Software samplers with real time sample rate conversion

Sampler and Sampling discussion (techniques, tips and tricks, etc.)
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ChamomileShark
KVRian
1416 posts since 12 May, 2004 from Oxford, UK

Post Mon Jan 14, 2019 3:35 pm

So this question comes from the assertion in this video (appx 10 mins 50sec) that hardware samplers sound different because they use real time sample rate conversion. While you can change the sample rate for a DAW project or within a soft sampler but it is fixed for that project.

https://www.youtube.com/watch?v=aDUMMOKY3jo&t=1825s

I'd be interested to know if that is actually true. Are there any software samplers that can do this?

Supplimentary question - if not, would a cheap hardware sampler like a Pocket Operator PO 33 offer realtime sample rate conversion?

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planetearth
KVRian
1473 posts since 10 Jul, 2006 from Tampa

Re: Software samplers with real time sample rate conversion

Post Mon Jan 14, 2019 4:42 pm

I think you'll find more people here arguing that it's the A/D and D/A converters (and analogue filters) that make hardware samplers sound different. I'd be inclined to agree with them. The pitch-shifting algorithms on hardware samplers also factor in to the overall sound.

For recording samples, you can change the sample rate of software samplers (though you may only get sample rates and bit depths your audio interface supports), but yes, the sample rate for a project is set within the DAW. And I haven't seen a "sampler" VSTi within a DAW project get around that yet.

If you're talking about changing the sample rate during sample playback (either for pitch-shifting or special effects), there are quite a few "sampler"/ROMpler VSTis which can do that. SampleTank and Kontakt are two top-name ROMplers that can vary the sample rate on playback. The Emulator X3 VSTi sampler offers this, too.

I guess it comes down to whether you're trying to change the sample rate to record grittier (and arguably, more "interesting") sounding samples, or you want to change the sample rate on playback for pitch-shifting purposes or other effects.

In the context of what Junkie XL is talking about (in the 10-minute area), yes, he's stretching samples across multiple keys, and varying the playback sample rate to make the sample play at the correct pitch. But I think he oversimplifies what Cubase or Kontakt do, because if you took a sample of a synth every 4 keys (or just one key, as he did) and loaded that in to SampleTank, Kontakt or Emulator X3, you'd basically be doing the same thing his Roland S-50 is doing. (Junkie XL even admits he's effectively using the S-50 to alter the sound of the Moog--not to recreate it faithfully.) The fact that Kontakt (or any other ROMpler VSTi) can allocate more RAM to one piano sample than the Roland S-50 had for all of its sample RAM means that developers can multi-sample the instruments they want to sample, to create "better"- and more authentic-sounding sample sets. ("Better" is relative, if you're craving the grittier sounds you can get from varying the sample playback.)

But in any case, having the S-50 pitch-shift the one sample he recorded over a couple of octaves will create the sound he gets based upon the algorithm it uses, the distance from the original sample note, the original sample rate, and the D/A converters. Take a one-note sample into Kontakt, stretch it across multiple octaves and you'll get a similar sound--minus the AD and DA converters and analogue filters.

Steve
Listen to some of my stuff here: https://soundcloud.com/shadowsoflife.

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EvilDragon
KVRAF
17714 posts since 7 Jan, 2009 from Croatia

Re: Software samplers with real time sample rate conversion

Post Tue Jan 15, 2019 12:11 am

All virtual samplers to realtime resampling as soon as you do any repitching operation (changing the tuning or stretching the zone in the mapping) to the sample.

One other difference compared to SOME hardware samplers, is that some had a DAC per voice, rather than one DAC for the whole system (in this case - your audio interface). That can and will certainly make a difference.

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BertKoor
KVRAF
10961 posts since 8 Mar, 2005 from Utrecht, Holland

Re: Software samplers with real time sample rate conversion

Post Tue Jan 15, 2019 9:01 am

^ what EvilDragon said, very true!
All software samplers resample to the sample rate of the daw project. Some hw samplers did not resample but change pitch by adjusting playback rate. That means no interpolation, thus high quality.
ChamomileShark wrote:
Mon Jan 14, 2019 3:35 pm
would a cheap hardware sampler like a Pocket Operator PO 33 offer realtime sample rate conversion?
What kind of effect / sound are you after?
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ChamomileShark
KVRian
1416 posts since 12 May, 2004 from Oxford, UK

Re: Software samplers with real time sample rate conversion

Post Tue Jan 15, 2019 10:03 am

hi, thanks everyone for your replies. Sorry I didn't reply earlier. And also apologies for not being clearer about the point of my post and what outcomes I was looking for.

Just to confirm, I am looking for that grittier sound by sampling one note and then (mainly) playing a lower note.

So in terms of hardware samplers I'm looking more at the same kinds of sounds that came from the CMI IIx, Emulator II - or maybe as grotty as the Mirage rather than pristine. I have Kontakt (which I use mainly to playback sample libraries), Halion 6 (which I use mainly to sample every note from a synth), TAL-sampler, Emulator X3 (a bit wobbly in Cubase, seemingly better in Bitwig) and even Cyclone (although I've not created my own samples within that).

I have zero experience of hardware samplers - they came along some time after I started making music and didn't really become affordable until after I didn't have anything to spend! I've looked at the vintage stuff wistfully since but knowing how basic my needs are and willingness to navigate the kind of OS they have, I've left well alone.

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BertKoor
KVRAF
10961 posts since 8 Mar, 2005 from Utrecht, Holland

Re: Software samplers with real time sample rate conversion

Post Tue Jan 15, 2019 1:18 pm

Fyi, the Mirage used only 12 bits, sampled at 32 kHz... (I think)
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audiojunkie
KVRAF
2760 posts since 19 Apr, 2002 from Utah

Re: Software samplers with real time sample rate conversion

Post Tue Jan 15, 2019 3:34 pm

You are looking for TAL-Sampler: https://tal-software.com/products/tal-sampler
C/R, dongles & other intrusive copy protection equals less-control & more-hassle for consumers. Company gone-can’t authorize. Limit to # of auths. Instability-ie PACE. Forced internet auths. THE HONEST ARE HASSLED, NOT THE PIRATES.

Etienne1973
KVRist
403 posts since 8 Feb, 2013 from Switzerland

Re: Software samplers with real time sample rate conversion

Post Wed Jan 16, 2019 9:10 am

He already has TAL Sampler. But I don't understand b/c TAL Sampler delivers Fairlight, EMUII etc. sound character.
ChamomileShark wrote:
Tue Jan 15, 2019 10:03 am
So in terms of hardware samplers I'm looking more at the same kinds of sounds that came from the CMI IIx, Emulator II - or maybe as grotty as the Mirage rather than pristine.

audiojunkie
KVRAF
2760 posts since 19 Apr, 2002 from Utah

Re: Software samplers with real time sample rate conversion

Post Wed Jan 16, 2019 9:27 am

Etienne1973 wrote:
Wed Jan 16, 2019 9:10 am
He already has TAL Sampler. But I don't understand b/c TAL Sampler delivers Fairlight, EMUII etc. sound character.
ChamomileShark wrote:
Tue Jan 15, 2019 10:03 am
So in terms of hardware samplers I'm looking more at the same kinds of sounds that came from the CMI IIx, Emulator II - or maybe as grotty as the Mirage rather than pristine.
Ah, yes. I missed that comment. I agree with you. If he is looking for that gritty old-school character, he's basically already got it. So maybe I don't understand exactly what is wanted either. :?
C/R, dongles & other intrusive copy protection equals less-control & more-hassle for consumers. Company gone-can’t authorize. Limit to # of auths. Instability-ie PACE. Forced internet auths. THE HONEST ARE HASSLED, NOT THE PIRATES.

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ChamomileShark
KVRian
1416 posts since 12 May, 2004 from Oxford, UK

Re: Software samplers with real time sample rate conversion

Post Wed Jan 16, 2019 10:12 am

hi, it is in my posts, honest.

I had asked about the "realtime sample rate conversion" used in playback when transposing a sample. It was what was mentioned in the video and was given as one of the reasons hardware samplers sound "better". I was then asked to clarify whether I was looking for best quality or vintage character.

It sounds from the replies that not all hardware used this method and some of the software samplers do this so to an extent the video is in error or overstating the influence of this factor.

I'm already familiar with the sample rate and bit depth for recording of various bits of hardware. I have some inkling of the different DAC types too.

moshimoshi
KVRist
85 posts since 18 May, 2016

Re: Software samplers with real time sample rate conversion

Post Wed Jan 16, 2019 12:43 pm

I'm not sure if any software samplers do this. Maybe Morgana? Tal Sampler is great at DAC emulation but I'm not sure if the sample playback is variable samplerate. Have a look at Permut-8, obviously this is just a delay but it uses variable samplerate emulation so you can get an idea of what this technique sounds like.

sleepcircle
KVRian
575 posts since 28 Nov, 2016

Re: Software samplers with real time sample rate conversion

Post Wed Jan 16, 2019 7:47 pm

TAL Sampler's sample playback is variable samplerate. the diagram on the main page shows how it works.

https://tal-software.com/images/product ... _emu_2.png

there are varying levels of at-play-time resampler quality, from "hq" to "the most nasty and basic 'sample hold' possible," but it resamples per individual note, as far as i can tell.
Last edited by sleepcircle on Thu Jan 17, 2019 4:12 pm, edited 1 time in total.

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ChamomileShark
KVRian
1416 posts since 12 May, 2004 from Oxford, UK

Re: Software samplers with real time sample rate conversion

Post Thu Jan 17, 2019 2:21 am

hi thanks. It seems the general opinion is that many software samplers do this at playback.

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nix808
KVRAF
3703 posts since 22 Jul, 2006 from Tasmania, Australia

Re: Software samplers with real time sample rate conversion

Post Thu Jan 17, 2019 2:39 am

hmm-
well in software,
to read a sample, we have PCM format, so like an array of points.
Then we scan the array of points to read it.
We employ a counter, wherever the counter is at, we read the PCM float value.
To make pitch 60, we read at counter speed five, to make pitch 72 we read at ten.
So old Akai samplers, they are real similar-
ie. some sort of digital implementation
I wouldn't worry about it(trying to be a vintage sampler)-
it should be so similar to any digital sampler(not that there is really an analogue kind(tape?))
So yeah--
use a sampler, they kick ass
I have been using 3 soft samplers this week

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fmr
KVRAF
8510 posts since 16 Mar, 2003 from Porto - Portugal

Re: Software samplers with real time sample rate conversion

Post Thu Jan 17, 2019 3:04 am

@ChamomileShark: I think you should read the series of articles written by Stephen Howell about samplers and sampling for Sound On Sound, titled The Lost Art of Sampling. IMO, you are chasing myths. There are seven articles in total. I leave you with the link to the first one:

https://www.soundonsound.com/techniques ... ing-part-1
Fernando (FMR)

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