PreenFM mk2 : Continuing the discussion from the Mutable Instruments forum

[randy]

Not sure how many people here are also Shruthi alumni but there has been an ongoing discussion on the MI forum regarding Xavier's great little PreenFM synth.  The last reply from Xavier was:

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What a big thread… there’s more discussion here about the Preen than on its own forum ;-)

I don’t have any secrets, so here is the status.
I stopped packaging PreenFM kits because it takes me too much time beside my 3 kids and my full time job.
I shipped around 90 kits and 30 PCBs and am very happy that most people like it and find it usefull.

I don’t have anymore PCB and i’m not sure it’s worth it to order an other batch… Have to order many to have a decent price.
But anyone can do it.. gerber files are online.
You can also take the Kicad source and improve the routing.

But right, like many of you i’m DIY addicted, i cannot stop and I’m working slowly on a PreenFM mk2…
Don’t expect anything before mid 2013. I said slowly ;-)
I’m using a new board (cortex-m4 based) and don’t use any more the libmaple library… so that’s a lot of work.

Please if you have any questions, you can do it on http://forum.preenfm.net

Thanks for the interest,

Xavier

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When I originally started the thread, I was looking for some opinions on the PreenFM from the MI bunch, and the thread has morphed into all sorts of technical discussions.  I have since bought a PreenFM kit and have been using it for the past month or so, it's great!  So, I figured I'd try and get the discussion moving over here.

Randy

[Fitvideo]

I am looking forward to building mine, and dipping into and possibly contributing to the forum here.
regards

[funkyfli]

Oh...  Can't wait!
Will this newer chip give you room to implement some anti-aliasing?

I would love to see phase distortion in a diy synth.  At least one where you could edit the phase 'envelope' of the sine wave and create your own oscillator shapes.  Of course, this wouldn't be FM anymore. 

Martin.

[Xavier]

I'm not sure it will have any kind of anti-aliasing... i've never really worked on this problem.

Does any-one find the volume knob usefull ?
I'm thinking of getting rid of it and adding a 8th push button.

[funkyfli]

I've used the volume knob.  Most of the time it is at maximum.  I won't miss it.   

[randy]

You could always make it optional, like Olivier did on the Shruthi.  I have included it on the Shruthis I have.

Randy

[Xavier]

Yes, maybe optional.
But as the mk2 will be stereo, removing it would simplify the schema.

I cannot find a use case where the volume is not to the maximum.

[randy]

When I play live, I am constantly adjusting the volume based on the patch I'm using.  We don't have a soundman and the mixer is on the other side of the stage, so I keep a small monitor near me that has the same mix as the FOH mix. 

If you have a mixer handy and everything is running into it, adjusting the various volumes is easy enough but if the mixer is not that handy, a volume pot is essential.  My mixer is old and a bit tucked away, which is why I put output gain pots on my Shruthis.

Of course, this is just me, not sure about everyone else.

Randy

[Xavier]

That's a use case... thanks.

[randy]

Only one 'though.

[Fitvideo]

As i have not built the PreenFM yet i can only say I would find it useful rather than diving to the mixer all the time.
That's two
cheers

[shiftr]

I think a volume knob is very welcome function on any instrument... I really miss them on the shruthi's. It's also nice to be able to fade in/out instruments while playing and not having to go through the mixer.... And even more so using them connected to multichannel digital audiointerfaces wich often don't have a dedicated gain knob for every input and having to go to a software mixer.
What are your plans for the mkII? stereo is great! ... you should have a look at the DX7II ... i've owned one and it is veyr very fat...
things like layering 2 patches or all voices unisono with detune.
Also having played  a bit with the PreenFM i hope you can make the preenFMmkII sound a little bit more warm... The DX's are also really good at warm sounds and getting evil metalic sounds is always easy with FM. The preenFM now is especialy good at sounding evil but it;s hard getting more warm and soft sounding patches... I don't know why this is .... Maybe because it's working in integer? Are you making the preenFMmkII work with floats?

[Xavier]

Thanks for letting me know the volume button is usefull.

Moving to float is one of the goal... as the cortex-m4 MCU can do that.
Dont know exactly what the consequences will be on the sound. I haven't ported the engine yet.

[ByteFrenzy]

Personally I wouldn't really miss the volume control all that much. I run alll my synths into a DAW and I can control all volumes from there. And if you really need a simple way of controlling volume without a mixer live, I would probably run it through a volume pedal. Would it be an option to control volume with a cc ? Then you could just assign some buttons from your controller to volume up/down and maybe even some volume presets.

[Fitvideo]

 the one thing missing on Olivier's Shruthi is a volume control, it is way too loud , Inearly killed 10 people at a Leeds UK meet with it. ;-) Made a few heads turn. A volume control on any device is there so you know what likely level is coming out before it hits a mixer/daw. I don't use a DAW on stage either, but cc vol change is worthwhile to integrate with my foot controllers. good idea.

cheers