Any Roland JX-8P users on Gearslutz?

onemoretime · 28th December 2009, 07:54 AM

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 · 28th December 2009, 08:08 AM

Have you tried the Roland Clan forum?

onemoretime · 28th December 2009, 08:25 AM

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

danielb · 28th December 2009, 09:32 AM

Hi,

Try this mailing list:

rolandjxanalogs : Roland JX Series Analog Synths

D.

golden beers · 28th December 2009, 11:41 AM

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

analogbass · 28th December 2009, 05:28 PM

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 · 28th December 2009, 05:32 PM

Quote:

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 · 28th December 2009, 05:34 PM

Quote:

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 · 28th December 2009, 06:08 PM

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 · 28th December 2009, 06:09 PM

For parts you can check

VINTAGE PLANET - Parts Service for Vintage Synthesizer Repair

onemoretime · 28th December 2009, 08:41 PM

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 · 28th December 2009, 08:46 PM

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 · 28th December 2009, 10:27 PM

Quote:

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 · 29th December 2009, 02:21 AM

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 · 29th December 2009, 03:23 AM

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 · 30th December 2009, 12:19 AM

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 · 30th December 2009, 03:39 AM

Quote:

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!

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 · 30th December 2009, 04:54 AM

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

28th December 2009, 07:54 AM	#1
onemoretime Gear maniac Join Date: Dec 2009 Posts: 210	Any Roland JX-8P users on Gearslutz? 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.

28th December 2009, 09:32 AM	#4
danielb Gear addict Join Date: Mar 2009 Posts: 319	Hi, Try this mailing list: rolandjxanalogs : Roland JX Series Analog Synths D. __________________ Listen to my music at http://alonetone.com/danielb

28th December 2009, 11:41 AM	#5
golden beers Lives for gear Join Date: Dec 2008 Posts: 3,182	are you sure it's a dead chip? there's a ton of faults that will knock out a voice __________________ bbow73: The brrrap-a-bap says it but don't tell me it depends on the bogillator of the said snap-bap.

30th December 2009, 12:19 AM	#16
kpatz Gear addict Join Date: Mar 2009 Location: NH Posts: 331	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. __________________ There's nothing better on a cold winter evening than to tweak the knobs on a nice warm analog synth. Yamaha Motif XS6 ~ Alesis A6 Andromeda ~ Roland D-550 ~ Yamaha TX802 ~ OP-X ~ FM8 He did use the OBXa on Jump but I believe 1984 was a Roland JX3P. - posted on Youtube

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28th December 2009, 08:08 AM	#2
djmukilteo Lives for gear Join Date: Aug 2009 Posts: 559	Have you tried the Roland Clan forum?

28th December 2009, 08:25 AM	#3
onemoretime Gear maniac Join Date: Dec 2009 Posts: 210	I tried but that board is not very active... Any help will be appreciated! Thanks

28th December 2009, 05:28 PM	#6
analogbass Lives for gear Join Date: Dec 2006 Location: Phoenix Posts: 769	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.

28th December 2009, 06:08 PM	#9
idiotboy Gear maniac Join Date: Jul 2007 Posts: 196	This seems like something Don Solaris might be able to help with. Or maybe Gilwe on thew KSS site. Longshots, but, still. Good luck!

28th December 2009, 06:09 PM	#10
djmukilteo Lives for gear Join Date: Aug 2009 Posts: 559	For parts you can check VINTAGE PLANET - Parts Service for Vintage Synthesizer Repair

28th December 2009, 08:41 PM	#11
onemoretime Gear maniac Join Date: Dec 2009 Posts: 210	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.

28th December 2009, 08:46 PM	#12
djmukilteo Lives for gear Join Date: Aug 2009 Posts: 559	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!

29th December 2009, 02:21 AM	#14
rasmus Gear maniac Join Date: Mar 2005 Location: Hamburg/Germany Posts: 275	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

29th December 2009, 03:23 AM	#15
Novosibirsk Gear nut Join Date: Aug 2009 Posts: 107	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.

30th December 2009, 04:54 AM	#18
kazper Lives for gear Join Date: Jan 2007 Location: Seattle WA Suburbs Posts: 516	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

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