IR3109 PCB Petition

This is my signature in favor of Olivier bringing this filter board back to the Mutable store. Others in favor, post below!

you could always have your own made using the eagle files here:

@herrprof that’s always an option, but bringing it back to the MI store means we are supporting Olivier. :slight_smile:

Well, I doubt he would mind you having it made somewhere else, and then donating a couple of bucks to him (might even be better)… :wink:

I have realized that selling designs which use vintage ICs is totally incompatible with my values and beliefs, and some of the things I am trying to say with mutable instruments such as:

  • You too can learn how to build your instruments and understand how they work, without proprietary “blackboxes” getting in the way
  • “Vintage” is overrated
  • Lean designs sound great

I have said it many times: the IR3109 is just 4 OTAs, 4 buffers and an exponential converter on a chip. None of these parts have any “magic” in them and do them in a way that deviates from the laws of physics. Proof: LM13700s have been successfully used to create indistinguishable Juno VCF/VCA chips replacements. The only difference between the IR3109 board and the SMR4 mkII are the signal levels and capacitor types. Why don’t you buy a SMR4mkII and try to build it with the same signal levels as the Roland filter? Maybe breadboard a variant which uses FET buffers or the 13700 Darlington buffers if you think it might impact sound? Why don’t you try adding non-linearities (Back to back zeners) in the first integrator to try to get a different sound? Wouldn’t you be much more satisfy if you did a bit of research and managed to get that sound back using the standard parts instead of the dead chip?

1 Like

xtrmnt, v’cent: what kind of support is it to tell a designer “your stuff is neat but we’d rather have the one with the Roland logo instead, the one you’ll never be able to sell at a large scale”?

The degree of support is somehow quite low given the fact you have to order, stock, handle, bill and ship these PCBs in these gigantic Amounts I suppose its about 2 hrs of work and loads of Money (i think reordering saves the Setup Fee so it cuts down the costs by 70€ right down to about 45€ for a one off) till the first PCB of this one piece run can be shipped. For my taste a bit to much for a PCB expected to cost something similar to the others (say about 15€). So just grab the Files from GitHub and do the PCBs on your own - if I can manage to get a PCB made you can do as well. schrab would even do them in his Kitchen sink. Thats why its called DIY :wink:
Oh, and Olivier is right - you are probably better of playing a bit around with the SMR-4 than chasing after a dead chip thats only famous because it was built into an Iconic Synth, otherwise rather average. Its only “good” because your listening habits got used to it and you “learned” the Sound.

Lets make Buttons or Stickers with “Vintage is overrated”, go to the Frankfurt Music Fair and give them away as a Gift :wink:

@ fcd72 … i’ll be at your studio this afternoon picking up some overrated old equipment ok?

You wil find none - its all actual Stuff in the meaning that nothing better has been produced till now :wink: Oh wait, i have a Vintage SixTrak…hardly ever used…

pichenettes : Well, you have already made the board, and when you stopped offering them you did release the board designs (awesome awesome awesome!) , so why not tell you
"Thank you dear pichenettes for making this, i really appreciate it" by sending you some random amount of money for a cup of coffee or something?
It’s not like people will stop buying ‘your’ designs because you stop offering the old ones, and i’m certain fcd72 is right in saying that people only want the old ones because they were used in a iconic synth, not because they are truly better than your designs :slight_smile:

At least thats why I have the Roland, CEM and SSM board: just because the Filter were used in the JP8, VS/ESQ-1 and PPG. I’m the greedy Collector :wink: I hardly ever use them, most times i use the SMR-4 or the 4PM. But i have to admit with the SSM2044 Filter the Shruthi gets closer to the PPG Wave (2.2+) than the Waldorf Plugin or the MW2. Shruhi sounds totally unVSy with the CEM (at least when i try) but competes well with the ESQ… To me this “get a famous Filter no matter whatever Oscillator signal i stuff in” something like “i stuff a BMW engine in my Kia to make it more racy”. It never gets similar to the original.

Of course it doesn’t get similiar to the original, i mean, the BMW has racing stripes for starters ! :wink:

Nahh, i guess people are mostly looking for that “magic sound from machine X” that they once heard someone used (prophet, PPG, minimøøg etc), and hope that it will somehow inspire them to achieve that level of perceived quality… Meh…

Most of the sounds from “back then” weren’t achieved using a specific Synth but with massive Outboard Gear and polished Production. If you listen carefully to some productions you can hear running separate Tracks thru different Reverbs, and loads of independent Delays for every single track, using Subharmonic Synthesizers on Base, Tricks like the Edison’s Stereo Bandwith Manipulations all this carefully recorded in real Tape. Sometimes i imagine outboard gear used on ZTT Productions stuffed in just 2 Racks higher than the WTC. I hear nothing of this nowadays instead loads and loads of compression (digital ones…) and twangy Reverbs. The Art of Production is vanishing - I’m the only one keeping it up with 3 different Outboard Reverbs :wink:

I’m more interested in what other filter types wich are not yet available (yet) for the Shruthi-1 would be an addition to the the already huge arsenal.
I bet Olivier has some ideas about this.

I think we reached a bit the end of Filter Design with the 4PM. The only thing not tried yet are the Mœœg Ladder Filter and a Steiner Parker Type of thing. Both of them wouldn’t expand the sonic possibilities of the Shruthi beyond the 4PM, so personally id only get them to complete my collection :wink:

Yups, and the upcoming MS-20 VCF. Maybe and VCS/Arp diode filter, but I doubt that would offer much beyond the Steiner-Parker type of filter. Another thing would be a variable slope filter (Serge etc), but I don’t see one of those being feasible considering the PCB size constraint.

How about the SEM filter?

Just switch your 4PM to lp2 or lp3 and use only boring Waveforms :wink:

@shiftr: The SEM filter is called a SVF and you can get two of them on a single board. Bargain, bargain!

>but bringing it back to the MI store means we are supporting Olivier

Supporting Olivier is best done by helping him break even on the new work he has done. Not resurrecting old stuff.