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written by: mikemilton

Thanks for the interesting (as usual) reply. Yes, that is clear.

written by: mikemilton

Mon, 7 Mar 2011 16:37:03 +0000 GMT

So, I'm happily using both a yamaha and a moog passive pedal with the basestation pro.

My (dumb) question is: Does this imply that the base station provides voltage on the ring of a TRS cable? More importantly, does this mean that one could use a CV on these inputs? (like the outputs from a LFO or the moog MP201?). Part of the question is about any risk from inserting a TR plug (shorting the ring) and the other is about voltage and polarity.


written by: john

Mon, 7 Mar 2011 17:08:49 +0000 GMT

Hi Mike

The pedal inputs on the basestation pro work by sending a tone (can't remember, I think it's around 400Hz) out of one side (either the output jack for volume pedals or the ring if using an FC3 type stereo lead), then measuring the level of the tone that comes back using a rectifier/filter/converter circuit. It was quite fiddly to get right and seems excessive upon first glance, but there are good reasons for it. . The first thing is that an audio level AC signal is very unlikely to cause harm if accidentally wrongly connected. We didn't want to have a DC level that could blow things up or create huge thumps if plugged into a mixing desk. The second and probably more important reason is that many volume and expression pedals use cheaper carbon potentiometers rather than conductive plastic. Conductive plastic pots take a DC level well, and are used for most high quality controller type (rather than audio) faders as a result. Carbon pots don't, they degrade very badly over time when DC is left across them, so we used and AC measurement technique to avoid the possibility of this. This also has the useful side effect of making the system work with ac as well as dc coupled volume pedals.

I hope that makes things clearer..


written by: mikemilton

Mon, 7 Mar 2011 17:46:54 +0000 GMT

Thanks for the interesting (as usual) reply. Yes, that is clear.

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