Messages

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preenfm2 and preenfm3 / Re: USB noise - cheap solution!

« on: April 20, 2018, 06:26:11 AM »

Just leaving a note for others that might be searching up this topic:

This approach also worked for me: Remove Jmp2, then use the PSU for power, and USB just for MIDI - removes all the noise I was hearing on the audio outs when I was using just USB alone for both power and MIDI.

My unit is a van daal built unit, but it wasn't too hard to open it up and remove the jumper.

2

preenfm2 and preenfm3 / Re: Latest firmware : 2.08b (2018 April 1st)

« on: April 02, 2018, 09:27:47 PM »

The release on github is tagged incorrectly: 2.08b tag points to the same commit as 2.08a

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preenfm2 and preenfm3 / Re: Manual in PDF format

« on: March 12, 2018, 03:17:01 AM »

Thanks for this!

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preenfm2 and preenfm3 / Re: Volume mixer

« on: March 04, 2018, 12:42:54 AM »

The performance mapping thing is a work around... but you lose 1 or 2 performance parameters when you do that, and you don't have a quick and easy way to balance the parts.

I'm running the PreenFM2 live where MIDI sequencers and loopers are feeding the four instruments. As I'm playing, being able to quickly adjust the mix between the parts is important.

My set up using an external MIDI controller with eight encoders: The left four encoders are always the volume of the four PreenFM2 instruments (currently using the Filter Gain CC). The right four encoders are the four performance parameters, and there are four bank select switches to select which PreenFM2 instrument it controls.  This lets me tweak the performance parameters of an instrument as it is playing, and if that changes the volume significantly (they often do), I can quickly adjust the mix between the other instruments.

I should probably make a video fo this....

5

preenfm2 and preenfm3 / Re: Volume mixer

« on: March 01, 2018, 04:41:11 PM »

Reading through the source code, I discovered that there is already a CC mapped to volume, it just isn't obvious:

CC 73, Filter Gain, is actually gain¹ no matter what filter or final effect mode is selected, even none.

If Xavier's intention is that parameter always be simple channel gain as part of any future effects, then this parameter could be used for a in-box mixer mode, as well as externally.

I suppose if I were to attempt to code this (which I might), I'd be tempted to put an additional, per-instrument, pan and gain stage after the filter. I don't think it would cost too much in processing, and it would leave the row of filter parameters alone for future filter use. I would also be likely to implement a "constant voice gain" mode so that number of voices doesn't change the relative volume of an instrument.²

In the original post, there is a fx level. I suspect the intention was wet/dry. This doesn't exist in the synth. calculations today, but could be easily added (just another two multiplies and an add per instrument.)

Thoughts?

1: This filter stage gain calculation is linear. This gives a rather unnatural feel to the control. I'd think a quadratic response (squaring the gain) would yield a wider usable range, with a more natural feel, where the user can feel the control as scaled dbs.

2: It is understood that in a "constant voice gain", an instrument with but one voice would be 1/8 the volume it could be - thus losing some available range on the DAC if it were the only instrument. Personally, I'd be willing to give up these 3 bits in exchange for constant leveling of voices: one voice in a mono instrument is as loud as a single voice in a 3 voice instrument.

6

preenfm2 and preenfm3 / Re: Volume mixer

« on: February 18, 2018, 10:05:43 PM »

yeah, I guess I would set as if all 16 voices were playing... So playing a single voice is giving up almost 4 bits of the DAC's range, so from 18 bits down to 14. But that's still a tremendous dynamic range for a single voice. I'd be surprised if it were a problem....

But, one approach would be - assuming you have a "master instrument" mixer like O.P. in this thread proposes - and assuming that is scaled so that you can achieve +/-12db (say). Now, if the output of each instrument is fixed to the maximal polyphony possible, then.... if you are only playing one instrument or just one voice, you can use this mixer page to regain those bits in the conversion.

7

preenfm2 and preenfm3 / Re: Volume mixer

« on: February 18, 2018, 08:08:37 AM »

Other thing I noted today related to this: The volume of an instrument is reduced as you add more voices. This is done in an attempt to get the most dynamic range out of the DACs...

But in live work, this is very awkward: If I'm playing live and I decide to adjust the voice allocation - sometimes I like to up a bass sound from 1 voice to 2 - now I have to fiddle with other parameters to make it balanced again.

The 18-bit DAC has plenty of head room - it would be nicer to have a voice have a constant volume.

8

preenfm2 and preenfm3 / Re: Volume mixer

« on: February 17, 2018, 10:38:52 PM »

+1

I was just coming here to suggest pretty much the same thing.
While performing live, I need a quick way to adjust the balance of the four instruments.

For me, volume is the only important one. Pan might be nice.
Fx level I can see as being difficult, in so far as it might interact with the patch... and not sure there is but one "fx" control to use?