The JP8 from Hades

The Roland Jupiter-8 Analogue Synthesizer
Posts: 10
Joined: Mon Feb 15, 2010 2:32 pm
Location: Dublin, Ireland

The JP8 from Hades

Postby synthnerdireland » Fri Apr 09, 2010 12:26 am

As a long term project, although I never thought it would be so, I have in for repair an Ebay special, a JP8 bought from Taiwan as in good cosmetic condition about a year and a quarter ago. I have it about 8 months myself.
It is in good cosmetic condition, but as I got it none of it actually works.
I have rebuilt it as far as being a Jupiter 4 (with 2 Osc's per voice) so far but I have never ever worked on a synth with such a variety of faults on every board.
My logical assumption is that all the parts for this machine came from a Roland service department which was either closed down or just selling off its dead stuff for parts.
Getting the synth as far as a 4 voice tells me that I am about 75% there,the Blog of the work done and the trials and tribulations so far if expressed in a post could be longer than the Lord of the Rings trilogy.
By the way, I might need up to 2 I3R01 envelope chips if anyone can spare any, and on the other hand I am in a position to fix any ModCon or Mod boards in Europe while I have my whole test system together.
This is only my second post to this group,
All the best,

Posts: 22
Joined: Fri Feb 06, 2009 1:41 pm
Location: Dublin, Ireland

Postby patrickwalsh » Mon Apr 19, 2010 4:03 pm


2x IR3RO1 envelope generator chips are on the way

Posts: 10
Joined: Mon Feb 15, 2010 2:32 pm
Location: Dublin, Ireland

JP8 Hell

Postby synthnerdireland » Wed May 12, 2010 12:35 am

It's now a Jupiter 6, and I now have a spare ModCon board.
All 16 Oscillators now tune and I am close to Jupiter 8's ville with the replacement of a couple of envelope chips (I3R01)
All the best.

Posts: 10
Joined: Mon Feb 15, 2010 2:32 pm
Location: Dublin, Ireland

Postby synthnerdireland » Thu Mar 03, 2011 12:29 am

The Jupe from Hades is finished.
Following the final Envelope chips arrival, 3 days of recalibration, and the installation of Encore MIDI, she is finished.
The only fly in the ointment during the final phase was the output level selection switch on the rear panel, (0dB or -20dB). The jack outputs were all intermittent while the XLR outs were fine. I had to remove the switch and clean 30 years of Silver Sulphide from the contacts (they were black).
After all this I thought the synth was fine, and left it up to the customer to let me know of any issues.
The customer is a member of this list, and there are a couple of issues, resolving them might lead to some interesting posts and facts emerging.
For the most part, I am happy to have put this one to bed.

Posts: 189
Joined: Tue Nov 06, 2007 1:41 pm

Postby noidear » Thu Mar 03, 2011 11:58 am

Sounds like you have the patience of a saint, but congrats for finishing it. I remember restoring one of mine last year. Luckily all the electronics were fine, just rusty panels and a lot of dirt and grime, so I took the whole thing apart and cleaned it all up. It took about 3 months to get it all done but now it looks like new.

Hope the customer has fun playing it.

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