Korg Minilogue

[IncarnateX]

Listening to all the minilogue demos, it doesn't sound like an arp.

There must be more to the sound of an arp than just the filter or what?

[ghettosynth]

Yeah I noticed that too. A blast from the past. Wonder what its used for? In the old days I would make very low parts count voltage controlled LFO's out of (as best I recall) just a 3900 and little else. Pairing two or more of em, cross-modulated for chaotic LFO. Thats about all I recall using a 3900 for. Think it could also be faked into behaving like a VCA. A unique opamp. Single-ended power supply and sorta noisy though. Maybe some of the noise because it was typically used with such big-value resistors.

Doh! I don't why this didn't occur to me. I would bet money that it is the filter and that the filter is/is based on the Arp 4072 filter. This would make a lot of sense in terms of the progression of product design.

Maybe it is partially based on it (4072 is almost the same as 4075), but in this interview (in Japanese) (translation here), the designer said it sounds completely different from the filter it's partially based on (Odyssey rev. 3 ARP 4075). At least it's obviously true when comparing various recordings.

Yeah, well, I could be completely wrong, it's just a guess based on the fact that they have existing designs and they have been reusing elements of their old designs. It's just that it's such an odd duck of a chip to stick in a new design, so, if it's not in the filter, then it seems a bit out of place.

We were able to figure quite a bit out about the Prophet-08 from just looking at the boards, of course, that's much easier because it was a synth on a chip. Still, I would think that with some good close up images, we could get some sense about what's doing what.

Ok, I just read the link, it is the filter, it is based on the Arp 4075, but the assertion is that it's a completely new design. I'm not buying that "completely new" part so much, it sounds more arpish to me than it does moogish, if we can paint with broad strokes.

My bet is that the core is very very similar and they've changed the feedback paths for flexibility, and because they have to modify that somewhat to obtain voltage control.

[AnX]

Are they using tech from the odessy reissue perhaps? Or is that a diff kettle of fish?

[ghettosynth]

Are they using tech from the odessy reissue perhaps? Or is that a diff kettle of fish?

Yes, that's what I'm suggesting. At the very least, I think that they're reusing their experience with the design and that's why there's an LM3900 in the filter. I think that if you were to actually start from scratch you wouldn't say "I think I'm going to build a filter based on the LM3900."

[werp]

[Shy]

Are they using tech from the odessy reissue perhaps? Or is that a diff kettle of fish?

Yes, that's what I'm suggesting. At the very least, I think that they're reusing their experience with the design and that's why there's an LM3900 in the filter. I think that if you were to actually start from scratch you wouldn't say "I think I'm going to build a filter based on the LM3900."

I think LM3900, being a very widely available and very cheap option, is probably a very good option for a compact, mass-produced filter, so I'm surprised that more companies haven't been using it. The ARP dynamic filter patent from the 70s probably expired long ago.

[ghettosynth]

Are they using tech from the odessy reissue perhaps? Or is that a diff kettle of fish?

Yes, that's what I'm suggesting. At the very least, I think that they're reusing their experience with the design and that's why there's an LM3900 in the filter. I think that if you were to actually start from scratch you wouldn't say "I think I'm going to build a filter based on the LM3900."

I think LM3900, being a very widely available and very cheap option, is probably a very good option for a compact, mass-produced filter, so I'm surprised that more companies haven't been using it. The ARP dynamic filter patent from the 70s probably expired long ago.

Cheap might have something to do with it, sure. I'm still betting money on experience with the Arp design leading to a natural evolution. I'm not sure how much cheaper it would be than say an LM13700 considering that you have a matched pair on each cell with the LM3900. LM13700s are about fifty cents in quantity, LM3900s are about fifteen, give or take. My bet is that four pairs of matched transistors would make that a wash, if not give the advantage to the LM13700.

I bet they started with the Arp design, said, how do we make this 12/24 with CV controllable resonance, and went from there.

[Daags]

Yeah, well, I could be completely wrong, it's just a guess based on the fact that they have existing designs and they have been reusing elements of their old designs.

you're wrong. at least in terms of reusing elements of their old designs.
Tatsuya himself stated quite bluntly and plainly in NAMM interviews that this is a brand new design, from the ground up. They started by assessing what components of a decent quality were inexpensive and easily available to them, and then created their entirely new design from that starting point.

Unless he was lying, or fudging the facts for a layman audience.

you'll have to actually read the thread to find that interview if you are interested in hearing it for yourself. or search for it independently. soz.

[IncarnateX]

Anyone from Europe whose synth has arrived yet? I have mailed Thomann in Germany but they are silent as the grave

[ghettosynth]

Yeah, well, I could be completely wrong, it's just a guess based on the fact that they have existing designs and they have been reusing elements of their old designs.

you're wrong. at least in terms of reusing elements of their old designs.
Tatsuya himself stated quite bluntly and plainly in NAMM interviews that this is a brand new design, from the ground up. They started by assessing what components of a decent quality were inexpensive and easily available to them, and then created their entirely new design from that starting point.

Unless he was lying, or fudging the facts for a layman audience.

you'll have to actually read the thread to find that interview if you are interested in hearing it for yourself. or search for it independently. soz.

I've already addressed this. I did read the translation, and I still may be wrong, but I think that they started from the arp design and kept/adapted the core. He says, point blank, in the same interview, that it's based on the Arp 4075, so, in a basic sense, I have already been proved right. We'll see how far it diverges from that. From a layman's point of view, the adaptation could be considered a new design, from mine, not so much. I wouldn't call anything based on an existing filter a "completely new design."

I have a design of the Arp VCO that uses very few parts. It doesn't use the same chip, it doesn't use the same expo, it buffers some signals differently, it's a bit more minimal. Someone else might say that's a completely new design, I would say that it is an adaptation.

So, based on what I've read, it's pretty certain that the LM3900 is the core of the filter in the same basic way that it is in the 4075. The question is how much further did they go with the "design?"

But, without, at minimum, pictures of the board, we can't really develop the guess further.

In any case, you cannot use the arp filter directly in a modern polysynth. There is no voltage control of resonance in that design so you would have to add that. It's not a 12dB/Oct filter either, so you would have to adapt the design to accommodate that.

[D-Fusion]

Anyone from Europe whose synth has arrived yet? I have mailed Thomann in Germany but they are silent as the grave

I guess it is becaue they don't know when they arrives
I hve the same problem here with my local shop where they got their demo synth but not mine yet and i am no.1 on the list here.

This is in Norway

[Daags]

I've already addressed this. I did read the translation

read the translation ?

no. the interview to which I am referring is not in text, which is why I said 'hear it for yourself', it is also in english - so no translator was required. check the thread, it was clearly labelled so you won't just have to click on every a/v link looking for it. will his words be any different to the translation ? I don't know. I don't need to, either.

in terms of semantics, whether minilogue qualifies as a 'new design' in your books or not ... I think I'll defer to the expertise of Tatsuya - the guy designing a range of mass produced analogue synths selling by the truckload, some of which are destined to be future classics if not classic already, over some anonymous dude on a forum

once again - in terms of pedantics, sorry, I mean semantics you can of course find merit in sharing your contrary POV despite Tatsuya's claims... at least the laymen amongst us will learn something (possibly) from this process. chip names, and that kind of thing.

[IncarnateX]

Anyone from Europe whose synth has arrived yet? I have mailed Thomann in Germany but they are silent as the grave

I guess it is becaue they don't know when they arrives
I hve the same problem here with my local shop where they got their demo synth but not mine yet and i am no.1 on the list here.

This is in Norway

I'm in Denmark so I guess we are in the same boat. Would be polite if they would answer that they don't know. Well, politeness is not my strongest trait either, so I guess patience is the key word here.

[ghettosynth]

I've already addressed this. I did read the translation

read the translation ?

It was linked.

[IncarnateX]

check the thread, it was clearly labelled so you won't just have to click on every a/v link looking for it.

Isn't it the one you posted yourself you are referring to, Daags? Here I bookmarked it:

https://www.youtube.com/watch?v=E1N8f3fVWSk[/quote]