Dual svf versus 4p

I know this has been discussed and I’ve done some searching to get feedback but I’m trying to make an important decision. Buying everything is not an option. Hell, buying this shouldn’t be, however. I have a couple v2164d chips now and was planning on building the dual svf. Also I have a Red Alert case currently housing my SMR4 mkii (1st Shruthi) and I think a Polivoks would go nicely in that, and make more sense. The SMR4 mkii will likely become a permanent resident in a Roland keyboard with programmer style controls in the top deck.

So, if I’m going to build two more Shruthis (I have an SSM2044 board but it just doesn’t want to work) to go along with my sidekick (and possibly the NovaDrone) should it be a 4P or the dual svf? Thoughts on sound and how to get the widest range here would be nicest. I’ll probably be poly shruthi-ing these sometimes.

i can’t say anything about the 4PM, i’ll build mine this week. but about the SVF, it’s one of the filters i’m quite sure i won’t let go. you can get some special modulations out of it which the others can’t, because it has 2 separate filters that can be set totally different. so sound wise it’s unique.

This is quite a tough question.

The 4PM is insanely versatile but relatively classic in its approach. It’s still “one” filter, with one single cutoff frequency control and one single resonance control. The number of filter options and the 4 feedback settings make it (in my opinion) the swiss army knife filter. Still, due to the fact that it’s only some filter settings and one cutoff and one frequency, it’s very simple and natural to use. If I want to process external audio but I don’t really know in which way I should do that, or if I just want to let things happen with no prior knowledge of what I want to achieve soundwise, I’m going to hook up the 4PM to my sound card, because I’ve got every single option available for tweaking in a still very simplistic manner.

The Dual SVF is quite different in its approach. Because of the 2 cutoff and resonance setting, and because you have to use the mod matrix to really take benefit of this filter, it implies more tweaking, and thus in my opinion it implies more prior knowledge of what you want to achieve. It’s also very, very versatile of course, and of course you can tweak the parameters randomly and come up with crazy sounds. But when using it I really feel like it’s more an instrument on its own, that you need to spend a lot of time with to master it correctly (I didn’t take the time to do so yet, unfortunately). It’s really got a lot of horsepower, you can get all the nasty sounds you never ever dreamt of, or very smooth tones. For instance, if I remember well, setting up the filters as LP in series 1 octave apart and adding some resonance to both will make your shruthi sound organ-like, whatever osc you pick. Set the sub to -1 octave, the 2nd osc to +1 oct, the filters to +2 and +3 oct and you get a crazy mother-of-octaves organ sound. What filter allows you to do so? Compared to the 4PM it’s really a filter for the tweakers and the deep mod matrix lovers.

Both sound pretty “hifi”, the exact contrary of the polivoks filter. I don’t think I would say “one is better than the other”… Both are perfect for the tweakers, you can achieve silly sounds with both, they can be used perfectly well as standalone filters, and you don’t have to spend 3 hours to get one or the other to sound right if you know what you want (and if you don’t know what you want, one day is not enough to try every combination…).
Some may disagree with me, but I’ll try to summarize. I think that the 4PM is more “generally” useful in a studio setup, where you also use the shruthis as signal processing units. Setting up the 4PM is pretty quick, and despite the number of options I feel like it’s a time saver. The Dual SVF is really worth if you can afford spending some time with the synth and try a lot of things. In that case, you can really create weird and very original sounds.

I’ve got both-Dual SVF is a brighter, more distinctive filter in my opinion and is fantastic for drones and pseudo-modular synth effects. You can also set the two filters to lock together, in which case you have a single filter with dynamically adjustable peak separation (a la OSCar) and plenty of different behaviours (by choosing serial/parallel and combinations of responses).

I totally agree with MicMicMan’s post.

Thanks for the response. Wow MicMicMan, great description. I already have the BOM ready for the SVF and that might have taken me over the edge. It kind of makes me think I should go with the 4P and the SVF and maybe save the Poli for later…

I also have both and I agree with what has been said about them so far. I’d also add that the 4PM has more punch for classic bass and lead sounds and the Dual-SVF can do some nice nasal sounding things. Also it would make little sense to put a Dual SVF in a programmer since you’ll spend more time in the matrix, while something like the 4PM works very well in the programmer imho!

@ pichenettes

are there future-planes for a dual-svf-kit? that would be awesome … otherwise i have to buy a smr4-kit and order the parts (PCP, V2164D´s and some other stuff) separately … that would be no problem at all, but a kit … let´s say a special edition with a very special case would make things easier

Only the SMR4 mkII will only be sold as a full kit. Doing a semi-kit with the dual SVF? Maybe, but not before some time.

@Noisbuddy
The Digital Board and flashed ATMega are also available on the store, so if you order parts anyway…

@MicMicMan
You made the SVF sound wonderful! It’s been moved into my ‘must buy’ list.

it is. like has been said a couple times here, it’s a mod matrix machine.