Master Sensitivity Pot?

[Ken Forgettable]

just reduce the gain across the board on all inputs.

Two advantages Dmitri's design has over the all in one - it doesn't need a split ground plane and you can update the analogue board

For the 'ordinary' inputs you could you could modify a Snythex extension board to reduce the gain on all your new EXT inputs, but the problem comes for the 'special' inputs - ie hi-hat and snare.

I'm still surprised that the most frequently used inputs (hi-hat, snare and bass drum) all hang off the first mux'. I briefly wonder if there may be an advantage in spreading these dominant in's between the mux'es for parallel sampling. As this is a zero crossing design (for want of a better term) I doubt that.

Anyway, if pads could be assigned to a different ADC channel you could do all you want on an extension board via the EXT header.

It seems to me your only other option for the dominant in's would require you to cut the track just after R12. Replace R12 with a 4K7 pot and tap the signal from there back into pin40. A reckless undertaking.

[jeffbeckib]

I can't believe I actually understand what you are talking about.... Thanks for your input.
Perhaps theres a way I could split the ribbon off the all-in-one input connector and have just the pins that go to the pads go to a separate board with a master trimpot??? and have the pads all connect on That connector while leaving the special inputs unmodified?

Why do you say the snare is a "special input"? isn't it the same as any of the toms or aux??

just reduce the gain across the board on all inputs.

Two advantages Dmitri's design has over the all in one - it doesn't need a split ground plane and you can update the analogue board

For the 'ordinary' inputs you could you could modify a Snythex extension board to reduce the gain on all your new EXT inputs, but the problem comes for the 'special' inputs - ie hi-hat and snare.

I'm still surprised that the most frequently used inputs (hi-hat, snare and bass drum) all hang off the first mux'. I briefly wonder if there may be an advantage in spreading these dominant in's between the mux'es for parallel sampling. As this is a zero crossing design (for want of a better term) I doubt that.

Anyway, if pads could be assigned to a different ADC channel you could do all you want on an extension board via the EXT header.

It seems to me your only other option for the dominant in's would require you to cut the track just after R12. Replace R12 with a 4K7 pot and tap the signal from there back into pin40. A reckless undertaking.

[jman 31]

You could have a master trimpot if you could find a 30 gang pot! Each input has to be separate from the others, there is no getting around that unless you do what Ken said and that sounds like an undertaking for someone with experience.

[Ken Forgettable]

split the ribbon off the all-in-one input connector and have just the pins that go to the pads go to a separate board with a master trimpot???

To make that work you'd be using a different design entirely - call it a radio!

If you look at R12 on the Synthex PCB schematic it is connected to the *output* of the multiplexer. In other words; the 8 inputs to this chip are rapidly switched on, one at a time, and all can use the single output labelled X on the schematic. Imagine dropping 8 marbles into a funnel - they all drop through but one at a time.

Why do you say the snare is a "special input"? isn't it the same as any of the toms or aux??

Erm, is it???