How to create a CR-78 snare drum in VM?

[martin17]

Due to the current situation I have tried to recreate a snare drum that is supposed to sound like the Roland CR-78. Unfortunately, my version only sounds like a snappy TR-808 snare. Does anyone know the secret of the CR-78 snare drum?

CR-78 Snare 1.jpg (188.39 KiB) Viewed 669 times

[ColinP]

I don't know about the specifics of the CR-78 but the excellent work of Gordon Reid is always worth a look when trying to do this kind of thing...

https://www.soundonsound.com/techniques ... snare-drum

https://www.soundonsound.com/techniques ... -synthesis

[UrbanCyborg]

Interesting articles, Colin. I got interested and banged together a version of the one he says is too complicated. You can get some really interesting sounds out of it, depending on whether you choose VCA responses of linear or exponential, where you set the VCO Octaves, and how you balance things. I find it fairly convincing even with no FX, and I'm sure a little reverb would make it sit up and beg.

Snare Drum 01.voltagepreset

(27.22 KiB) Downloaded 30 times

[martin17]

Oh people, let's assume a little basic knowledge. This isn't about what you might call a snare drum. I'm talking about the very special sound of this snare. I also think it's funny that you always have to build the simplest patches with modules that you have to buy first. It should be possible for all users of Voltage Modular to use or try out a patch. So it makes little sense and no fun to ask a question. If this is the only way to sell modules that you don't actually need, then write that honestly. Attached is the CR-78 snare drum from the Ableton pack "Drum Machines". This is how the patch is supposed to sound...

[utdgrant]

I think that by far the most important part of this sound is getting the nature of the noise component right.

I tried to get that specific frequency response using a combination of stock CA Filters, using different slopes (12dB / 24dB), resonance settings and filter types (low / band / high-pass). After spending quite a bit of time, I still felt that an important element was missing. Perhaps a bit of distortion? Looking at the schematic for the CR78, it does appear to use white noise as its basis, rather than the more complex multi-oscillator-based methods Roland used for cymbals and hi-hats.

This exercise reminded me of why I always stick to samples of analogue beat-boxes!

[martin17]

Thank you udtgrant,
it's probably the specially filtered noise, as you wrote. I also experimented further and then came to this patch:

CR-78 Snare 19.jpg (200.4 KiB) Viewed 561 times

[ColinP]

Oh people, let's assume a little basic knowledge. This isn't about what you might call a snare drum. I'm talking about the very special sound of this snare. I also think it's funny that you always have to build the simplest patches with modules that you have to buy first. It should be possible for all users of Voltage Modular to use or try out a patch. So it makes little sense and no fun to ask a question. If this is the only way to sell modules that you don't actually need, then write that honestly. Attached is the CR-78 snare drum from the Ableton pack "Drum Machines". This is how the patch is supposed to sound...

When I open a thread or post an answer on a forum I do so in the spirit of public discussion rather that thinking it's entirely focused on the desires of one person.

Often people reading the thread will have slightly different perspectives than the OP. I consider Gordon Reid's writing to be valuable rather than "basic knowledge". You might not find the articles I linked interesting or relevant but others might find them useful in understanding some of what is involved in snare synthesis.

Also I think it's a bit cynical to suggest that UrbanCyborg's posting of a preset that uses MRB and M*4 modules as well as his own was is in any way dishonest or designed to sell something. He's simply used the tools at his disposal and been kind enough to share the result of his experimentation.

[utdgrant]

Also I think it's a bit cynical to suggest that UrbanCyborg's posting of a preset that uses MRB and M*4 modules as well as his own was is in any way dishonest or designed to sell something. He's simply used the tools at his disposal and been kind enough to share the result of his experimentation.

And somewhat ironic that I can't try the follow-up patch as I don't own the Vult Spank modules.

[ColinP]

And somewhat ironic that I can't try the follow-up patch as I don't own the Vult Spank modules.

To be fair to Martin17 I think the Vult Spank module is available for free download rather than being part of one of the Vult bundles, but I still think we could do with a little more kindness and generosity of spirit and less suspicion of ulterior motives.

[ColinP]

Looking at the schematic for the CR78, it does appear to use white noise as its basis, rather than the more complex multi-oscillator-based methods Roland used for cymbals and hi-hats.

Yup, I was curious enough to google the schematic and you are right. I've chopped out the relevant bit and posted an image below.

CR78-SnareCircuit.png (326.28 KiB) Viewed 497 times

My analog electronics is so rusty that I can't translate this to code but it looks pretty simple. The part-disconnected transistor at the bottom is being used as a noise diode and then the three transistors top-left form two "modules". I'm guessing the circuit around the top transistor acts as some sort of tuned resonator that rings when pinged by the trigger and the two transistors below appear to be working as a crude envelope generator/gate thingy that amplitude modulates the noise.

But the devil is in the detail.