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Topic: Soulsby Atmegatron Synthesizer (Read 1 time) previous topic - next topic

paulsoulsby

Just thought I'd use this forum for a bit of shameless self-promotion of the synthesizer that I'll soon be releasing.  It's based around the Atmega328P and Arduino platform.  It'll all be open source, so the code can be tweaked and uploaded.

This vid is probably better than me writing a 3 page essay on it!  http://youtu.be/o9RU6FjQdG4
If you're interested in it, please join the mailing list:  http://eepurl.com/FQIYL
and the facebook page too!  https://www.facebook.com/soulsby.synthesizers

Paul

fungus

Nice...

...but the output sounds very clicky in the video.

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

paulsoulsby

It's never going sound super smooth like a Moog or something.  But it's not supposed too.  It's 8-bit and trying to do an almighty amount of processing at only 16Mhz! 
Check out the demos and you'll hear that it sounds great!!  https://soundcloud.com/soulsby-synthesizers/sets/atmegatron-demos

fungus


It's never going sound super smooth like a Moog or something.  But it's not supposed too.  It's 8-bit and trying to do an almighty amount of processing at only 16Mhz! 


:-)

The clicks are barely noticeable in that track. There's some really nice sounds...

The really annoying clicks in the 'sneak preview' video are the sort  you can hear between 1:50 and 2:00 when the sounds shut off. To me it sounds like you're changing the volume at non-zero-crossing-points in the waveform (you should only change 'volume' when the wave crosses zero).

No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

paulsoulsby

Ah yes, I see what you mean now.   Yes unfortunately it can't detect zero crossing.  The interrupt used for the audio has to loop around the wavetable as fast as possible.  Even a few lines of code to check for zero crossing would be too much   :(
However you can put a very short attack and decay time on the amplitude envelope which will sort this out.   I had both times set to 0 for that demo.  Maybe I'll change those values for the default sound.    ;)

fungus


Even a few lines of code to check for zero crossing would be too much   :(


It really, really makes a big difference to overall sound quality.  :)

XOR the sample with the previous one, see if the sign changes...update amplitude if so.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

paulsoulsby

Quick update:

Final product details for the Atmegatron can be found here:
http://soulsbysynths.blogspot.co.uk/2014/01/atmegatron-goes-on-sale-3rd-march.html

A new video showing the finished Atmegatron Complete in all it's glory can be found here:
http://youtu.be/TyapZZPuqoo

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