Repro-1 (out now)

[Urs]

The non-linear function isn't that big of a deal. The bigger deal is solving the linear system imposed by the Jacobian matrix (green area in the PDF)

Ok, so single cycle (and even better, simd) mul and div would make greater impact on overall performance? And if I replace tanh with quite close thing with 2 muls and two adds, but get 8th order system of equations, I might get worse performance than with tanh? (I ask this because I'm pondering should I spend time on investigating particular trick).

There's loads of approximations to tanh which involve just a few multipes, adds and a division. This is usually not as much overhead as the process of solving a Jacobian.

BTW, for 4, why did you choose average of two "iterations"/estimates, instead of just taking value of second one? (btw, on first glance, this approach looks to me like fixed point iteration, don't know if it actually is equivalent)

Check out Heun's method. One can do either, but this one was particularly well behaved.

BTW2, have you tried multiple correction steps with 4, for example 4 steps than average? I would be interested in comparison of 32x oversampling vs 4x oversampling + 4 correction steps (should have same processing loads)

As soon as you need more than 2 iterations you'll be slower than Newton's method for 90% of the factory presets... hence I wouldn't even begin to try this

[moscom_electronics]

To your ears, which filter behaves most analogue

Ears are typically used to receive sound. Actually, that's is the only thing they can do. Hehe.

How does a filter exhibit it's behavior is not by sound? Digital filter can't be measured for power consumption, temperature or other physical attributes, and we don't have access to the internal bitstreams- which leaves us with the obvious conclusion that behaviour == sound in this poll.

Or, as many have pointed out, if you want to put sound and behavior in the same boat, how does the filter responds at extreme settings... Sorry to bring this back again, but it is really what it is all about, artifacts. And this is easy to quantify with your ears. In this respect 3, 1 and 4 were almost identical except that 3 had much less artifacts when pushed hard while still bringin somethig to the sound (in contrast to 2 and 5).... And then, because you do not expect artifacts from an analogue filter (or at least not digital artifacts), then this goes back to "which one is the most analogue".

[deltaMACHINE]

Filter 4 Sounds the BEST!
All the 100 % digital perfect stuff is not that what aim looking for.
I like artifacts and distortion and what ever you say Urs its a matter of taste

[EvilDragon]

The point is that this is supposed to be an emulation of Pro-One, and Pro-One doesn't have those artifacts. Hence, it is not a matter of taste, it is matter of precision in emulating and getting it to behave as close as possible to the original. You're missing the point.

[AnX]

I wonder how many of the 314 voters have a pro one....

[beely]

I wonder how many of the 314 voters have a pro one....

It doesn't matter. The question was not "which filter type is closest to the Pro One" (even if there was such a thing as a "golden" unit that adheres best to the spec), it was "which sounds analog to you", whatever you take that to mean.

Obvious digital artifacts do not sound "analog". Subtle ones *might* to one person, but definitely not to someone else. And some artifacts might actually be the same as the (desirable) analog behaviour.

[AnX]

I wonder how many of the 314 voters have a pro one....

It doesn't matter. The question was not "which filter type is closest to the Pro One" (even if there was such a thing as a "golden" unit that adheres best to the spec), it was "which sounds analog to you", whatever you take that to mean.

Obvious digital artifacts do not sound "analog". Subtle ones *might* to one person, but definitely not to someone else. And some artifacts might actually be the same as the (desirable) analog behaviour.

Its matters in the sense that diff synths behave very differently. The question was not 'sounds' it was 'behaves'....

[urosh]

I wonder how many of the 314 voters have a pro one....

After quick search, two users that posted in this thread (there may be more) either use or have used pro one. First one commented that "filter one comes closest to the pro-one i borrowed and was a guest in my studio for a couple of months I like sound of filter 4 aswell" and second that "filter 5 is a nice filter, that's my guess for the most accurate model. 5 sounds more consistent over it's range to me, not sure if it reminds me of my old pro one or just a anolog but vaguely familiar compared to the other filters". Go figure.

[core]

I wonder how many of the 314 voters have a pro one....

After quick search, two users that posted in this thread (there may be more) either use or have used pro one. First one commented that "filter one comes closest to the pro-one i borrowed and was a guest in my studio for a couple of months I like sound of filter 4 aswell" and second that "filter 5 is a nice filter, that's my guess for the most accurate model. 5 sounds more consistent over it's range to me, not sure if it reminds me of my old pro one or just a anolog but vaguely familiar compared to the other filters". Go figure.

So one Pro-One doesn't sound exactly like the other, and people hear/perceive things in a different way.

[Arrested Developer]

I wonder how many of the 314 voters have a pro one....

I had one, but it's over ten years since then.
However, if you give up the placebo modus (i.e. hear what you want to hear), things are really tough.
From the 5 modes, i had the impression that 2 was a bit weaker than 1,3,4,5 but i wouldn't say that one mode sounded more "analog" than the others.
"Analog" is not a specific sound it's a variable result of the involved parameters.

When i read discussions about VA and analog, my overall impression is that those people who are loudest in pretending to hear differences would probably miserably fail in blind tests and/or prefer cheap digital filters.

[pdxindy]

When i read discussions about VA and analog, my overall impression is that those people who are loudest in pretending to hear differences would probably miserably fail in blind tests and/or prefer cheap digital filters.

I suppose for people who are pretending, that might be true... but then there are the people who are not pretending and can actually hear the differences... that is another story.

[Arrested Developer]

When i read discussions about VA and analog, my overall impression is that those people who are loudest in pretending to hear differences would probably miserably fail in blind tests and/or prefer cheap digital filters.

I suppose for people who are pretending, that might be true... but then there are the people who are not pretending and can actually hear the differences... that is another story.

I try to put it more clearly: when diagnosing "differences" there still remains the question if the difference is really an analog vs. VA difference or if the difference is due to different calibration / parameter setting.

[pdxindy]

When i read discussions about VA and analog, my overall impression is that those people who are loudest in pretending to hear differences would probably miserably fail in blind tests and/or prefer cheap digital filters.

I suppose for people who are pretending, that might be true... but then there are the people who are not pretending and can actually hear the differences... that is another story.

I try to put it more clearly: when diagnosing "differences" there still remains the question if the difference is really an analog vs. VA difference or if the difference is due to different calibration / parameter setting.

I consider that question settled. I can hear differences that are an analog vs VA thing. Emulation and the current nature of the medium are two separate things (that constantly are conflated)

Look at digital photography. There are still some situations where digital cameras have artifacts that film never would/could (Moiré patterns as one example). Those artifacts are the result of the medium and have nothing to do with whether that particular digital camera is attempting to replicate the color palette, tonality and grain of a particular film which would be emulation.

It is the same with digital audio. There are situations where digital synths have artifacts due to the medium... their own version of moiré patterns as it were. These artifacts are audible and if one understands the situations where they arise, easy to test for... same as it is easy to make a digital camera have moiré patterns if you try to.

None of this is to put a value judgement of better or worse on the two mediums. Simply that there are differences inherent to the mediums that are clear to the trained ear/eye. Maybe someone even likes the moiré patterns in digital photography. It is fine for them to like whatever they do, but that has nothing to do with the fact that the pattern is a digital artifact which makes it easy to tell in which medium the photo was taken.

[Arrested Developer]

@pdxindy:
as written, i don't say there cannot be audible differences between VA-analog, but that one has to take a closer look to see the cause of the difference.

[pdxindy]

@pdxindy:
as written, i don't say there cannot be audible differences between VA-analog, but that one has to take a closer look to see the cause of the difference.

Why does one have to?