KVR Audio

Hello,

first I would like to thanks shutterdownmax for all his great tutorial on Surge XT. I've learned a lot.

I'm a newbie in designing sound with synth and I think I need a little help here.

I'm trying to make a patch in order to reproduce sound of Mellotron (MkII Violin). I'm starting from sample file obtained on the web for the C3 pitch. Then I've used WaveCleaver in order to obtain wavetable file. WaveCleaver can produce wt file (Surge XT compatible) or wav file (Vital compatible):
Then on Surge XT, starting from the "Duduk" MPE preset built by shutterdownmax I've build my preset : I'm not very satisfied with the sound it produce. So I went to Vital and I built a preset from scratch. Here is the result : Then I'm much more satisfied with the sound obtained.

Could someone tell me what I'm doing wrong with Surge since I would prefer to use this Synth as it is fully open source (Vital is not really open source and furthermore no update has recently occurred).

Once again I'm a newbie in synth sound design so if you found that the presets are not good please tell me but point me to the right direction in order to improve my skills.

Hi Phil!
My computers and I are very busy at the moment and I haven't had a chance to look at your patch, but I do have some (guesses and) thoughts for you. If you want it to sound like a mellotron, a wavetable is not the tool you want to use. It will not preserve the noisiness and pitch fluctuations that are integral to the mellotron sound. It would work better to take your initial sample (not the wavetable) and have the wavetable oscillator play it as a one-shot. It won't loop, but neither does a mellotron.

Also, the Surge Team is working on a sampler: https://surge-synth-team.org/shortcircuit-xt/
I haven't tried it and my understanding is it's in a very early and rough stage, but most likely it would be (or will be) a better tool for the job. It might even let you load in all of the MkII Violins samples and assign one to each key, which would give you a much better mellotron.

Thanks for the pointer to WaveCleaver, I might add that to the description of my wavetables video.

Hi Max,

I think you are right when you said that wavetable is not the tool to use in order to reproduce a mellotron sound. I've found the way to produce a one-shot wt (by simply dragging a my sample wav file to Surge XT) but as you said it won't loop. Too bad, because the sound obtained was pretty good. But playing long notes with high pitch is impossible because the sound generated is too short...

As I already discussed on the discord Surge XT community, one developer point me to ShortCircuit XT, now available as a beta version. I've tried ShortCircuit XT with my mellotron sample and yes, it's already very good. Furthermore it seems to be already MPE compatible.

I've just watched your last video tutorial (In which you talk about one-shot wavetable at hte beginning), and as usual it's very good and very instructive. One again thank you for this work.

Awesome, I'm glad you've got something working. FYI there's not a very small limit on how long your one-shot can be, so you could create a looped version of your sample and use that to reach the high notes. But I do think a real sampler like ShortCircuit is the best choice for something like this.

You said that I could create a looped version of your sample and use that to reach the high notes, but I think that the problem is that if I make a loop in Audacity the wav file is not "accepted" by Surge XT. I think this is mentionned somewhere in Surge XT documentation (but I don't recall exactly where).

Nevertheless, by reading the documentation one more time (Section Wavetable), I can read : "Surge XT can also import wavetables containing a clm block to indicate loop size (as used by Serum), a cue block (as used by various products including Native Instruments) and a smpl block. Wavetable files without loop information are loaded as one-shots.".
Is this is what you have in mind ? I don't know how to add this "loop size" information to a wavetable. Do I have to use Serum ?

Without those blocks, the looped .wav would not be treated as a wavetable, but just a one-shot, which is what you want to keep the mellotronness. If I understand, the loop size etc. are what you were using WaveCleaver for. Vital would also do this for you. But to make a long loop to be treated as a one-shot, audacity is all you need.

Max,

I'm not sure I understand your last post. What do you mean exactly by saying "But to make a long loop to be treated as a one-shot, audacity is all you need". What do I have to do in Audacity ?

I think I've found a way to obtain my Mellotron sound with Wavetables from C3 samples wav of MkII Violins.

Step 1. In Surge XT, Itit Patch and select WT for OSC 1.

Step 2. Drag & drop your wav sample to the wt window.

Step 3. Export the wavetable. This will produce a wav file in the Wavetables/Exported/ folder.

Step 4. Convert this wav file to wt file with this tool : https://github.com/iicaras/Wavetable-Tools-WTT
wtt.py wavtowt /UMRK/Synced/SurgeXT/Wavetables/Exported/file.wav
A nw file named file.wt is now available.

Step 5. Open with an hexadecimal editor file.wt and set the first values a indicated (see https://github.com/surge-synthesizer/su ... format.txt) :
76 61 77 74 00 10 00 00 00 02 02
- bytes 0 to 3 : 76 61 77 74 (text "vawt")
- bytes 4 to 7 : 00 10 00 00 (4096 samples)
- bytes 8 to 9 : 00 02 (512 frames)
- bytes 10 to 11 : 02 (loop)
Save the file.

Step 6. From Surge XT, Init Patch ans select WT for OSC 1

Step 7. Load the wt file obtained at Step 5.

Step 8. Set octave of OSC 1 to -3 and octave of Scene to -1

Step 9. Set Unisson Voices to 16 and Unisson Detune to 30 %

Here the sound obtained is very close to your sample.

Here his the patch :

Without commenting on the pros/cons of doing it various ways, a couple of things to clear up:

(1) Vital is really, truly open source. Unlike Surge it does not accept outside contributions, but it is 100% open source.
(2) Shortcircuit is very close to a stable 1.0 release! I would not classify it in rough shape anymore. It's pretty much feature complete now!
(3) When Max says Audacity is all you need, (I believe) what he is saying is to use Audacity to make the wav file much longer, looping a section to as long as you desire your note to be, and then bouncing it out. Then you load that wav file as your oneshot sample.

All that said, I would suggest Shortcircuit for this task. It's what it's meant for!

(3) yep, that's what I meant.

Ok,

so I've made this little test. From Audacity I've generated several tone (440Hz) with the following duration : 3 s, 30 s, 3 mn and 10 mn.

If I successively drop thes wav file onto Surge XT and then export the "produced" wt I obtain wav file with the following duration

Original duration (wav) --> WT duration --> Ratio
3 s --> 0.383 s (132 Frames x 1024 Samples) --> 7.832
30 s --> 3.756 s (1294 Frames x 1024 Samples) --> 7.987
3 mn --> 5.953 s (2051 Frames x 1024 Samples) --> 30.236
30 mn --> 5.953 s (2051 Frames x 1024 Samples) -->302.36

Maybe (2051 Frames x 1024) Samples is the max value supported by Surge XT ?

Furthermore, once for example the 3 mn wav sample has been dropped on Surge XT, if you play a note you will see that the sound is OK at the beginning and then a sort of saturation occur... What is the origin of this saturation ?

If you're doing the long wav method mentioned above, you aren't supposed to be using this as a wavetable, so you don't export anything as a .wt file. You're supposed to be using it as a one shot sample.

Even if you succeed in creating a wavetable that sounds like a Mellotron on C3, it won’t be close to a Mellotron on any other pitch. As mentioned before multiple times. Shortcircuit would be the tool to play Mellotron sounds. And that pretty easily…

Many thanks, shutterdownmax, Surgo and Tj Shredder, for all your explanations and advices.

Actually, I think you right when saying that wavetable synth will not be able to produce a sound close to the Mellotron at several pitches.