[sdiy] Fwd: Analog matrix chip in Boss ES-8 pedal switcher

[Mikko Helin]

ES-8 is an overkill tool for just the switching purpose, yet it can't
program other than MIDI pedals. It would be also cool to have some DSP
FX integrated into the looper, like some digital delay/reverb FX. Also
it would be nice if there were a standard for storing patches as
analog audio chirps (using FSK for an example) so that no MIDI would
be needed at all. Don't know if the TC TonePrint/ToneTransfer (via
guitar's pickup) is open sourced or not but a protocol like that would
be nice. There should still be some kind of handshaking between
devices for storing/loading patches like some DC level shift or change
in resistance (between input and GND for an example) so that the FSK
chirps could be prevented going to speakers.

On Mon, Jan 25, 2016 at 3:50 AM, cheater00 . <cheater00 at gmail.com> wrote:
> Even if it's the AD8113, do you guys think the specified crosstalk of
> -83 dB is adequate if the signal with crosstalk is then going into an
> overdrive pedal?
>
> On Mon, Jan 25, 2016 at 1:25 AM,  <eidorian at aladan.net> wrote:
>> How about the coolio 8x16 Zarlink MT8816?  Just throwing part number
>> suggestions around, no actual basis for thinking it might be that chip :)
>>
>> Cheers,
>> A.
>>
>>
>>
>>
>> On 2016-01-25 10:43, rsdio at audiobanshee.com wrote:
>>>
>>> It's very likely that the ES-8 does not handle all switching in a single
>>> chip.
>>>
>>> First of all, IN 1 and IN 2 cannot both be active at the same time.
>>> The diagram shows a simple 2-to-1 switch that is independent of the
>>> matrix.
>>>
>>> The AD8113 has a 60 MHz bandwidth - it's probably way too expensive
>>> and overqualified for guitar pedal switching, although the $700 ES-8
>>> might be able to get away with it. Internally, it's implemented as 16
>>> separate 16-to-1 multiplexor switches, and it would probably be
>>> cheaper to just use 16 separate chips if you don't need the 60 MHz
>>> bandwidth.
>>>
>>> The ES-8 also has 2 mono mixer units that can alternately be used as
>>> 1 stereo mixer unit. These mixer inputs and outputs must also be part
>>> of the matrix.
>>>
>>> They probably dedicate a cheaper, audio bandwidth (not video
>>> bandwidth), 12-to-1 analog mux for each output (9 sends, 2 mixer
>>> inputs, out 1 left & out 1 right). I count only 11 inputs for each
>>> destination. Standard 16-to-1 mux chips cost less than two 8-to1 mux
>>> chips, so they might even waste inputs.
>>>
>>> Don't forget that the switching could be handled by reed switches or
>>> individual FET parts instead of an analog multiplexor chip.
>>>
>>> Brian
>>>
>>>
>>> On Jan 24, 2016, at 3:49 PM, Tom Wiltshire <tom at electricdruid.net> wrote:
>>>>
>>>> Ok, so that rules out a load of the smaller ones instead then. AD don't
>>>> seem to make a 12x12 matrix, so it'd have to be a 16x16, something like
>>>> AD8113. But that seems unlikely because I can't see a commercial product
>>>> paying for more switch than they need. Perhaps a different manufacturer? Who
>>>> makes a 12x12?
>>>>
>>>> On 24 Jan 2016, at 22:40, Mikko Helin <maohelin at gmail.com> wrote:
>>>>
>>>>> ES-8 has two inputs (and outputs), seven mono sends (and returns), one
>>>>> stereo send (and return) plus single mono (volume) mono send and
>>>>> return. For that you need at least 12x12 matrix.
>>>>>
>>>>> On Mon, Jan 25, 2016 at 12:08 AM, Tom Wiltshire <tom at electricdruid.net>
>>>>> wrote:
>>>>>>
>>>>>>
>>>>>> There's a lot of possibilities…maybe one of these?:
>>>>>>
>>>>>> http://www.analog.com/en/products/switches-multiplexers.html
>>>>>>
>>>>>> It's only 8 loops, so that probably rules out the biggest 16x16 chips.
>>>>>>
>>>>>> On 24 Jan 2016, at 19:31, "cheater00 ." <cheater00 at gmail.com> wrote:
>>>>>>
>>>>>>> Hey guys,
>>>>>>> anyone know what chip they might be using here?
>>>>>>>
>>>>>>> http://www.bossus.com/products/es-8/
>>>>>>>
>>>>>>> What's your guess on the crosstalk between two adjacent channels? -40
>>>>>>> dB?
>>>>
>>>>
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>>
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