From Kenny Balys Sent Mon, Jul 16th 2018, 05:44
From Kenny Balys Sent Mon, Jul 16th 2018, 05:44
I have build 17 replacement 50K sliders for the 17 on my Jupiter 4 and replaced them all. There were 2 issues that I had to overcome. First Issue: Major -=-=-=-=-=-=-=--=- - the outer pins of the Roland 50K sliders are connected. These self made stacked ones are not; they make the 2 connections on the bottom and 1 on the top. The upper most is N/C. This is totally fine for 16 of the positions but the VCO LFO MOD slider is connected via the top, not bottom. This problem drove me nuts for hours! When I found it, it was so obvious. (upper means the up direction when facing the opened JP4, looking at the back of the slider boards) Solution: jumper the top pin to the bottom pin Second Issue: Minor -=-=-=-=-=-=-=-=- - the stacking of the potentiometer is meant to level the shoulders of the knob shaft with the originals, this is great as visually, from the outside, the slider caps are all level. The problem is that it is near impossible to get the exact 2.53 mm spacing between boards as solder tends to fatten the pins and push the spacers out a little bit. Also, the tolerances are such that the sliders sit a little bit higher than they should and bash metal. It needs a tiny bit of a spacer to avoid banana'ing the boards when they are fastened again. Solution: I used self adhesive cork about 1.5mm thick along the entire fastening rail. This gives the amount of lift needed. I am too tired now but I will put this all together with photos and descriptions so that everyone may perform this procedure that needs to. My JP4 works so perfectly now, it was all worth it. Every little nuance can be explored again. Perhaps I am the first one to go and replace all 17 50k sliders? Will post back a link on Tuesday with the full description. Cheers! ps: On 14.07.18 16:30 , Lorne Hammond wrote: > agreed following this with much interest, our local music community includes > at least 4 jp-4s. I've joked about us creating a Jupiter 12 or 16 by slaving > them live. > > Lorne > > *From:*Tomislav Babic [mailto:xxxxxxxx.xxxxx@xxxxx.xxx] *Sent:* July-14-18 > 4:39 AM *To:* analogue <xxxxxxxx@xxxxxxxxx.xxx> *Subject:* Re: [AH] Jupiter-4 > 50K Sliders :: 17 are built > > great work. > > Lazslo (maker of Io) built a few of those for my jup4 when he was servicing > it a few years back. > > somebody should start making them in bigger series for sale possibly. > > On Sat, Jul 14, 2018 at 9:30 AM, Kenny Balys <xxxxx@xxxxxxxx.xxx > <mailto:xxxxx@xxxxxxxx.xxx>> wrote: > > > > Correction: attempted build of 18 > > I homer simpson'd the first one. > > The remaining 17 are homer free. Good. > > It took me 7 or 8 hours to assemble so I assume someone more skilled could do > it in 2 or 3. Its hard work. > > The new sliders are silky smooth. > > My JP-4 had something sprayed into the entire envelope and filter section. > And then something else perhaps. The sliders on that side have dead zones and > are utterly ruined. > > At least the (thus far) irreplaceable Arp Rate, Delay Time and center > detented LFO Bend were spared. > > These new ones have a 50K throw with around 4% accuracy. Perfect. > > Tomorrow I install them. > > Another link to "homemade polysynth", source of JP4 frankenslider replacement > idea: http://polysynth.tumblr.com/page/9 > > > On 13.07.18 23:36 , Kenny Balys wrote: > > > So I am building new 50K sliders according to the following advice: > > http://polysynth.tumblr.com/post/84043081480/replacing-roland-jupiter-4-slider-potentiometer > > > > > > If this works this will be a replacement for all sliders with the exception > of Arp Rate, Delay Time, LFO Bend. > > Its incredibly finicky hand work. > > I am very hopeful right now as I have 3 sliders now that are absolutely > shot. > > See photo. > > Will report back as this thing progresses. Doing a build of 24 sliders. > > > > > > -- > > --- Tomislav Babic www.babic.com <http://www.babic.com> - studio, mp3, info > xxxxxxxx.xxxxx@xxxxx.xxx <mailto:xxxxxxxx.xxxxx@xxxxx.xxx> > > www.myspace.com/nimbusdei <http://www.myspace.com/nimbusdei> >