Trying to emulate TB303 sound

[Awazleon92]

Hello All,

I hope you got good summer holidays.
For a time, I don't have a technical/hardware issue. I'm just wondering how to emulate the TB303 sound with some Oakley modules.
I have in my case 2 VCO's, 1 LFO, 1 Noise/Filter, Multimix, TSL filter, VCF filter, 2 ADSR/VCA, 1 Dual VCA and one Sample/Slew.
Out of Oakley modules (sorry Tony ) I also have 1 ARP4072 Low pass filter and a JH Triple chorus.

I tried but never got something similar to the TB303.

Do you have some tricks or is it impossible ?
Any clue ?

Thx in advance
Tave a nice day

Pascal

[Synthbuilder]

Do you have some tricks or is it impossible ?

It is impossible to get anything other than a TB303 to exactly sound like a TB303. However, you can get close. How close depends on what you have at your disposal.

With the modules you have you're not going to get that close I'm afraid. But so long as your goal is to have fun then that doesn't matter.

First thing to get right is the notes you are playing. The TB-303 sequencer, although there is nothing special about the timing, does force one into creating TB303 sounding riffs. This can be demonstrated by controlling another synth with the CV/gate output of a TB303 and getting remarkably 303 sounding patterns. The MC-202 does something similar too.

So think about glides and accents when you program your sequence. Notes that don't belong to the key that you are playing in may help in getting a realistic pattern. Oddly, as one gets better at programming the 303's sequencer the less likely you'll create 'classic' sounding acid lines. I think a lot of of those classic acid patterns are 'happy accidents'.

On the TB303 a programmed accent does three things, changes the filter EG's decay time to its fastest, sweeps the filter cut-off with a simple envelope with a depth controlled by the resonance pot, and additionally blips the output VCA to produce a louder sound. This is not so easy to replicate on a small modular.

Glide is applied to legato notes only. (This isn't strictly true as all notes have glide applied for a very short time but the time that glide is applied is so short that it doesn't make a huge difference). It's a standard exponential glide circuit. The Oakley midiDAC uses a clone of the TB-303's glide circuit although you can change the glide time on the midiDAC. Glide time on a 303 is fixed and pretty short.

The classic 303 sound is usually overdriven somehow - quite often just by turning up the gain of a mixing desk so that it distorts. And the TB's diode ladder isn't the cleanest filter type so a clean filter like the 4072 or TSL may not do the job.

Use only one VCO on either square or sawtooth. The 303's square wave isn't perfect though (it changes shape with frequency) so you may wish to play with the pulse width a little to get it to sound right.

Tony

[Paradigm X]

Wow, funny, i was going to post something similar very soon.

Tony's already posted the bulk of it, im currently working out the accent side of things too. I reckon youll need a second AR or AD envelope and maybe a second vca? Theres tons of info about how it all works on the x0xb0x website too.

i use the x0xb0x sequencer which does naturally send out very 303 type patterns - the right gate length. But doesnt send slide information, this is dealt with in the x0x itself so you only get static notes out of the cv out.

i think this ultimately will help a lot to get authentic sounding acid, as tony rightly points out, ive used it to send cv to the sh09 and midi to the dominion1, and even midi to the blofeld, programmed in mono legato mode, and it sounds very acid. you can grab x0xb0xes quite cheap on ebay, and or build one, and theyre a great acid box anyway, a cv/gate converter, a dinsync converter and a great sequencer as well. Ive been hoping someone will make just the sequencer, all the files are open source, but beyond my skills by a long margin.

I use the Oakley VRG as a gated slew and it works brilliantly. ive bought a second to use for all the other functions, but not built yet. this allows you to add a slide when it receives a gate note. Using a second sequencer to control this is brilliant fun. Not sure if the sample/slew will do gated slews, not really used mine much

i have the slim vco, which is apparently roland inspired, and does very much sound like it. so perfect for this application.

i use the cota filter which is also very rolandy, perhaps not quite 303 tho, more like the 101 to my ears. but still very obviously roland.

but then of course you can go far beyond the standard 303 sound, more vcos, FM the filter (a standardish x0xb0x mod), add sub octaves (ive just picked up a second hand motm120 - or tony should make his tb3031 sub octave into a module !), phaser, distortion (just finishing the overdriveII too).

then of course there is the sadly discontinued TM3030 which is just perfect, much better than the x0xb0x imho. i bought Tonys old one so is as good as it gets!

happy to continue in this thread, im massively into acid, although sadly i have virtually non of the same modules as you. post some examples when you can, and ill try to post something too.

cheers, Ben

[Paradigm X]

some other useful info;

http://www.firstpr.com.au/rwi/dfish/303-unique.html
regarding accents

this part is particulalry interesting!

The real fun happens when you have multiple accented notes in
quick succession. Since the capacitor has not discharged
fully from the one before, the second and subsequent response
curves go *higher*:

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            *****                *                  ****    *
         ***     *****          *                       ****
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Human listeners - and probably a few furry quadrupeds - interpret this
output of increasingly high pitched audio signals as sounding like
the cry of a living creature becoming increasingly distressed,
apparently in response to quickly repeated bursts of stimulus.

Whole essays could develop from this, in terms of how a few simple
passive components in the TB-303 mimic the distress cry of a living,
sentient creature. This is especially important in the context of
the effect happening more as the filter's resonance is increased.
There could be speculation as to how this audio response to distress
evolved, both in nature and in the TB-303. From there, it is
relatively simple to postulate that humans and other intelligent
forms of life would evolve to develop an analagous emotional
response when hearing such sounds.

http://www.firstpr.com.au/rwi/dfish/303-slide.html
regarding slides

http://www.transistorsoundslabs.com/stepper-acid/
alternative 303 style sequencer, for eurorack tho.

[Awazleon92]

Guys,

Thx for your answers.
I already own 2 ADSR/VCA modules and one dual VCA.
I'm building now a SVCO module, so I'll do some tests within VCO and SVCO to hear the difference.
I forgot to mention that I have a BeatStep Pro as sequencer with glide option and a MidiDac.
Following your advices, let me do some experimentations and come back to you.

@Tony : any chance to get a remaining TM3030 pcb sleeping on a shelve or in a draw

Pascal

[Leverkusen]

I think the sequencer hints are pretty on spot, for the sound I most of the time try something beasty like the the diode ladder filter...

[Paradigm X]

well, i had a play last night, couldnt get very close to a 303 but very similar to a 101. the svco and cota combination is awesome.

that said i got loads of cool acid lines, far beyond what the little silver box can do.

i didnt try to replicate the accent function, not got enough modules to do so yet, only one adsr and the vrg is tied up for slides (tie, slide, geddit?)

In a perfect world Mr Allgood would take the x0xb0x sequencer, which is open source, and replace the analogue part with the tm3030 engine. if im dreaming...

ive actually got one tm3030 pcb left when he did the last run, which, when time and energy and skills allow, will try to do something like that. the x0xb0x pcb is cleverly done so the analogue and digitial parts are on opposite ends of the pcb - you can literally cut off the top half to make room for the tm3030. the pot spacing is different tho unfortunately. all a bit ot tho now.

cheers

[Synthbuilder]

any chance to get a remaining TM3030 pcb sleeping on a shelve or in a draw.

Sorry Pascal I have no PCBs left. The last one I had I actually built up myself.

I may yet revisit the TB303. Not quite sure how or when though.

Tony

[josaka]

we had a talk about this before.. ..something beyond a 303 would be a big mover I reckon.. similar the thomas white video but with a heavy overdrive and a thicker resonance....




I would be there ..

[Paradigm X]

IMHO, My preferences would be to either incorporate the x0b0x sequencer, which is open source, all eagle files freely available, multiple firmwares already developed etc with the tm3030 engine, or to design the filter but with the envelope/accent functions (via a gate input).

edit: fwiw, julian also made a 5u motm size panel for the x0xb0x. didnt have a modular at the time i got mine, but tempting now.



ok. enough hassling.

[Awazleon92]

So, I tried to do something. just a starting point nothing phenomenal

Could be to high in term of frequency. I have to move one Octave down.
But in all of case, this doesn't sound at all like a 303. I'm even far...

https://www.dropbox.com/s/wb6o480jg2iso ... 2.mp3?dl=0

I don't know how to post a sound file, so this is a Dropbox link. If somebody is owning another solution, I'll be happy to get it.

Have a nice day
Pascal

[Paradigm X]

hey

dropbox works fine, you get a player as well.

sounds really nice actually, but tbh not that close. its hard to help in terms of modular because im new to it all tbh but in terms of constructive criticism, i would suggest

yes its a bit high maybe, sounds a bit high pass filtered maybe?
gate length is a bit short and staccato, 303 is a bit longer and hence a bit smoother - also slide time could be a touch longer?
no accent is pretty obvious. maybe a gate to add a bit of volume on the vca and a bit of extra filter vc gain now and again? not sure howd youd do that, i use a little midi synced 8step sequencer and use a trigger from the 909 to step it. maybe the bsp will do that?

does sound very acid just not 100% 303.

i did try but carried away and went overboard, now got a great acid sound im reluctant to lose, but intrigued to try a pure 303 again.

i think were both a bit limited in our filters, the 303 filter is so distinctive. i cant stop hearing my old 101 in the cota. what filter was that btw the tsl or the arp?

cheers

[Awazleon92]

Salut,

I know it is far from the 303 but anyway, this is also a good exercise to better understand the Modular way...
I use 2 VCO for this sound, square wave.
One going through the TSL and the other going through the ARP. Then I summarize both using a Multimix then the ADSR/VCA to shape a bit the sound and I finish with a VCA gated by the Velocity signal.
This is with this trick that I try to emulate the accent. I'm able to modify the accent and the gate delay with the BSP. I can even get a slide.
I also have another ADSR which drive the CV/Frequency of each filter. In addition, the CV/Reso of the TSL is driven by the Velocity (like the final VCA)

It is obviously that it will be difficult to 100% emulate the TB, especially after reading the web pages you mentioned in your previous post. To achieve that, it would be necessary to build a dedicated module acting as the TB303 does or at least able to drive the filters and behaviours as the 303 does.

I'm building a SVCO-A to add to the other VCO's. Once finished, I'll do a trial with it.
In the mean time I pursue my investigations that is bringing a lot of fun

Have a nice day
Pascal

[Paradigm X]

cool well i made a recording of my best effort so far. still not very 303 tbh need another adsr at least. reminds me a lot of my old 101.

edit soryy signal chain was;
oakley svco
diy cp3 mixer
oakley cotafiter
oakley vcadsr-vca
slides by vrg
adsr also modulating cota



cheers
ben

https://soundcloud.com/llahj/oakley-modular-303ish

[AcdNrg]

some other useful info;

http://www.firstpr.com.au/rwi/dfish/303-unique.html
regarding accents

this part is particulalry interesting!

The real fun happens when you have multiple accented notes in
quick succession. Since the capacitor has not discharged
fully from the one before, the second and subsequent response
curves go *higher*:

Code: Select all

                                                             *****
                                       *****                    **     ***
                                    ***     ****              **           
                                  **            ****         *
            *****                *                  ****    *
         ***     *****          *                       ****
       **             *****    *
      *                    ****
     *                         
    *                          
   *                           

So how would one do this in eurorack?

Option 1: Get a WMD Javelin, because it´s directly built in. Which is nice, but lacks any control over the process, like: how fast triggers need to arrive, the speed with which signal level is fallin, the shape etc.

Option 2: Get a boatload of helper modules plus a CV controllable EG. And this is where I struggle with how to patch such a monster.


Available ingeedients: Stepper Acid, VCO, VCF
Javelin and MME are in the mail and hopefully arrive for the coming weekend.