Hydrasynth+Octatrack NRPN issue

Whats up y’all , hope we’re all doing well.

I’m having an issue sequencing/controlling the hydrasynth(desktop) via the octatrack(mk1) and really appreciate if anyone has any insight or similar xp

Hydrasynth only takes NRPN, midi is going thru rytm and Akeys before it gets to hydra

afaik, im doing everything correctly, CC 1-4 are as follows:
CC1- 98 (LSB) value : 68
CC2 -99( MSB) value: 0
CC3- 38 (DATALSB) value: 0-1
CC4- 6 (DATAENTR) value: 0-127

what Im trying to do is very simple to test functionality; control Hydras filter cutoff with P-locks on the OT, using CC4

hyrdas midi implementation guide http://www.mecldata.com/download/asm/Hydrasynth_MIDI_Implementation_Spec%20v1.4.pdf

it says there that MSB and LSB for filter 1 cutoff is MSB =40H LSB= 28H hence LSB value of 68

it doesnt work at all, there are infrequent random times where the data gets thru and the cutoff is modulated for one trig. other than that, completely non-funtional. anyone else have this experience ?

I’m always a little chary about using the Hydrasynth MIDI Implementation Guide.

First off, do you have the Hydrasynth set up to receive NRPN data? It’s on the System Setup page 6, #2 set to ON.

Then instead of the MIDI Implementation Guide, i’d recommend using the Hydrasynth itself, and send out and duplicate the data it sends. I use MIDI OX to look, and obviously you need to turn on NRPN transmit.

Here’s the data i got from my HS twiddling Filter #1 Cutoff:
Filter Cutoff
All the data is in Hex.

The guide is probably fine (though i found it incomplete in the past), it’s just that i’d prefer using a primary source.

If all that is fine, you need to verify somehow that this is the data that actually is coming out of the “pipe” to the HS.



Good on you for doing this. The HS is incredibly powerful using the NRPN, for instance changing multiple parameters simultanously with a custom set up Macro. Or playing the Ribbon control. Or whatever.

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yup all settings are in order for it to function, I’m afraid its not getting thru the pipe as you say.

I went directly from OT to HS to eliminate any potential midi corruption with no success. Then I remembered my rev2 takes NRPN also and tried it out, works perfectly as expected. must be something up with the HS, going to try to reach ASM about it :confused:

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I’m interested in hearing how this all turns out.

Sure thing I’ll update the thread, ty for your help :slight_smile:

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Any updates?

Your first problem is that you have the CCs in the wrong order: it should be 99, 98, 6, 38, as shown in the screenshot by @Jukka in a previous post.

No, it doesn’t. It says

  • NRPN MSB (CC 99) = 40H (which is 64 in decimal)
  • NRPN LSB (CC 99) = 28H (which is 40 in decimal)
  • Value MSB (CC 6) = vvH
  • Value LSB (CC 38) = wwH

The value can be anywhere in the range from 0000H to 2000H (which is 0 to 8191 in decimal). Therefore Value MSB can be in the range from 0 to 63 in decimal, and Value LSB can be in the range from 0 to 127 decimal.

So if you wanted to set Hydrasynth’s Filter 1 cutoff to its midpoint, you would have to send:

  • CC 99 with value of 64
  • CC 98 with value of 40
  • CC 6 with value of 32
  • CC 38 with value of 0

Depending on Hydrasynth’s MIDI implementation, you may need to send all 4 CC messages again in order to make another change.

You may be able to get coarse resolution by omitting CC 38 and only playing with CC 6.

BUT

No: Hydrasynth also responds to MIDI CC messages. Through its modulation matrix you can route any CC message to many modulation destinations: see page 75 of its manual. You may find it easier just to send individual CCs to the Hydrasynth from the Octatrack.

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You’re the best peter <3 ty

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