Using VCO module and VCA alone to replace A4 DCO



I’m gonna guess the A4 is B.


The moogerfooger freqbox-107, although now discontinued, would make a great extra oscillator. It is self contained with its own power supply. Plays really well with the A4/AK.


Out of curiosity, wrt this thread and the ‘dull’ thread, what is it that made you select B ?

Just a few words :wink: , i’ll leave this up for a while longer and then spell out what was behind A, B & C


I was pretty vocal in the other thread on how I feel about the A4, and I surly don’t claim to be able to hear the difference between raw oscillators, but I don’t believe that I can get the A4 to do that basic flabby old school wop that comes so easy on something like a slim phatty. It can do something like that, but it’s not really the same. I think it’s a combination of things, not just the VCO element alone.
Fun challenge though, looking forward to seeing what others say, and of course, the results.

I chose the Take B, because I have been making sounds with my A4 a lot, and it just seemed like a good guess.
The audio clip is a bit deceiving with the volume difference.
Take B just had this whispery noise, and a hint of soft roundness that made me think it might be the A4.

Again though, for me it’s not simply the DCO vs VCO.


I couldn’t agree more, the Oscillators are just one part of the picture, the filters are probably the magic sauce imho

Full disclosure, whilst there are VCO(s?) used in the comparison, it may not be a great test, maybe a Moog Osc would jump out (in the way a Moog filter almost certainly would)

I think if anyone else has a listen and a view it’d be interesting to rank them In terms of least dull & least thin or most pleasing to the top


Wild guess here, but am thinking all -3- come from the A4/AK, but the hardest one for me was C as it sounds a bit like my Waldorf Pulse+, but what do I really know. I tried. I just know that the AK/A4 has a vast sonic pallet and would not surprise me one bit if A,B,&C were all the A4/AK.


As per the thread above, everything is fed through the A4, but the source Oscillators were varied (no other variation after the osc shape is setup between the 3 patches) … A4 is in there along with some ‘real’ VCO action :okej:


Bump … see this … before the big reveal, surely more than two peeps vaguely curious about this :loopy:


Tell us! The suspense is killing me.


Dont know what is what but B is def. the least attractive.


Well, here’s the deal then …

There’s been a lot of finger pointing at B, that’s actually the only True VCO, it’s not a prince of VCOs by any means as it’s the Doepfer one baked into the original Dark Energy and that whole synth voice sounds very very fine to my ears

A was the Saw from the A4

C was the Tri from the A4 with PW@32 (a nicer fuller saw style sound imho)

I guess the point was that the ‘dull’ oscillator theory banded about a bit on the other thread has some room for interpretation … to my ears, when I was A-B-ing with this little test setup, all the magic became obvious when the DE filter was introduced, it was just more satisfying in some regards even though the VCO sounded a bit less clear than the A4 ones … where it shows is that the mid range saw shapes are much of a muchness, but when you drop down, the a4 shape tickles the highs more and you don’t get the roundness/fullness you do with the ‘duller’ VCO on the DE or even the Tri (mod) osc shape of the A4

I guess the point I wanted to get across was that there is scope for a nicer saw (imho) and that the osc wasn’t really the only big player in the overall sound stakes in terms of raw appeal

I’m not disagreeing with the perception that the sound is sweet spot dependent, it’s just too flexible to sound ‘right’ in all the ways it is malleable … when I fire up a MS20mini and adjust that, I struggle to get something that does not sound glorious … a factor of the core design and the seeming simplicity

The A4 filters can also be used to create big basic sounds if you tweak wisely, it’s just a bit more prone to going beyond the sweet spot and thus the frustrations … but wrt the above thread, there may be less to derive from opting for an average vco of a similar type

I was kinda hoping people would rate them as C > A > B to promote a bit more thought about what the A4 can deliver, but there’s no doubt that the DE VCO has a better low end saw than the A4 saw although the A4 saw (A) may seem more pleasing than (B) … I certainly prefer the adapted Tri because it offers more interesting ‘pulsewidth’ destinations for the same core osc shape, the transistor pulse is also a great shape


Just wanted to chime in here, and add that another awesome option for the A4 is circuit-bent hardware.
Because it’s CV channels are so flexible, they can be used to control lots of stuff that you wouldn’t think would sound so good.

Case in point, the monotron delay by Korg. I found that it’s oscillator tracks over several octaves, and it’s LFO tracks over two or so. This gives you a 2-voice, paraphonic semi-modular with an ms-20 filter. The filter is also cv-able, and it’s resonance can be played if you mod it to add a resonance control.

Here’s mine.
If I remember correctly, this patch has the lfo and oscillator receiving the same note commands (or maybe offset by a fifth), then the lfo is applied to pitch. The monotron’s oscillator is modulating it’s filter cutoff, and just on that very last note I add in a bit of the monotron’s delay, which because it runs through the filter which is being modulated at audio rate(the oscillator’s), adds a metallic twang. That all joins an a4 oscillator, and the filtering is done by the a4.

Thanks for inspiring me to use this sort of setup more!


I knew I’d pick the VCO.
Again, fun challenge, and really does open perspective.

Due to the “other” thread, I’ve been really inspired to try and coax stuff out of the A4 that dont come so easy to it.
I start to like the A4 even more, but it also becomes glaring that the A4 is just no going to scratch that itch.
I do like the sweet spot theory, but there’s something special about a synth thats just…glorious, even if it’s “basic”
I think people get hung up on what “dull” or other adjectives mean subjectively, VCO’s vs DCO’s blah blah and overlook the bigger picture, which is the A4 is not really designed to clone sounds from particular 70’s 80’s synths therefore it cant really do that.


Once I return from travels, I plan to focus heavily on some big bass patches that make heavy use of unison, peaking filter (for bass boost) and LFO/ENV for subtle PWM of the saw waveform.


I’m using a Sound Technology E340 Cloud Generator into my A4Keys, the 8-Saw sounds really good going through all those lovely filters on the AKeys. Beautifull sound with detuning for massive classic Arp Basses etc.

The pitch part and the note parts are played in separately which limits things a little, but it’s worth it for the sound results. A bit closer to the classic Roland sound which I love. Lots of Oscs!!
The AKeys is no slouch in that department either!


I also added the Dark Energy 2 and Aturia Minibrute to my A4 and now adding a Doepfer A-110-4 for some FM and the A-102-9 Filter. Looking forward to check how it sounds with the A4.

I already tested the Audio Ins of the A4 and for me, Dark Energy sounded better when recording into my Motu828 then using A4 Audio In and recording via Overbridge. I can upload the files if anyone wants to have a listen.


I would call the MI Clouds a “out of space” fx unit!


I’m a noob on this subject and my A4 is still on the way in the mail. How would it be to use my Blofeld OSC’s with the A4? Do the OSC’ have to be modular/eurorack?


If you want to sequence the incoming audio then you have to use CV, there is no midi sequencing, you could play the same way with the keyboard, it will send pitch out to start and pitch the waldorf, but it is only for live playing of the keys … midi is not sent out from the sequencer

you can drone your blofeld for sure, but in terms of regular sequencing it’s simpler with a CV capable synth