Recent Posts

Pages: 1 ... 3 4 [5] 6 7 ... 10
PreenFM2 / Re: output routing
« Last post by Xavier 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: output routing
« Last post by Omnichordman on July 08, 2019, 09:38:19 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.
So I think it would be easier and even cheaper to put two Preens in one housing, for 4-channel FM.

PreenFM2 / Re: output routing22
« Last post by Omnichordman on July 08, 2019, 09:03:20 PM »

I am pretty new to the Preen, and I have the exact same question.
From what I can see on the schematics, the two DAC outputs on the MPC4922‘s, are summed to one op-amp each, so there would at least 2 more op-amps be needed.
I don‘t know if SPI_DAC1 and 2 can send stereo-Data, or if two more SPI_DAC‘s are needed.

Can anyone enlighten us?

PreenFM2 / output routing
« Last post by klangFM on July 07, 2019, 09:16:32 PM »
How can one  instrument play only at one mono output,
or how it can programmed to play all 4 instruments to 4 outputs individually?
I'm sure it works, but can't find it in Menu.
PreenFM2 / Re: custom extended firmware
« Last post by superfake on June 30, 2019, 06:02:48 PM »
Hello! Thanks for the work!  :)
But I tried an alternative firmware and found that the operators are working in free-running mode.  :o
And with its use, everything sounds much quieter.
This is normal?
I really wanted the operators to work with a fixed phase, as in the standard firmware, in order to use Preenfm2 as a 8 parts percussion module.  ::)

I did a test to show the difference.
First, the standard firmware plays.

PreenFM2 / Re: Random patch resetting - was yellow oled issue
« Last post by Road_Kill on June 29, 2019, 06:18:16 PM »
Xavier - Apologies for not replying sooner as this was a busy week. While I initially said I wouldn't be opening up the synth again until about this time, in fact I immediately turned around after my last reply and opened the synth back up! (Because who needs sleep when you could get a PreenFM up and running?)

The first thing I realized was that things were a lot more cramped with the insulated ground plate under the OLED than I initially thought. One consequence was that the wire coming from MCLK patching the defective trace was mashed such that it was possible intermittent shorts could occur with adjacent pins. And while I didn't see any evidence, I couldn't rule out random shorts occurring with solder joints piercing the insulation of the grounded shield. So I covered the circuit board under the shield with a layer of electrical tape, paying extra attention to really isolating the wire tacked to pin 6 of the 405.

I have been running the synth continuously since then, with and without sequencers running for many hours, and with as much hands-on as the past few days have afforded me. I think it's safe to declare this synth operational! So yes, it took you telling me to look at pin 6 to actually consider that might be the problem despite the big ugly wire hanging off of it. :P But now I've hopefully made the synth robust and if not, I know where to concentrate future improvements/modifications.

Once again,
Thank You!
PreenFM2 / Re: custom extended firmware
« Last post by observer on June 29, 2019, 02:55:03 AM »
would it be possible to merge these features with the official release? I love the custom cc's and the extended Program Change options and use them regularly, but with the added features of midi control of the display, and tuning selections, I'm so torn!  :o
PreenFM2 / Re: custom extended firmware
« Last post by kyoto on June 28, 2019, 10:07:06 PM »
thnx for your custom firmware  - great work!
How difficult is it to increase the frequency range of the parameter MASTER TUNE?
in your firmware range is (435 to 444)
sometimes i need 428 and 432hz

my post (Reply #140) in this thread

PreenFM2 / Re: Latest firmware : 2.10 (2019 june 13th)
« Last post by Xavier 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: Latest firmware : 2.10 (2019 june 13th)
« Last post by kyoto on June 25, 2019, 09:41:20 AM »
1) a little awkward  ::)
i saw on other topic custom extended firmware from lokki, his firmware has master tune parameter, but only with range 435 to 444.
I need a lower mastertune frequency, since I work with live musicians who tune their instruments for eample in 428hz and 432hz

2) the LP filter that is now in the firmware 2.10 sounds very dirty

it's easy to hear:
reduce the resonance parameter to zero
and gradually reduce the filter parameter
I hear that resonance still affects the sound

I understand that the filter is not the main thing that should decorate this synthesizer  ;)
but sometimes when creating patches of high frequencies there is a lot of and I would like to soften the sound a bit
I don't want to use external filters or vst plug-ins for this, I would like to have a good LP filter in the synthesizer itself  ;)

3) so we store user waves on the external storage, and there is enough space for storage

4) I hope in some of the releases you will do work with banks / patches

thanks anyway for the work done!
Pages: 1 ... 3 4 [5] 6 7 ... 10