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

[cheater00 .]

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?
>>>
>>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at dropmix.xs4all.nl
>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
>
>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at dropmix.xs4all.nl
> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy