequency is determined by the reset rate. This is the same thing done by "hard sync" in analog oscillators, but its much more versatile if you can do it with other wave shapes. I've had fun playing with it with digital generated sine and sine+octave type waveforms, for example. At one point I was playing with a "vocal oscillator" that generated the five (broad generalisation, but close enough) formants that identify human vowel sounds. That used several sine oscillators all being reset together. There are other synthesis techniques in the literature that I stole (sorry, "researched") ideas from, VOSIM and similar, that do this type of stuff.

Tom

[Fancy Lime]

You can get "formant" sounds by using oscillator sync techniques - reseting the waveform to the beginning at a different rate to the length of the actual waveform. This produces peaks in the response that are related to the oscillator's "natural" rate, whereas the fundamental frequency is determined by the reset rate. This is the same thing done by "hard sync" in analog oscillators, but its much more versatile if you can do it with other wave shapes. I've had fun playing with it with digital generated sine and sine+octave type waveforms, for example. At one point I was playing with a "vocal oscillator" that generated the five (broad generalisation, but close enough) formants that identify human vowel sounds. That used several sine oscillators all being reset together. There are other synthesis techniques in the literature that I stole (sorry, "researched") ideas from, VOSIM and similar, that do this type of stuff.

Tom

Hi Tom,

huhh... I see. That makes it more of a modulation than a filter effect, doesn't it? Difficult to do analog with a guitar signal. I smell some possible options by controlling a BBD with a superposition of the envelope and the actual audio signal (after fundamental extraction), but this needs more thought. There may be some edge detectors and frequency-voltage converters in there.

Thanks,
Andy

[anotherjim]

Parasit Studio "Sentient Machine" uses counter swept filters for a vowel effect.
https://www.parasitstudio.se/sentientmachine.html
This is LFO driven and the vowel sound happens when the filters cross to create the formant.

[bool]

Imho you need something fuzzy to feed a filter first...