[sdiy] tired old question: Juno 106

[Cornutt, David K]

From: CCartCat at aol.com [mailto:CCartCat at aol.com]
 
> The 2nd voice drops out intermittantly, works sometimes, coming thru sputter and static as if  
> thru a bad connection.  Some general noise in the 2nd voice when activated, whether the tone  
> comes thru or not.  Sometimes cranking the resonance control to about 75% to 100% will cause  
> the tone to come thru.   
 
[ I really really hate MS Outlook.  I just want everyone to know that...]
 
This sounds like the usual problem with the VCF/VCA IC.  I don't recall the number right
off hand, but it's one of the Roland chips. 

 > FWIW:  Also put filter in self oscilation and turned off the DCOs:  not all voices  
> are at the same pitch in self osc. (OK, that I can live with--just saying for the sake  
> of diagnostics); voice 2 is dead quiet and 4 has maybe the faintest sound coming  
> thru if you listen really carefully. 
 
That's just a calibration problem.  You can find calibration instructions with a Google. 

 >  Have read in my Google travels that certain chip lots (41C and 42B) were bad.   
> But have had this Juno for years generally working (at least to my standards). 
 
Some of them last quite some time before they fail.  I had one in my 106 that lasted
eight years before it finally went.
 
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20040813/20539546/attachment.htm>