[sdiy] OT - looking for roland JX10 chorus details

[Bob Weigel]

On 4/21/2012 7:08 AM, Mike Gorman wrote:
> Hi Dave,
>
> I've just had a quick look on the Synfo site, here:
>
> http://www.synfo.nl/
>
> and found a copy of the Service Manual for the JX10. It does appear to use 2
> off MN3009 in the phaser section (though unfortunately, that part of the
> circuit diagram is missing from the scan).
>
> Hope this helps.
>
> Regards
>
> Mike
>
> -----Original Message-----
> From: synth-diy-bounces at dropmix.xs4all.nl
> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Dave Kendall
> Sent: 21 April 2012 11:48
> To: synthdiy diy
> Subject: [sdiy] OT - looking for roland JX10 chorus details
>
> Hi All.
>
> Apologies for the  slightly OT nature. For a particular project I'm breaking
> down some JX10 patches, and porting them over to a Kurzweil K2661, where
> they're being re-programmed using internal synth parameters and onboard FX.
> 99% of the synth architecture can be replicated satisfactorily, but the two
> chorus units in the JX are a big part of the sound, and are proving elusive
> to emulate. I'm not using samples, as they are static, and would be a vast
> memory hog to even approach an accurate reproduction of the cyclic behaviour
> of some of the patches.
>
> Does anyone have a source of info on the chorus circuits used in the JX10? I
> believe the design is a two-BBD thing, *possibly* similar to the BBD board
> of the JH subtle chorus, but I'm not sure about this.
>
> I'm looking for clues as to mod depth, delay, LFO shape and rate - that sort
> of thing. If there is any EQ in there (a la Dimension D) it would be good to
> know too. I've got some way along the road, but any details would really
> help.
> FWIW, the JX10 appears to be two JX8P main boards shoved in a long box with
> a keyboard. It's rather cramped in there....
>
> A schematic would be really fab :-)
>
> cheers,
> Dave
>
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>    
Schematics for everything available are listed on my pages

http://sounddoctorin.com/synthtec/roland/jx10.htm

Seems to have them.  I have a hard copy too here if that doesn't do it.  
The MKS-70 has the same circuit  except in the ROM as I recall on those 
and of course aftertouch sensing /keyboard scanning -Bob

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