2370 Spring Spring Crunchy Spring Spring


AHHHHHHHH Hot dang!!


No info yet though :frowning_face: I have a Kosmo konversion of the Music Thing spring reverb close to ready to go but not yet, so it’ll be a race to the wire to see which way I go…


at last! been eagerly waiting for this


Does yours have feedback? Looks like this has no feedback control either. Still, added to cart…


The Music Thing design has feedback.

Brave! I want to see more information first.


I am buying 2 at least big synth room fo them

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I have one on order. Wish I had a bit more info so I could pick out a spring tank.

Sounds like i get a spring reverb controller with zero design work either way.

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Project page says it works with any tank. Sounds like a challenge.


Ordered even though I have a backlog of builds… Finishing the VCADSR off over the next two days, then onto the quad LFO…


Oh, this is timely! My friend left me an old spring reverb the other day and it only took a week to clean out the decaying sticky backed foam from around the springs. What is up with this old adhesive? It should be dried and cracking by now but no, it just gets stickier with every swipe of the cotton swab. It’s so nasty!

After measuring the inductance, I designed a circuit to drive it with the right response but I have not built it yet. This one sounds promising.


its arrived, good job I have a backlog , looks nice and simple though once BOM comes in… Hope we get a build vid as I like them


Well, I just got the panel&pcb in mail. Lets see what components I need, at least two LM13700:s and…


Hmm, it puts the input into a comparator so you’re always sending a ±10.5 V pulse wave to the tank. Not clear to me I’d want to do that… anyway it’s certainly different.

Still in stock at Tayda! Out of stock at Thonk and seemingly gone (DIP version I mean) from Mouser and Digi-Key though.

BOM describes J4–J9 as EURORACK POWER CONNECTOR, obviously they’re not…


Looks like I have all of the parts except those plugs and a spring tank.

Anyone have a US source for those plugs. Only ones I have found that may work are these:

And I guess I will play some spring tank lottery and see how it goes.

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Fortunately I have several tanks in the shop at the moment

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I got mine up and running.

I did spot one mistake on the board. The LED symbols have the flat side to positive. There is a + symbol with the flat side of the LED symbol, so it is a bit confusing. Follow the + symbol, not the LED symbol.

I can confirm that the RCA sockets I linked above do work. Here is the spring tank I am using, if anyone is curious.

I will share some sample audio once I have it uploaded somewhere.


Looking at the BOM, it’s a good job I orderd 100 100K’s for the 60 needed on the Quad LFO… Another bunch to get used right out the bag :wink:

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Yeah, I order 100k in quantities of 200 these days.

Looks like about 9 of those, and 4 transistors and 4 1k, are used only for the LEDs:


The parts count could drop considerably if you taped over the LED holes…

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