A4 / AK with x0x Heart


Just finished to solder my xOx Heart pcb to make it work. Not totally finished but I could tune it and use knobs, sequenced by A4.
Modular TB 303 clone that sounds better than A4 in that domain for sure.

After many hours of soldering and wtf moments. Can’t believe it works now.

Cost around 100€ / 115$.

@acidhouseforall :wink:

Edit : first recording

Scenes and midi
Should I trade my A4 for something else? Help me decide

Nice ! So you finally got the right pots.

I had my euro kit at synthcube. This is how I use it these days:



I hope it was simplier than for me!
I didn’t know how to activate SAW / SQR wav > 12V.
Have you got a pdf explaining how to mount that euro kit? I’m curious if your manual was more precise than mine :


I used the wiki: http://wiki.openmusiclabs.com/wiki/EuroAdapter

I can’t say it was easy or fast but I’ve had (and borked) worse kits.


@acidhouseforall or anyone, I have a problem to control CUTOFF and ENV MOD with A4. Almost all the range is covered between 1.8V and 2V, so it is not really usuable and it changes tune at certains values. Any idea?


strange… how did you wire ?


I simply soldered a cable on CUT OFF pin.

I forgot I didn’t trim CUT OFF frequency with trim pot, but I’m not sure if it’s the problem.


Whoa, Sezare56 asked a question… :grin:


I found the answer, thanks to GUEST from openmusiclabs.com on MUFF WIGGLER help, asking about J11 VCF CUTOFF CONTROL IN, I realised I used J3 CUTOFF CONTROL IN instead.
First recording ! FX and Sequenced by Analog Four, Analog Drive as distortion. And an lfo controlling VCF of course !

Thanks again to @acidhouseforall. :wink:
@jingo, don’t you think it is more acid than A4 ?
Anyway, great companion. A 2nd one in the same box is planed ! :sunny:

Companion synth for A4

Yep, and I have to say it has shattered my image of him #sadface :joy:


Surely you mean “MUFF WHINGER”

Or is “MUFF WRANGLER” :rofl:


WIGGLER ! :stuck_out_tongue_winking_eye:


Sad face I had, VCF not working with everything else working, starting new year with a failure…




you sorted this, great :slight_smile:

Now, how about acid not from TB303 clones ? Can you guess what I used here ?


Digitakt, Digitone, Micromonsta ?


Signal path: loquelic iteritas -> mutable instruments ripples -> ryo optodist


@ sezare56 yes, it is more 303-ish, but the A4 is also very good for acid :slight_smile:


HEy Sezare56 !
What’s about the difficulty level for a beginner to this project ?
It’s absolutely my devoted budget and need…


Salut Mat ! I don’t know, I did the basic project, with the PCB only.
Maybe @acidhouseforall can answer better than me for this project Eurorack project.

Do you know how to solder?