KVR Audio

Urs · Post by **Urs** » Thu Oct 28, 2010 6:35 pm

Ok, started a new thread for this:

http://www.kvraudio.com/forum/viewtopic.php?t=301170

antto · Post by **antto** » Thu Oct 28, 2010 9:34 pm

brighter at the lower notes.. this is the result of having a HP filter on it

Urs · Post by **Urs** » Thu Oct 28, 2010 9:51 pm

antto wrote:brighter at the lower notes.. this is the result of having a HP filter on it

Well, the hp filter is obviously tuned to the oscillator.

The bass notes do have a tad more content beyond 5kHz than the mids. This can easily be achieved by adding a 1st order LP into it for higher notes.

I suspect that both filters are put in place to cover aliasing. At low notes the aliasing is inaudible, at higher notes the aliasing below the fundamental is filtered by the hp filter. At the same time the "high grit" gets louder in the upper registers so the LP filter is used to drain this out too. The upper mids are loud enough to mask most of the aliasing, so they simply left that in.

It's noteworthy though that the waveform isn't a perfect saw and has audibly more 2nd, 3rd and 4th harmonic (maybe compensated for by resonance in the hp filter), but falls quicker towards Nyquist.

antto · Post by **antto** » Thu Oct 28, 2010 9:58 pm

uhm?
it doesn't sound right.. i don't know..
i had the same first experience trying to mimick the 303 oscillator waveforms at first
but at the end - it was all very simple and i was totally overcomplicating it at first..

this synth.. it's digital, right?
you say there's a HP filter tied to oscillator frequency? then, it's not a HP filter, it's a shaped sawtooth table

can i have a peek at the audio you're analysing?

Urs · Post by **Urs** » Thu Oct 28, 2010 11:54 pm

antto wrote:uhm?
it doesn't sound right.. i don't know..
i had the same first experience trying to mimick the 303 oscillator waveforms at first
but at the end - it was all very simple and i was totally overcomplicating it at first..

this synth.. it's digital, right?
you say there's a HP filter tied to oscillator frequency? then, it's not a HP filter, it's a shaped sawtooth table

Nah, I don't think it's a wavetable. It's one of those nifty little tricks like a half-sine waveshaper on a naive ramp. Google for Antti's paper from this year or last year. He describes a synth for low-cost dsps with some really intrigueing concepts.

can i have a peek at the audio you're analysing?

I'm using a JP8080, an oscilloscope and my ears. Havn't sampled anything yet. Most of the time I'm pitchbending notes in the upper octaves to study the aliasing behaviour. That way one can often guess the harmonic content better than looking at some obscure fft output. The lack of aliasing below the fundamental is a clear hint at the highpass filter.

Someone posted very nice examples of the JP in the dsp forum some time ago.

antto · Post by **antto** » Fri Oct 29, 2010 4:49 am

if you ask me.. look at the lower notes of a single sawtooth..
if possible - disable all filters to make the signal path minimal

Howard · Post by **Howard** » Fri Oct 29, 2010 10:58 am

olikana wrote:...the virus only recently introduced the hypersaw

2004 != "only recently"

Howard · Post by **Howard** » Fri Oct 29, 2010 11:06 am

Urs wrote:I did a bit of experimenting today. Would that be close enough?
http://www.u-he.com/music/supersaw.wav

Yes

Howard · Post by **Howard** » Fri Oct 29, 2010 11:10 am

Urs wrote:The bass notes do have a tad more content beyond 5kHz than the mids. This can easily be achieved by adding a 1st order LP into it for higher notes.

Are you sure that it's not just a volume-thing i.e. that low notes are simply louder?

Urs · Post by **Urs** » Fri Oct 29, 2010 11:50 am

Howard wrote:
Urs wrote:The bass notes do have a tad more content beyond 5kHz than the mids. This can easily be achieved by adding a 1st order LP into it for higher notes.
Are you sure that it's not just a volume-thing i.e. that low notes are simply louder?

Nope. I'm certain.

Architeuthis · Post by **Architeuthis** » Fri Oct 29, 2010 4:41 pm

adamtrance wrote:I was gonna keep this for myself a bit longer, but what the hell, I wanna tease a bit. Its in alpha stage:

Urs is apparently working on a JP8000 emulation + extras for sound quality as an add-on for Zebra. But, I don't know if I want to be a Zebra owner just yet if it turns out it's better than Helix's supersaw.

At the same time, I don't like synths that have just the basic set of controls of 2 LFOs, 2 ADSRs, 2 oscillators, and only 3 filter types and some basic distortion thrown in. I like unlimited-control synths like Zebra, Surge, Helix, KarmaFX, etc, so the price will be very important. Being able to put keyboard tracking on just about anything is really awesome. If anything, please don't scrimp on modulation features.

If your synth sounds better than Helix and has a good set of controls and features, I'd sell Helix and buy your synth in a heartbeat. Helix's other features don't mean much to me when I have KarmaFX Synth, it's only the supersaw that keeps me coming back to it.

Urs · Post by **Urs** » Sat Oct 30, 2010 12:18 pm

Architeuthis wrote:Urs is apparently working on a JP8000 emulation + extras for sound quality as an add-on for Zebra.

It isn't decided yet. I'm rather thinking of an easy-to-use 2VCO->VCF->VCA synth that has pretty accurate models of various oscillators (Sh-09, Juno 60, alpha Juno, JP8000 and then some) combined with pretty accurate models of various filters (Minimoog, Sh-09, MS-20, SEM and then some), various closely modeled ADSR generators and a whole bunch of uhbikal effects thrown in. However, each of the components would be modeled to exceed the natural ranges of control. I have a lot of these things sitting idle in my drawer. Would be good for either Zebra or such a minisynth (as requested by many, many people who find Zebra and even ACE too intimidating), or both.

Architeuthis · Post by **Architeuthis** » Sat Oct 30, 2010 4:57 pm

Bottom line is I won't be able to resist good sound quality whether the synth has lots of features or just enough to get by; so whatever anyone comes up with, if it sounds good, I'm buying.

pdxindy · Post by **pdxindy** » Sat Oct 30, 2010 6:54 pm

olikana wrote:
no i'm not. and don't need u to tell me that supersaw is stacked saws. doh!

yes he does... cause you keep missing the point... unison does not = supersaw

they sound different. they are different.

pdxindy · Post by **pdxindy** » Sat Oct 30, 2010 7:01 pm

Architeuthis wrote:Here's my problem with your and Urs' statement. The problem is that I find supersaws to be the most amazing synthesizer sound (maybe even most amazing sound period) I've ever heard. That is why my search for the perfect supersaw will continue indefinitely. Supersaws can create all sorts of beautiful pads, leads, basses, strums, acoustic imitations, etc. I describe a supersaw as something heavenly, angelic, fantastical, powerful, raw, biting, searing, stabbing... To me, a supersaw is for electronic music like strings are for orchestra.

Edit: So point is... don't tell me your synth can't do supersaw (or whatever term is being used these days)!

So you would prefer a developer tell you it can do supersaw sounds even if it cannot so you can go waste time on your search... you're daft man!

oh nOeS!