[sdiy] help finding roland filter schematics?

[Louis van Dompselaar]

Can the SH-3A possibly be earlier than the SH-3?
Then the swap would make sense.



> Thank you for the hint. This seems to be wrong indeed. The  
> servicemanual, where it is taken from says clearly "SH3" on its  
> frontpage - I always overlooked that and took for an SH3A manual.
>
> If this diode ladder filter is an SH3, all the rumours on patent  
> infringements in the SH3 (which shall have caused the change to  
> SH3A) would be false. Now: why did roland change the filter design?
>
> Florian
>
>> What I find interesting in the link below is that it lists the  
>> SH-3A filter as
>> a diode ladder (and even includes a schematic for that), when the  
>> SH-3A actually
>> has a transistor ladder.  It's clearly a traditional Moog  
>> transistor ladder in
>> the Service Notes, which I have verified against the actual SH-3A I  
>> have here.
>> And the Service Notes list the transistor ladder in all revisions,  
>> so Roland aren't
>> hiding it in any way.  Not sure where the diode-ladder versions  
>> comes from, but
>> I'm sure it's not the SH-3A.
>