[sdiy] 8x8 switching matrix

Derek Holzer derek at umatic.nl
Tue Jul 14 11:07:51 CEST 2009

Another question about the MT8808, actually it's a couple of questions 
but since they both relate to input voltage they are probably the same:

1) "12Vpp analog signal capability": if my system is +/-15v, I know it's 
unlikely that a module will send out a rail-to-rail signal, but how 
could I protect the CMOS just in case it did?

2) The cross-talk is directly related to the peak-to-peak voltage of the 
system. Would people recommend padding/scaling down the input voltage 
before it goes through the IC and then adding gain afterwards to reduce 
the cross-talk (at the expense of added noise and possibly 
distortion/imprecision of the signal)? If so, could anyone point to a 
circuit which demonstrates this (simple op-amp stuff I guess)?


Ullrich Peter wrote:
> I used the MT8816 (8x16 in PLCC44) for my universal midi interface (I use it fort he Poly61) - works fine for digital signal and audio but should also suit for video switching. In one application in our company I used it also for mixing signals - but here you can not use the full matrix circuit due to the resulting schematics.
> Prior to this chip we used the MT8804 chips and the MT8812 (8x12). The MT8812 is used in my Casio SK1 midi interface.
> Ciao
> Peter
> http://Come.to/ullrich
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Derek Holzer
> Sent: Monday, July 13, 2009 12:55 PM
> To: Rainer Buchty
> Cc: Synth DIY
> Subject: Re: [sdiy] 8x8 switching matrix
> Hi Rainer,
> just stumbled across the MT series stuff, probably while you were typing 
> this! Thanks!
> Out of curiosity, is the MT8806A or similar what Buchla uses in the 210e?
> http://www.buchla.com/model_210e.html
> D.
> Rainer Buchty wrote:
>> On Mon, 13 Jul 2009, Derek Holzer wrote:
>>> I know this could be done with a microprocessor and a lot of latching, 
>>> but I wonder if there is some specialty IC out there that could do 8x8 
>>> signal matrix switching?
>> Does the MT8808 suit your needs?
>> Rainer

::: derek holzer ::: http://blog.myspace.com/macumbista ::: 
http://www.vimeo.com/macumbista :::
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