[sdiy] picsynth? anyone built it here?

[Tom Wiltshire]

On 26 Mar 2009, at 13:25, Dan Snazelle wrote:

> The more I look at the PICSYNTH the more i want to try it

Go for it!


> my main concern however is with the keyboard required.
>
> i have a bunch of old  thrift store keyboards but i am not sure if  
> they are the right kind or have enough keys

"Not enough keys" isn't a problem for the synth. You could build it  
with one octave if you felt the urge (bass pedals perhaps).

> 1. do these need to be resistor or diode style?

Diode matrix style.

> 2. how many keys

The schematic has 4 octaves, but you don't have to wire them all up,  
so this is a maximum, not a minimum.

> 3. beyond that , are there any instructions on how to do this? I  
> couldnt find any on the PICSYNTH site.

No, neither could I, but matrix keyboards are all pretty much the  
same and we'll all help you!

> 4. is there a way to also add expo control somehow? this may be way  
> more complex than would be worth it but it is too bad you cant  
> control the pitch  with cv as well as the keyboard

In theory, you could repurpose the "OSC1 Tune" CV input, but it'd  
involve modifications to the code, which isn't provided.
So no, there's no way to add a CV input.


> if it could be, than a multi oscillator synth could be made quite  
> compact...or am i wrong?

Now you've got me wondering whether you could parallel up the two  
keyboard matrices somehow. I can't see another way to do it, and I  
can't see right now whether that's feasible or not.

Still, the PICSYNTH is a nice little project. I was impressed how  
much they got out of so little.

T.