Any Roland JX-8P users on Gearslutz?

[onemoretime]

Mine is all broken and has dead voice chips. It sounds a bit harsh but I guess I could get some good sounds if I can fix it.

[djmukilteo]

Have you tried the Roland Clan forum?

[onemoretime]

I tried but that board is not very active...
Any help will be appreciated! Thanks

[danielb]

Hi,

Try this mailing list:

rolandjxanalogs : Roland JX Series Analog Synths

D.

[golden beers]

are you sure it's a dead chip?
there's a ton of faults that will knock out a voice

[analogbass]

Exactly. Instead of wasting time trying to figure out what could be any number of things, spring for a little ca$h and a tech will deal with it. Those japanese synths are for the most part indestructible once working well, if properly cared for.

Nice synth, well-regarded back in the day and still very good if often overlooked these days.

[Diametro]

Originally Posted by djmukilteo

Have you tried the Roland Clan forum?

It's not about Roland VINTAGE synths ... Basically, it's for the newer models (Fan-G/X and V-Synths) ...

[djmukilteo]

Originally Posted by Diametro

It's not about Roland VINTAGE synths ... Basically, it's for the newer models (Fan-G/X and V-Synths) ...

Yea well I just thought maybe there would be someone on there that might have help because nobody here does!

[idiotboy]

This seems like something Don Solaris might be able to help with. Or maybe Gilwe on thew KSS site.

Longshots, but, still.

Good luck!

[djmukilteo]

For parts you can check

VINTAGE PLANET - Parts Service for Vintage Synthesizer Repair

[onemoretime]

Please guys all I need to know is how to get the synth to display the voice chip that is making the sound so I can sort out which one is the faulty one causing the issues and the name for the voice chip IC so I can order it online.
I fixed a juno 106 before. All I had to do is get it to display the number and figure out its number three order a replacement from analoguerenaissance and solder it in. Easy.
No need to have a tech working to the tune of $75 an hour on a 1985 synth that is worth $200 in the ebay market place.
I mean if it was a jupiter 8 or a minimoog or something very expensive like that spending a few hundred to send it in for repair would make much more sense right?
But I like this synthi a lot and I bet you if it had knobs and sliders alll over it would demand a much higher price in the ebay marketplace
I am sure it has to be the voice chip because there are dead keys in poly mode but when I put it in solo the dead keys suddenly make sound and no more missing notes. However I would like to do chords with it and pads as well so I really have to get this fixed. Any help will be appreciated. Thanks.

[djmukilteo]

Do you have the schematic and a scope?
I would think it would be fairly easy to locate the outputs and check them....
any other way would just be guessing!

[golden beers]

Originally Posted by onemoretime

I am sure it has to be the voice chip because there are dead keys in poly mode but when I put it in solo the dead keys suddenly make sound and no more missing notes. However I would like to do chords with it and pads as well so I really have to get this fixed. Any help will be appreciated. Thanks.

a voice with no output does not mean it is a dead chip. like i said it could be any number of faults.

i had this exact same problem with my Pro5, turned out to be a bad solder joint on the volume output of one of the voices.

[rasmus]

i´m no synthtech and have no experience with the jx8p...
but did you try this: after power on press a key and count at which number the dead voice appears, power off/on again and repeat it, same number?
check several times...
if it´s the same number over an over again, then it might work like on an esq-1 with the filter chips.
now you got to check which chip it is, swap the suspected chip with another one, repeat above procedure, does the number of the deadvoice change?
if it does, you got it narrowed down to 2 chips, keep on swapping till you got the bad one
if it doesn´t try other candidates...

keep in mind im no expert, this is at best a sophisticated guess how to solve the problem

good luck!

hannes

[Novosibirsk]

On a slightly different 8p topic, I was wondering if anyone has any solutions for deteriorating membrane buttons. The ones on my jx-8p look mint, but they require more than a couple really firm pushes to get them activated.

[kpatz]

You can download the service manual from here: http://manuals.fdiskc.com/flat/Rolan...e%20Manual.pdf

There is a way to get it to "display" which voice is playing but the pdf is taking a while to download so I won't be able to tell right away... heading out. (EDIT: Press the PIANO 2 and 3 tone buttons while turning the JX-8P on to enter test mode. The voice being played is indicated by the Solo, Unison, Poly, Volume, Brilliance, and Vibrato LEDs corresponding to voices A, B, C, D, E, F respectively.)

As for the membrane buttons, they are actually tactile switches beneath the membrane. You would have to take the panel apart and replace the failing buttons.

[onemoretime]

Originally Posted by kpatz

You can download the service manual from here: http://manuals.fdiskc.com/flat/Rolan...e%20Manual.pdf

There is a way to get it to "display" which voice is playing but the pdf is taking a while to download so I won't be able to tell right away... heading out. (EDIT: Press the PIANO 2 and 3 tone buttons while turning the JX-8P on to enter test mode. The voice being played is indicated by the Solo, Unison, Poly, Volume, Brilliance, and Vibrato LEDs corresponding to voices A, B, C, D, E, F respectively.)

As for the membrane buttons, they are actually tactile switches beneath the membrane. You would have to take the panel apart and replace the failing buttons.

First off let me take the chance to thank you for linking this!thumbsup
You are right. I now know that the offending chips are chip no 4 and chip no 6. Does anybody know what is the name of the chip used in the jx-8p maybe I can order 2 replacement chips online and fix this.
Thanks again everybody for your help!

[kazper]

From the posted print set...

VCA and VCF are IC59 =IR3R05

make sure you look at the notes based on the Serial number because the schematics are slightly changed on newer models.

I'm sure your going to have a hard time finding these IC's:

VINTAGE PLANET - Parts Service for Vintage Synthesizer Repair - Transistors


more info:

SUPER JX-10 & MKS-70 SYNTHESIZER INFORMATION

Finally some really good sources of manuals/Service Manuals
Analog Hell : studio - analoghell.com

[Catabolic]

Originally Posted by danielb

Hi,

Try this mailing list:

rolandjxanalogs : Roland JX Series Analog Synths

D.

Does anyone belong to this group? I tried to join this group as I purchased an MKS-70, but my request has been in limbo for a week or two. The group seems to still have active posts, but perhaps the moderator is on vacation?

[Teknobeam]

Originally Posted by analogbass

Exactly. Instead of wasting time trying to figure out what could be any number of things, spring for a little ca$h and a tech will deal with it. Those japanese synths are for the most part indestructible once working well, if properly cared for.

Nice synth, well-regarded back in the day and still very good if often overlooked these days.

Absolutely.

[dougt]

I have the voice chips if you still need them. The JX-8P is definitely still a bargain at current prices. JX-3P as well. The dual osc design is more interesting than single DCO like the Junos.

[Pro5]

Originally Posted by dougt

I have the voice chips if you still need them. The JX-8P is definitely still a bargain at current prices. JX-3P as well. The dual osc design is more interesting than single DCO like the Junos.

This man speaks sense. The JX-3P especially is an under-rated gem right now. Get one while they are still cheap.

[Teknobeam]

The JX8P is probably the most under valued analog synth out there at the moment. Interestingly, I think many of the people that are selling them haven't discovered what they can do. probably just dabbled around with the factory presets, possibly modifying a few of them. That instrument goes way beyond that. That's all i will say.

[Pro5]

Originally Posted by Teknobeam

The JX8P is probably the most under valued analog synth out there at the moment. Interestingly, I think many of the people that are selling them haven't discovered what they can do. probably just dabbled around with the factory presets, possibly modifying a few of them. That instrument goes way beyond that. That's all i will say.

tutt

had mine for a few years - only used custom sounds and had it hooked up to a BCR. It can do LOTS of many many varied sounds (not just pads) the problem is the more interesting sounds can be done (and then some) in digital/software as the filters are really quite poor sounding (weak). As an overall synth is a bargain, it has some great pads capability and (on mine at least) nice key action/aftertouch (when cleaned). even so it's actual sound engine was the least inspiring of the ones I kept (polysix, 3P SY77 etc) so it had to go - I'd have kept it if I didn't want less clutter

The reason I said the 3P is an even better deal right now is because it really does have a much better filter than the 8P, ok only one ENV but it sounds way more alive - 8P can sometimes sound canned/fake in comparison - but hey I only run them side by side for nearly 3 years so what do I know

oh and I used the 8p VERY little in my actual music but always found it nice to play slow pads (or even piano hooked up to a better piano sound module etc) - it's got a very 'general synth' tone to it that I've heard in a million places, and the 8Pvst comes very close (as does the Arturia minimoog in pad mode but that does stuff the 8p can't touch) conversely the 3P is probably my most used synth in actual recorded music I've done.. always inspiring.

[Teknobeam]

Originally Posted by Pro5

tutt

had mine for a few years - only used custom sounds and had it hooked up to a BCR. It can do LOTS of many many varied sounds (not just pads) the problem is the more interesting sounds can be done (and then some) in digital/software as the filters are really quite poor sounding (weak). As an overall synth is a bargain, it has some great pads capability and (on mine at least) nice key action/aftertouch (when cleaned). even so it's actual sound engine was the least inspiring of the ones I kept (polysix, 3P SY77 etc) so it had to go - I'd have kept it if I didn't want less clutter

The reason I said the 3P is an even better deal right now is because it really does have a much better filter than the 8P, ok only one ENV but it sounds way more alive - 8P can sometimes sound canned/fake in comparison - but hey I only run them side by side for nearly 3 years so what do I know

oh and I used the 8p VERY little in my actual music but always found it nice to play slow pads (or even piano hooked up to a better piano sound module etc) - it's got a very 'general synth' tone to it that I've heard in a million places, and the 8Pvst comes very close (as does the Arturia minimoog in pad mode but that does stuff the 8p can't touch) conversely the 3P is probably my most used synth in actual recorded music I've done.. always inspiring.

I have to disagree. I'm in the middle of putting my new studio together right now as part of a whole house renovation. It's taking longer than expected and in one room I have a G5 MAC with a small audio system , in another room i have two keyboard stands set up with all of my vintage hardware keyboards. So, what I have been doing while things are in limbo is spending time with each synth off and on with the goal of making new sounds. I don't even have amixer connected, so I have to repatch the audio to the synth I am working with each time. This has been beneficial in that it has kind of forced me to concentrate on one synth at a time in depth. The JX8P has really delivered sounds that i never would have expected. It's filter is amazing if you get to it properly. For years I used the JX8P as a pad machine mostly with the chorus engaged. When I get things back on track I will definitely post some sounds that i have achieved with it. I think you will be surprised.

[Pro5]

Hey i really like the 8P i'm not saying different. I'm just saying that in my case (and probably other's) we didn't sell it ONLY because we only ever used presets! I've also got stashes of great custom sounds + some found on the net that a really great, but my point remains that many of those sounds I found do-able across a combination of my SY77 (powerhouse) and VSTs - due in part to the very digital nature of the 8Ps filter. It has zero ballz in the resonance even though it's a very versatile synth, it's just not a hard hitter or a fast player like many older synths are.

But it sure had some great sounds yes. One patch I programmed had a slow evolving filter that lasted seems like a minute! (ok was more like 30 seconds) and it was this beautiful string sound that welled up and died down with little aftershocks - sound quite jupiter 8 ish in some respects but in the end it was first to go when I compared basic sounds between that and my polysix and jx-3p. If i wanted to keep more synths then yeah I'd have kept it cos they don't sell for much.

3P sounds similar in some ways but completely different in a tonal capacity, it simply sounds way more alive than the 8P - more analog! - the 8P sounds like VERY warm digital (when I had the D-50 I could compare them and often preferred the D-50 for certain things which was also a warm synth for digital) - the 8P has this very epic/classy tone esp in the lower octaves - can sound very electric and deep (and no I didn't use that horrible chorus on everything - another thing where the 3P sounds nicer imo - it may have the same chorus chips I'm not sure but when it's layered on top of an IR3109 vs an IR3105 filter it sounds very very nice. And the basic tone of the 3P when you hit the sweet spot - it makes you go 'wow' - again almost jupiter 8 ish in some regards). 8P never 'wowed' me it was always just a 'nice sounding synth' and I used to play it's sounds for my pleasure rather than for making songs with!

Both synths overlap and yet remain tonallly distinct partly why I wanted rid of one of them, the 8P is the 'super synth' of the pair with all those bells n whistles, screen, velo, at, cart, 2nd env etc and yet I still kept the 3P over it because in a song the 3P imparts personality and edge, where the 8P just kinda sat in the back basically doing sounds that had been overused a fair bit in the mid 80s (if you stick to pads) something in it's sound... and when i went to leads or rhythmic stuff it could sound fairly nice, but wasn't stunning for that! 3P cut through pleasently and adds a shine to other synths (layers great with FM) but 8P was either all in the back sounding like the cure or all in the front sounding late 80s 'synth effects'. I owned it for 3+ years and it was the synth I used most as a controller board - I compared it to Ajuno (and i'm not juno fan even though I've had 4 of them inc 3 ajs) but the AJs vivid punch and sheen made the 8P sound slow and dated in some regards.

Track down some custom patches on the net with patch names like 'airship' IIRC, they sounded great and I enjoyed noodling but again - found it hard to get them into MY music and ultimately had these other edgier/more unique sounding synths (P6, 3P and AFM in the '77) to replace it with.

Also the FREE VST is 90% there - I A/Bd it before getting rid of the hardware and you could tell the VST was a tad more plastic in the filter and not quite as 'warm' but aside from that it sounded like an 8P - esp in a mix - and when hardware can be so easily replicated in VST it's the first to go for me, and considering it was my least used for it's own sounds... etc

What it is though is a very decent sound board that can give many varieties of 'ok' sounds and some stunning pads, bass is not it's strong point and it's filter isn't anywhere near as gorgeous as the IR3109. It's basically as digital sounding as analog (DCO) has ever sounded in my opinion - and for that there are warm/old digitals out there than can run rings around it (D-50, SY77 to name 2)