SSI 2130/2131 VCO ICs

SSI2131 DIY Friendly Triangle Core VCO IC (sheet

Haven’t seen much discussion of these here yet, other than one post in the mail day thread.

They look like great alternatives to the 3340 - 10 octaves of v/oct tracking for only five quid! Does somebody want to whip up a stripboard circuit for the 2131? :slight_smile:

1 Like

The 2130 has extra stuff…5channel mixer on board, sine wave, and fm

But a QFN package… nothing for SMD beginners like me…

I guess they are worth a try, the 3340 being what it is…

You can get the 2130 as a DIP32, designed for breadboarding. They only did a small run for the first batch that pretty much immediately sold out (I was the guy with one in the Mail Day thread) but they are running more, and Thonk is expecting stock next month.

And for the record, they are awesome! It’s nice to be able to design around a triangle core, I might even be able to get a nice ‘West Coast’ complex ocillator out of two of them (when I manage to get my hands on a second)

EDIT: Looks like Amazing Synth has got some more coming this week! Scroll down on the store page linked in the OP and you’ll see the DIP version

1 Like

What does a triangle core do for you?

1 Like

It’s a better shaped triangle, which in turn produces a better sine wave after processing, to my ears at least, which makes for nicer sounding complex FM. Whilst I haven’t tried this in Kosmo or DIY, I can really tell the difference in Eurorack, especially for through zero FM, which is what those SSI chips are made for.

(I should note in Euro I am comparing the sine shaped outputs from TH VCO Maximus modules, after FM’ing a pair of them, with the FM results out of a DPO, which is apples and oranges, but still. I also have the Doepfer thru-zero FM oscillator, which I have modulated from the TH VCO’s as well, and is different again. It’s just a different ‘quality’ to the sound, not better or worse, just different)


yup, got 5 or 6 dab2130’s not yet spoken for :slight_smile:


Hello and welcome!

Would love it you could explain a bit about what it’s like to get these manufactured, both on the design side and the manufacturing side! Seems like a magical process. What tools and processes are involved?

do you mean the IC’s? it’s some very expensive cad software and someone who knows how to use it to start with, then it’s layers of silicone which is “doped” in various places, with different elements, to make a circuit, the elements control which way the electrical charge can flow

bit of explanation here:

the thing with making IC’s is the designers can do all kinds of crazy stuff like make transistors with more legs than normal, and because everything is pretty close together on the die things like tempco are much easier than in a discrete circuit


Hi, there’s an incorrect link
on the page at SSI2131 DIY Friendly Triangle Core VCO IC.

thanks, should be fixed now :slight_smile:

the 2131’s just arrived, will be sending pre-orders out today


The SSI2130 is a very versatile part. Lots of applications in the datasheet :slight_smile:


1 Like

Just noticed that through-hole 2130’s are now available… :drooling_face: Would love a sexy PCB mount for one of those…

yes, SSI made a larger batch this time, so I’ve been able to drop the price :slight_smile: DAB2140 is also now available

1 Like


Do you have a best schematic to build around this? Something with V/Oct and the Through-Zero FM?

1 Like

neils the one to ask about that, but the one in the datasheet, figure 1, seems like a good place to start, then the tzfm bits are a bit further on, have you got the urge to use the vca mixer?

I think this is slightly above my pay grade, I just want to build something that goes bzzzzzzzwwuuuubbbbbttttttt and stays in tune. :slight_smile:

haha, you can always not use them, it’s a smallish number of parts, the pin numbers on the dab are the same as the IC itself

then the tzfm bits plug into pins 21 and 18

1 Like

then you can use a 5v regulator for your +5 and your power supplies negative rail as it is, if it’s -12v for instance.