Patch.Init for guitar effects

I’ve been programming some simple guitar effects VSTs and I want to move into the embedded world.

Can I use the Patch.Init with the Submodule to experiment with DSP? I don’t need a proper enclosure with switches, I only need a hardware platform to test my C++ code. Obviously, I need 1/4" in and out jacks and some knobs I can assign to different parameters.

I don’t know if this is possible with Patch.Init… I don’t think I have yet a full picture in my head of what is required in terms of hardware.

I’m sure you could use Patch/submodule although you might have to adapt the input for guitar.

You might want to check out ‘Terrarium’ - it a minimalist Do It Yourself Guitar Pedal based on a Daisy Seed - just the Printed Circuit Board:

Electro-Smith has them in their store also.

You would need to boost the very weak guitar signal to +/- 5v and then attenuate it back down to line level again (+/- 3v) on the patchSM, so it really would not be ideal for your use case.
If you were to include the patch.init in a small eurorack system with a instrument input module (e.g doepfer A-119) and a line out module (e.g ALM hpo) then patch.init would make sense.

The patch.init/ daisySM would also require a +12v and -12v power supply, which as far as I know is only really achievable with a eurorack power supply, or a bench power supply. So you would basically have to start a small eurorack system to be able to use patch.init as a hardware test platform for experimenting with c++.

Once you add the extra costs of input module, output module, case and power supply, the daisy petal ends up being a fair bit cheaper than patch.init, is designed for guitar levels, and will have a bunch of examples to help you get started that are guaranteed to work with the exact hardware of the petal.

I would absolutely love to get the Daisy petal but it’s out of stock. Electrosmith is located about 20 minutes from me and I like supporting a good local business… when they have what I need.

I read about the Terrarium here and it would be a great solution, but I really don’t feel like going on an online hunt for all the components. I’ve built analog stuff before but that was when you could run to a nearby RadioShack and find almost everything you needed. Just recently it took me about four weeks and a return to finally source online a simple switch for a guitar amp attenuator.

I like fooling around with the synths in Reason and I kinda like the idea of getting deeper into it with an eurorack system. I started reading up on it and it’s a deep rabbit hole. On one hand it would be a lot of fun, otoh it would take me away from the guitar related DSP I want to write.

If I did want to go the eurorack route, would I need anything else besides what was mentioned (A-119 + patch/daisySM + output + power supply)?

Just some patch cables and a small case. I know you said in your original post you didn’t need a case, but in eurorack the case is pretty necessary since all modules are bare circuit boards behind the front panel. There are lots of cases though that have power supplies built in, like the 4ms pod 64x.

Also worth considering the daisy field, which would handle guitar level signals better, seems to be in stock, and would still most likely end up cheaper and less distracting than starting a eurorack. The buttons and screen could also present a nice range of stuff to experiment with in c++. No footswitches or expression input though like the petal. Really depends on if you can see yourself getting into modular synths though, in which case a patch init and small case would be a nice introduction to that.

Thanks a lot, I appreciate the education. I was thinking… can I test my DSP code not by playing a guitar through a 1/4" jack, but by inputting a .wav file into the daisy pod and listening to the result through headphones?

I don’t need to test by playing live, I can have a recorded .wav of my guitar and use that. Would this work?

That would definitley work on a pod yea :slight_smile: you could probably play guitar into it too with a 1/4 to 1/8 in adapter and a little digital gain.

Cool, that’s what I’ll do! Meanwhile I’ll also keep an eye on the petal availability. I’d like to have it eventually.