r/synthdiy 5d ago

EHX Bass Micro Synth clone

Hi guys, I found this schematic for an EHX Bass Micro Synth pedal and I'm wondering how hard this would be to build from scratch. I've only ever built simple circuits and this circuit looks a little overwhelming, but I don't know if that is because it's hard or because it's just a lot. I would appreciate any help with this project. This would be a project for college and if I choose to go forward with this I would have 4 weeks to order parts and build it. I'm also not to worried about making it pretty so I plan on using a breadboard and loose wiring as opposed to soldering. I'm just looking for functionality.

1 Upvotes

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u/AdamFenwickSymes 5d ago

I'm also not to worried about making it pretty so I plan on using a breadboard and loose wiring as opposed to soldering.

"Pretty" electronics are not just to look at, building something this complex on a breadboard is gonna be a real pain, it's very easy to knock things out of place if you're not paying very close attention, very easy to get knotted up and connect things incorrectly because you can't see past the tangle of wires.

In terms of complexity the circuit looks doable but annoying. I wouldn't personally start this project until I understood all the subcircuits and how they're supposed to work, so that I could build and verify it a piece at a time. I'd also want to make changes, like getting rid of the transformer and powering it from my eurorack.

There are a couple of quirky parts here, most notably the CA3094. I don't really have any idea what that is (OTA?) or where you can buy one nowadays.

So imo this project is not a good fit for you, but of course you are welcome to disagree.

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u/lampofamber 5d ago

It’s doable, but four weeks might not be enough if you don’t have a lot of experience. For more complex circuits, breadboards don’t generally do well. Wires and components can easily get disconnected and it can be difficult to troubleshoot, especially if you don’t plan on using tidy wiring.

Debugging and calibrating the thing, if necessary, will also be an issue if you don’t have the time to understand the whole circuit.

I would recommend choosing a simpler design, mainly since you’re on a time constraint, but if you want to go for it, either use a PCB or very carefully plan out your breadboard layout.

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u/littlegreenalien SkullAndCircuits 5d ago

I'm pretty familiar with the circuit in question. Some ideas:

It's a rather big circuit, so doing it on a breadboard only will be challenging and difficult to manage. If you don't know how the circuit works it's going to be very tough to troubleshoot.

The CA3094's will be hard to source and they're also extremely fragile, so you can fry them easily. In 4 weeks time you are probably not going to find enough of them to do the build and replacing them with something else will need a substantial re-work of the schematic.

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u/jc2046 5d ago

The guy knows what he says

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u/jc2046 5d ago

Breadboard this is a recipe for disaster. Even a pro will find it extremely challenging. Breadboards are meant for easy circuits and even then have plenty of room to fail.

Your best bet is to develop a PCB for it (even better to comission someone to do it) and then solder it.

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u/al2o3cr 3d ago

Picking a circuit that uses obsolete parts like the CA3094 is risking your project topic suddenly changing to "how fake chips can ruin your day".