Messages

16

preenfm2 and preenfm3 / Re: Compressor/fuzz effect

« on: February 02, 2016, 05:11:30 PM »

I'll share firmware binary as soon as I get home.

I have some basic knowledge of dsp, and this is first usable audio thing I've done

But I plan to make some more sw modifications on preenfm2, namely on keyboard stack/circular buffer - voice allocation (as soon as I figure it out ). Not so important when using sequencers, but more so when playing on keyboard.

17

preenfm2 and preenfm3 / Compressor/fuzz effect

« on: February 02, 2016, 12:30:00 AM »

Hi everyone!

I've managed to add some kind of simplest possible compressor/overdrive/fuzz effect to preen. This probably doesn't need its own thread, but I didn't know where to put it, so here it is.

It has two parameters, threshold and compression ratio, and gain is automatically normalized to maximum gain (using advanced high school mathematical sorcery). With maximum compression ratio (0.0), and minimal threshold (0.0), this effect becomes fuzz. Ratio == 1.0, input signal is unchanged.
Parameters are changing linearly with encoder rotation, which may or may not be a good thing...

I've attached patch here, for anyone who thinks it may be of use to them (distorted B3 hammond anyone )
I've also attached firmware binaries (optimized and non-optimized), for easier trying out.

Compressor can be chosen in filter section, it is last in the list. Feel free to ask any questions, suggest or whatever comes to your mind.

Cheers,
Djordje

18

preenfm2 and preenfm3 / Re: Building firmware problem

« on: January 28, 2016, 08:50:17 PM »

Thank you,

it seems that just using GCC 4.7 fixed the problem with unwanted distortion. I didn't try to build earlier version of bootloader, as this solved my problem, but I will try it on the weekend.

It is really great how you've managed to cram so much synth in so little mcu

On a side note, I am adding some really simple overdrive/compressor/distortion thing fx, to compensate for varying perceived volume of different patches which is important for live sessions.

Cheers,
Djordje

19

preenfm2 and preenfm3 / Building firmware problem

« on: January 28, 2016, 01:59:02 AM »

Hi everyone!

Does anyone have problems with building firmware from source? (I hope this is right place for this question)

I noted two issues:
1. bootloader doesn't get built, first error I get is line "Erreur (((" in file ./src/filesystem/UsbKey.h:33

2. firmware gets created nevertheless, but it is smaller in size than official downloadable version (I suppose because of lack of bootloader), and I get strange distortion when playing whatever patch on preenfm2 (flashing succeeds, of course).
It works perfectly with official downloaded version.

GCC I am using, from launchpad.net:
$ arm-none-eabi-gcc --version
arm-none-eabi-gcc (GNU Tools for ARM Embedded Processors) 5.2.1 20151202 (release) [ARM/embedded-5-branch revision 231848]
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

and preenfm2 git commit 507e3649703c05a8c7454d28ec027dd634c11e4c from Oct 15th