Maestro Filter + Sample & Hold

[DanielWong]

http://tonepad.com/getFile.asp?id=96

At the left-lower of the schematic, the up and down switch...the "up" position goes to "Direction". What the ferk is that?

And do I need a 3 way toggle switch for that?

What does "CV" go to?

Is the 2M2 pot really nessesary?

[oldrocker]

The up / down switch can be a DPDT which I believe only controls the wah filter. 
The 2 CV connections I believe just connect together.  And the 2M2K pot controls the resonance of only the sample and hold section and doesn't do much if anything to the wah filter.  I built one of these but I'm not totally sure I'm right about all I wrote but if someone else chimes in they may have more accurate information.

[DanielWong]

Well, what does it do?
And do I need a on (on) off style switch?

What does CV mean? Why doesn't it just put both "connections" together instead of confusing the simple minded with CV symbols??

And I was wondering if I could just use a 2 meg pot instead of a 2m2 pot

[calculating_infinity]

Hey Daniel,
     CV means control voltage.  2M pot should be fine.  I can't help you with your other questions though. 

-Jonathan

[oldrocker]

CV does mean control voltage.   I don't know why but usually you would put a 1/4" jack so you could add a voltage controller to it.  The PCB layout looks to me that the two CV's are connected together.  I'm not sure why that is.

[jrc4558]

The switch is for the direction of the sweep of the filter, bro!

[Andre]

Both CV "connections" are normally connected to the 3rd CV connection which is the collector of transistor Q3, but as oldrocker already said, you could also wire them to a switched 1/4" jack, so you could use an external Control Voltage to drive the filter.

And do I need a on (on) off style switch?

No, just plain DPDT for both the switches.

André

[oldrocker]

Right.  That's correct there are 3 CV connections.  The two from the OTA chip from pin 1 and 16 have a 22K resistor before connecting to the collector of Q3.