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hey... no I haven't gone any further in depth with it really as I've had my hands full with other stuff. If setting up listening tests though I suppose a thing to keep in mind is trying to do it in ways where it's easy for you to focus.. ie, perhaps the same chord or note in repetition playing from a midi file. When I did the test above I recorded many hits using a spectral analyzer as reference to select the brightest ones to compare so I wasn't foolishly just comparing a bright take with a darker one. How much tonal variation there can be between hits depends on the patch though. Maybe I didn't have retrigger on. Anyhow.. dive in there and see if you can expand on that area!

Incidentally - there is a discrepancy in the behaviour in some circumstances between 44.1 kHz and 48 kHz - which I would put down to being a feature of the Virus... It's by no means a physical limitation. Also, the difficulty in reproducing it also demonstrates what a fringe issue it is.

wtf? difficulty in reproducing it? You really don't seem very good at understanding things man and I have no idea what on earth you are doing repeatedly involving yourself in the topic in this and other threads. Pick a topic you actually know about if you feel the need to comment. It keeps things focused and saves the time of people having to correct you.

Recording a bunch of notes and then taking care to select the brightest one recorded at each sample rate just allowed for accurate comparison. It might have just needed retrigger to be turned on to make that part easier but I can't remember as I recorded that ages ago. It would be better to do with retrigger on. .

I know you're slow and seem to like being corrected, but being limited by the filters at 44khz vs 48khz is a PHYSICAL LIMITATION. It's the primary limitation you are hearing on that sound which isn't even a high sound. It's a 147hz saw. I often end up having to use filters with less poles just to keep the blanket off the top end. The 4 pole sounds great but is often just too dark for me to be able to use.

I think it would be useful to check the the classic oscillators as well as the wavetable oscillators in classic wave shapes, since the classic oscillators algorithm generates some aliasing, an it could be that the brightness you experience in 48kHz is just added aliasing. Also, the method of "cherry picking" the sample is not very scientific. It would be much more reliable to average the samples, for example. I am not familiar with the term "retrigger" in the context of the Virus, could it be something that I overlooked?

No, I know how to pick 2 proper samples for comparing, which is exactly why I did it out of 15 or so hits and had a spectrum analyzer, oscilloscope, and tuner on the signal to confirm. Handling that kind of thing is a walk in the park for me. What I should have done was made it easier by turning on the OSC retrigger (osc phase init) but like I said this was a while back and I gapped on that. The brightness at 48khz is absolutely not added aliasing. Aliasing works the other way around, lower sample rates = more aliasing in the audible band. High and clarity/openness/air are the most commonly observed attributes when people compare 44khz vs higher SR. On 44khz the antialias filters are affecting the audible band. At 48khz the filters are raised enough that it's a lot less audible. At 88khz the filters & aliasing are raised so high out of hearing rangte that they disappear.

While the wavetables do alias less, the filter on the Virus might play the biggest part here since you can't open the filter as much at 44khz as you can at 48khz. It has to work within its limtations.

I'm sorry NMS, I didn't realise you were an expert on ADCs and DACs - here was me thinking that with a basic interpolation filter on a 44.1kHz DAC you could comfortably represent all audible frequencies with near-zero attenuation and phase distortion - but obviously you know better despite most likely not having any experience in DSP system design. The example you produced - the prevalence of which we don't yet know - cannot be explained simply by looking at the sample rate and MUST be due to a feature of the software on the Virus - be it the resampling algorithm to generate the waveforms at different frequencies, or downsampling after oversampling stages in the signal chain (ie an intermediate AA filter). It could also be differing rounding error in the coefficients used for any of the signal processing going on in there.

If you have audible aliasing at 44.1 kHz you are doing something wrong (which I would doubt) or you've had to make a compromise to squeeze more performance out of the system (probably) - at 48 kHz you have no excuse as the guard band is massive. Beyond that you are full of shit. But like I said - believe what you want. The more people believe this nonsense the more room there will be for competitiveness. The memory and processing power requirements of increasing the sample rate are devastating which is why you would only upsample for physical modelling if you have some awkward difference equations to implement (like the virus does, of course), but an interpolation algorithm, rather than upsampling the signal wholesale, can (and has been, for me) very effective.

Also, I never said the 'added brightness at 48 kHz' is due to added aliasing - but I might have said the difference was down to an anti-aliasing or interpolation filter, depending on whether its a downsampling stage or the DAC stage, the latter being irrelevant for USB or S/PDIF audio.

At any rate I don't appreciate the offensive language and it's not in the spirit of this place - I'd spend more time demonstrating why you are wrong and how ignorant and foolish you look by being so rude, but I have a signal processing platform to finish developing before I finish my PhD in DSP so I'll leave it where it is. You can troll more if you want, and I'm sure you will, but no amount of boasing about how plugging something into a spectral analyser is easy for you (as if it would be difficult for anyone ) will change the fact that a lot of very qualified people (not slow people who like being corrected as you so eloquently put it) chose 44.1 kHz as a sample rate for CD audio with very good reason and that 48 kHz is enough of a concession to relax the requirements of SRC by having a huge guard band (4 kHz!) whilst keeping the bandwidth low.

All the while forgetting that almost nobody can hear 18 kHz, let alone 20kHz anyway!

Quoted from "AtonyB"

If you have audible aliasing at 44.1 kHz you are doing something wrong

So now aliasing doesn't exist? Access nailed alias free digital synthesis (that needs no help from running the synth at a higher rate) 15 yrs ago? Are you serious? Are you aware of the statement that's been made that the wavetables are significantly more alias free than the 15 yr old classic oscillators? Do you live under a rock oblivious to how much progress has been made in the last 10-15 yrs on digital synths and that aliasing is one of the biggest areas of improvement?

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The memory and processing power requirements of increasing the sample rate are devastating

Dcam synth squad and The Glue (2 of the highest regarded plugins ever made) both offer realtime oversampling up to 32x. Welcome to 2012. And you're acting like 88khz is overkill and "devastating" to implement? Seriously, no offense intended I just genuinely want to know.. do you actually live under a rock?

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At any rate I don't appreciate the offensive language and it's not in the spirit of this place - I'd spend more time demonstrating why you are wrong and how ignorant and foolish you look by being so rude

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Beyond that you are full of shit.

Classic.

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All the while forgetting that almost nobody can hear 18 kHz, let alone 20kHz anyway!

Cool! And how about the blanketed top end of those comparison files? I can hear the difference playing off my iphone speaker.

It's obvious to anyone reading that you passed the point of annoying long ago and have genuinely no business in this thread or any thread where people are expressing their desire for 88 or 96k operation of the Virus. None at all. You want to tell people that they shouldn't want what they want, but you are absolutely no one of any status or experience level to be telling them they're wrong for wanting it. If you find me rude it's because you've been an anoyying fly buzzing around this issue for ages spouting crap and backing up your words with nothing when you have no interest in having this functionality for your own use. I like my Virus too, but I don't feel the need to go "THAT'S A FEATURE NOT A LIMITATION!" when it comes to its shortcomings as if it's the most perfect synth that will ever grace the earth. Do you think the next Virus won't be able to operate at 88 or 96k internally? Guess again! Not in today's market.