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Messages - Xavier

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PreenFM2 / Re: output routing
« on: July 09, 2019, 09:29:26 PM »
...I just saw, that the two 12-bit channels of the MPC4922 are combined for the 18 bit resolution of the output. So my educated guess is: the PreenFM2 is two channel audio out by design.


But you can redirect one instrumnent to one mono channel and a second one to the other.
Go to the mix engine menu, then turn right or left one of your op while holding down the mid left button. That will turn all mix* at the same time.


PreenFM2 / Re: Latest firmware : 2.10 (2019 june 13th)
« on: June 26, 2019, 01:30:41 PM »
Thanks for your interest ;)

2) I'm sure the LP filter is not very good as it's a simple formula (CPU light) i found on the web. A better one would be heavier and could unlikely be handled by the preenfm2 CPU without sacrifying some voices.
Writting good filter algorithms requires time and skills i don't have.
But if you find some opensource interesting ones, i can take a look.

3) All waveforms must loaded in RAM at runtime, so that the CPU can access them efficiently. RAM is much faster than Flash storage.
The RAM (192kb) is quite full. UserWaveform takes 24kb of them.


PreenFM2 / Re: Random patch resetting - was yellow oled issue
« on: June 25, 2019, 08:07:56 AM »
I'm not sure at all about your conclusion  ;)

Could you post high quality pictures of your PCB without OLED, both side ?

PreenFM2 / Re: Latest firmware : 2.10 (2019 june 13th)
« on: June 25, 2019, 08:03:55 AM »
Hi thanks for the nice words and thanks for the suggestions.

I'm afraid the replies to your questions are :

1. Yes but you can already do that with the scala file (not ideal i agree).
I think someone already made a custom firmware with this. I would need to merge it.

2. I don't think i'll ever do that. But who knows. FM synthesis should not rely on filters ;) even it's it's a good to have.

3. No it's limited by the memory of the preenfm2 which is already full.

4. No, that would be too much work.

PreenFM2 / Re: Random patch resetting - was yellow oled issue
« on: June 23, 2019, 10:54:36 AM »

I never heard of such a problem before.
All that sounds like bad solder joint or shortcut somewhere.

Maybe around the 74H165 and the encoder/button area with the 2 network resistors.
It can also be a ground problem that would make the encoder/button to randomly trigger values and the display not to be stable.

The only solution is to take time with a multimeter and verify carfefully all solder joints.

You can start by checking the voltages of the first schema here :

Then use the second one o verify the tracks that start at MCLK, MQH and MLD on the preenf405 to the 74HC165 et resistor network.


PreenFM2 / Re: Latest firmware : 2.10 (2019 june 13th)
« on: June 13, 2019, 11:09:17 PM »

A little new release 2.10 is available :

PreenFM2 / Re: reversed encoders problem
« on: June 08, 2019, 10:21:37 AM »
Thanks, I'll give that a shot! Looking at encoders.cpp I see that the inversed encoder may already be defined here:
   int inversedEnc = (encoderType & 0x2) == 0 ? 1 : -1;

This initialized the type of encoder by the value you put in the menu setting.

    Is that a different way of writing the inversedEnc = (k<2 ? -1 : 1); code that you mentioned? Or do I need to add that somewhere?

if you add that line 163, this override the initialization above.
And you'll have the 2 encoders 1 & 2 of one type and the encoders 3 and 4 of the other type.

PreenFM2 / Re: Programming help: Oscillator feedback?
« on: June 06, 2019, 10:04:13 AM »
Sorry that's a question coming from analog synth usage (sustain can be switched off so it become "one shot"). Thanks for your replies. I will try those envelop values.

To switch off sustain, use decay lvl 0.

Atk 0 Lvl 1
Decay 2.0 Lvl 0
Sust 0 Lvl 0
Release 2.0 Lv 0

PreenFM2 / Re: reversed encoders problem
« on: June 04, 2019, 09:24:38 AM »
Sorry to reply so late, i missed this one.

If you have different encoders on the same preenfm you have 2 solutions :
. unsolder you encoders and put 4 similar ones.
. compile a custom firmware. It's explained here :
And what you need to override inversedEnc variable here:
inversedEnc = (k<2 ? -1 : 1);
inversedEnc = (k<2 ? 1 : -1);
That should work.

PreenFM2 / Re: preenfm2 editor 2.08.4 (November 25th 2017)
« on: June 01, 2019, 10:56:28 AM »

Mac os and windows zip are here :

Mac :
VST are directory whos name suffix is vst.

Windows :
The VST are dll file that must be put in your VST directory.

PreenFM2 / Re: PreenFM Eurorack module
« on: May 30, 2019, 05:52:16 PM »
Ah makes sense!
great if you could keep it in mind :D

In the attached firmare you can chose 12, 123 and 1234 as the "CV instruments" in the settings menu.
MENU > Tools > Set > "CV inst."

Any one to test it ?
Thanks  :)

PreenFM2 / Re: any way to select timbres via midi?
« on: May 30, 2019, 03:09:57 PM »
It was simpler than expected.
I attached a new 2.10 firmware that adds :
. CC#119 : value 1, 2, 3, 4 select the current preenfm2 instrument. Display is updated.
. A new setting "Tools>Set> Current Ch." (after the "Midi ch") . It allows you to use a midi channel that is redirected to the current instrument. Default value is none.

That should allow you to easily modify and play the 4 instruments that are loaded.

For the currious the changes are here :

Let me know what you think,

PreenFM2 / Re: any way to select timbres via midi?
« on: May 30, 2019, 02:44:59 PM »

I'm thinking also about adding a midi channel (modifiable in the settings) that would correspond to the current instrument.
That could be usefull.

PreenFM2 / Re: Is it possible to connect a 12v battery?
« on: May 30, 2019, 09:58:35 AM »

A 12v battery would make the 7805 (5v converter) super hot.
9v is the maximum you should use.

Yes it can work with up to 30v but only if you need very little current output.
With the preenfm2 9v is tht max if you don't want it to get toot hot and die.

PreenFM2 / Re: any way to select timbres via midi?
« on: May 30, 2019, 09:56:10 AM »
I'm trying to understand exactly what you need here.

I love this synth, but I find jumping between patches and timbres to be the most cumbersome part of working with the preenfm2.

So for timbre :
A new midi CC whichi accepts 4 values (let's say 1, 2, 3, 4) and will change the current instrument of the preenfm2 (display).
Did i got it ?

You also talk about patches ? What do you mean ?

I 100% agree. Any update or progress on this? Also loving the Preen but I also would love to be able to easily switch between Preen presets with a midi controller foot switch so I can seamlessly switch presets when performing.

Kelanimal, do you want to switch between preset (bank) or between the preenfm2 4 instruments ?
For preset, the preenfm2 responds to control change and you can also specify which bank

Can you give more info on how you would like it to behave ?
Maybe let me know an other synth that works better.

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