jp6/jp8

[J.D.McEachin]

At 11:05 AM 4/24/99 PDT, Paul Nugteren van wrote:

>I think the software generated envs on the jp6 were cheaper too. 

Hard to say - it required 3 CPUs instead of one.

>14bit quantization you say hmmm that's a lot better than 7bits. 

Reread my other post on the difference in resolution on ADCs and DACs
that is typical in digitally controlled analogue synths.

I should have mentioned that the JP6 DACs were also 14bit.  The
difference here is that at the time the JP8 came out, 14bit was pushing 
DAC technology (this was pre-CD), and thus too expensive to use, so they
went with a 12bit DAC.  When the price on 14bitters dropped, they switched.
The price dropped even more by the time the JP6 came out.  Other component
prices were dropping too, such as CPUs, SRAMs, and EPROMs.

>Is it very hard to dig into those analog monster like the jp8? I guess 
>everything is pretty much cramped together, so that should be quite 
>difficult to change something or? I'm really wondering how much effort 
>and time it will take to reroute the panel CVs to the CVins of the 
>circuitry and still be able to switch between the adc and direct CV. 

More effort than it's worth.  What parameters do you really need more than
127 levels on, anyway?  If the stepping is bugging you so much, why
don't you just add some caps to smooth out the level changes?

For VCO & VCF, you can either use the bender that's already there, or add
pots & sum them wherever it is the bender gets summed w/ the VCO & VCF CVs.
The bender CV is not routed thru the AD/DA chain on either the JP6 or JP8.

Better yet, just plug a CV pedal in the VCO or VCF jack in the back.  Do
you own either of these synths?  If so, you should learn more about what
you already have.

>Or at least change the adc to 16bits. All those digital parts are 
>ridiculously cheap now, some 1mb sim into it maybe a different 
>microcontroller/chip in it some programming and done, but it wouldn't 
>be all analogue like the first option. 

Writing a synth OS isn't a one person job.  And it is a job, one that
will take a LOT more time than you'd think.  Be prepared to give up
several years of your free time.

>I had in mind just to own an poly an. synth and a small to medium 
>modular. Going digital is still to early, the industry should first 
>get that damn parameter input on those VA synths better, 7bits is way 
>too small.

Why don't you buy a CS50, 60, or 80, and after a few months of playing
with it, ask yourself if it's really such a big deal.  The vast majority
of synth owners have been happy w/ 7bits of parameter info for the last
20 years.

JDM