Keyboard Shortcuts
ctrl + shift + ? :
Show all keyboard shortcuts
ctrl + g :
Navigate to a group
ctrl + shift + f :
Find
ctrl + / :
Quick actions
esc to dismiss
Likes
- Xpantastic
- Messages
Search
|
M12 all 12 voices fail tuning...can I send anyone my PS board for recapping?
Hi all, I recently picked up an M12 that has tuning probems. All 12 voices fail tuning. I've tried UNTUNE and re-tuning, as well as resetting the software (hold CLEAR on power-up and then YES) to no avail. When I manually turn on all the voices, 1-6 are way out of tune and 7-12 are silent. I'm hoping it's just that the power supply board needs recapping? I recall reading somewhere that global tuning issues are likely traced back to that.
Currently my soldering tools and multimeter are not accessible, so I'm thinking easiest thing to do is just pull out the PS board and send it to be diagnosed and recapped if necessary. Much easier than packing up/shipping the whole synth! Would any of you who have an M12 be willing to perform this work for me? Of course I'd pay for bench time and parts. Or is such action premature? Anyone have suggestions as to other things for me to try? Like specific ICs I should try to reseat? Much thanks, Howie |
|
|
Re: Matrix-12 PSU problem
Hi Karl,
toggle quoted message
Show quoted text
Thanks for the advice, I'll probably open her up someday next week and see if there's any damage or anything out of place. Don't suppose you know where i could find a schematic for the PSU by any chance? I've an Xp service manual handy but would prefere to work off the schematics for the 12 just for proper reference. Thanks again - Dave --- In xpantastic@..., Karl Schmeer <shire03@...> wrote:
|
|
|
Re: Matrix-12 PSU problem
--- On Thu, 4/1/10, David in swords wrote:
|
|
|
Matrix-12 PSU problem
I was wondering if anyone could shed some light here?
recently (within the last month or so ) my M12 has been flicking itself on and off for very short periods of time, thought it was a bit strange but decided to see if the problem persisted,and hey presto,after being powered up earlier today for a while i returned to find it 'off'... the power switch was still on and the light in the switch itself was still lighting,all displays and led's were off tho. after power cycling, my power switch light was still on and again all displays were off. I know that the PSU's can get a bit shaken in the 12's and Xp's after a while, I have my suspicions that the slo-blo fuse may need replacing in the PSU? im kinda hoping that it is the fuse,as it would be a simple job i could do myself. would love to hear your thoughts,or if some1 has has similar experience / success with this. Dave |
|
|
Re: Stuck note / tunings fail
Hi Chase,
toggle quoted message
Show quoted text
Glad everything is okay. And thanks for posting back about the fix. Class act, you are! I will add this to my fail log, in case the same kind of symptoms show up again. (I don't keep track of the names btw, just the problem and the fix.) Best Regards Karl Schmeer --- On Mon, 3/15/10, Chase Smith <plus_321@...> wrote:
From: Chase Smith <plus_321@...> Subject: Re: [xpantastic] Stuck note / tunings fail To: xpantastic@... Date: Monday, March 15, 2010, 8:51 PM ? I'm sorry, but I made a really stupid mistake here.? When I was working on the song, I ran out of channels on my mixer so I plugged into where I would usually have my pc stereo out (channels 23 and 24).? I had never used these channels in this configuration for synths, but I had wired them with XLRs instead of 1/4" so I could use the preamps if I needed them. Well, I either accidentally flipped the switch for phantom power or it was on the whole time and the computer didn't mind.? So the Xpander was freaking out because it was getting something like 46 V at the output which it obviously didn't like.? It's kind of embarrassing to admit this, but I'm just happy that there are not major issues here.? Again, thanks a lot for taking the time to read my emails and help me out. Thanks, Chase Smith From: Karl Schmeer <shire03@sbcglobal. net> To: xpantastic@yahoogro ups.com Sent: Mon, March 15, 2010 2:27:12 AM Subject: Re: [xpantastic] Stuck note / tunings fail ? Hi Chase, ? ? ?strange.? It will tune them, but as soon as a plug in a cable for theAhhh, a good clue, Is the mixer / CV generator plugged into the same power outlet as the Xpander. You could have a ground loop problem. Other possibilities: The mixer could have a problem. But that seems unlikly. A more likly? situation is the cable has a short in it and plugging it in shorts the outputs to ground. What are you plugging into the CV jacks? This pedel or midi/CV device might have a ground problem or overvoltage for that matter. Before plugging the mixer or CV generator in to the Xpander again I would get a Voltmeter and check the tip and ring of the cable. Check for shorts, and continuity to ground.? This could be a loose ground connection inside the Xpander. All the problems (now) seem to revolve around the potentiometer display board. Now reseat the chips and check cables on that board. Also look closly at where the jacks are soldered into the circuit board. A loose solder connection here could also cause the symptoms you describe. If you have a soldering Iron, you could reflow the solder on all the output and CV jacks.? ? Also, maybe worthy of note is that whenever I turn it on and it doesn't >tune, I can tell as soon as I turn it on because it sort of pops and >makes a sound like a machine starting up or a computer being turned on.? >It is usually pretty quiet when I turn it on.If a malfucntioning cable, or device is plugged into the Xpander when you turn it on, this makes sense. If not I think you may have a power supply problem. I know you said it was recently re-capped but (sorry) that is the most likly.? I am hoping this information is characteristic of a problem you have seen >before.? I have no trouble replacing components, but my diagnosing skills >are limited.?These exact symptoms are new for me. However anytime chips can randomly come loose from the sockets, symptoms can be strange. I have seen other things behave badly ( freaking out when something is plugged into it)? ? And it is almost always a ground problem. Anyway try these things, let me know : - ) Best Luck Karl Schmeer --- On Mon, 3/15/10, Chase Smith <plus_321@yahoo. com> wrote: From: Chase Smith <plus_321@yahoo. com> Subject: Re: [xpantastic] Stuck note / tunings fail To: xpantastic@yahoogro ups.com Date: Monday, March 15, 2010, 1:07 AM ? Thanks a lot for helping me out here, I really appreciate it. I opened it up and press on all the socketed ICs and reseated the connecting cables.? After I did this I was able to get it to tune all voices, but it's really strange.? It will tune them, but as soon as a plug in a cable for the voices or cvs, it will fail the tunings (this was in multimode). It was off for while and I just turned it on and plugged in the main LR cables and put it in single mode and it is passing all tunings and seems to work fine as a poly synth. However, whenever I plug into any of the voice outputs, the pitch and amplitude seem to be glitchy for all of them.? It's like they are being modulated randomly (it kind of reminds me of how the pitch would waiver before I recapped the PS).? The output of the master is fine though.? Also, maybe worthy of note is that whenever I turn it on and it doesn't tune, I can tell as soon as I turn it on because it sort of pops and makes a sound like a machine starting up or a computer being turned on.? It is usually pretty quiet when I turn it on. I am hoping this information is characteristic of a problem you have seen before.? I have no trouble replacing components, but my diagnosing skills are limited.? Thank You, Chase Smith From: Karl Schmeer <shire03@sbcglobal. net> To: xpantastic@yahoogro ups.com Sent: Sun, March 14, 2010 10:06:15 PM Subject: Re: [xpantastic] Stuck note / tunings fail Hi Chase, ? Sounds like the?final VCA is stuck open.? For all voices if in mono keybooard mode. You may have tried this, but ? What happens when you change patches? Same issue? Is the Xpander keyboard mode set to mono? If so what?happens when you change keyboard modes? ? Check the VCF/VCA page. and?make sure?the?final VCA is turned all the way down, and all modulations are turned off or down. ? If it's not the above, then reason dictates a hardware problem.? This may be as simple as opening up the Xpander and reseating the IC's, on the analog board. All chips are in sockets and this is easily acomplished. Just push on them all, to make sure none have come loose. While your at it check to make sure all connectors are Try these things and see if it helps. Let me know what you find, and we can go from there. ? Best Luck ? Karl Schmeer ? ? ? --- On Sun, 3/14/10, plus_321 <plus_321@yahoo. com> wrote: From: plus_321 <plus_321@yahoo. com> Subject: [xpantastic] Stuck note / tunings fail To: xpantastic@yahoogro ups.com Date: Sunday, March 14, 2010, 8:51 PM ? I powered down my xpander and it was working perfectly (pass every tuning all the time after I recapped the ps years ago). I turn it on a few minutes ago and it behaves like there is a note stuck. Playing midi notes will change the note that I hear. Also all tunings fail. I tried a system reset, it did nothing. I tried to change the pedal stuff, but it did nothing. I'm really hoping someone has an idea of what this is. I really want to finish the song I was working on and I kind of need this instrument. Thank You, Chase Smith ------------ --------- --------- ------ Yahoo! Groups Links |
|
|
Re: Stuck note / tunings fail
You are very lucky that you didnt burn anything !
toggle quoted message
Show quoted text
Thats why you should use a DI ! WT ----- Original Message -----
From: "Chase Smith" <plus_321@...> To: <xpantastic@...> Sent: Tuesday, March 16, 2010 2:51 AM Subject: Re: [xpantastic] Stuck note / tunings fail I'm sorry, but I made a really stupid mistake here. When I was working on the song, I ran out of channels on my mixer so I plugged into where I would usually have my pc stereo out (channels 23 and 24). I had never used these channels in this configuration for synths, but I had wired them with XLRs instead of 1/4" so I could use the preamps if I needed them. Well, I either accidentally flipped the switch for phantom power or it was on the whole time and the computer didn't mind. So the Xpander was freaking out because it was getting something like 46 V at the output which it obviously didn't like. |
|
|
Re: Stuck note / tunings fail
Chase Smith
I'm sorry, but I made a really stupid mistake here.? When I was working on the song, I ran out of channels on my mixer so I plugged into where I would usually have my pc stereo out (channels 23 and 24).? I had never used these channels in this configuration for synths, but I had wired them with XLRs instead of 1/4" so I could use the preamps if I needed them. Well, I either accidentally flipped the switch for phantom power or it was on the whole time and the computer didn't mind.? So the Xpander was freaking out because it was getting something like 46 V at the output which it obviously didn't like.? It's kind of embarrassing to admit this, but I'm just happy that there are not major issues here.? Again, thanks a lot for taking the time to read my emails and help me out. Thanks, Chase Smith From: Karl Schmeer To: xpantastic@... Sent: Mon, March 15, 2010 2:27:12 AM Subject: Re: [xpantastic] Stuck note / tunings fail ? Hi Chase, ? ? >?strange.? It will tune them, but as soon as a plug in a cable for the > voices or cvs, it will fail the tunings (this was in multimode). Ahhh, a good clue, Is the mixer / CV generator plugged into the same power outlet as the Xpander. You could have a ground loop problem. Other possibilities: The mixer could have a problem. But that seems unlikly. A more likly? situation is the cable has a short in it and plugging it in shorts the outputs to ground. What are you plugging into the CV jacks? This pedel or midi/CV device might have a ground problem or overvoltage for that matter. Before plugging the mixer or CV generator in to the Xpander again I would get a Voltmeter and check the tip and ring of the cable. Check for shorts, and continuity to ground.? This could be a loose ground connection inside the Xpander. All the problems (now) seem to revolve around the potentiometer display board. Now reseat the chips and check cables on that board. Also look closly at where the jacks are soldered into the circuit board. A loose solder connection here could also cause the symptoms you describe. If you have a soldering Iron, you could reflow the solder on all the output and CV jacks.? ? >Also, maybe worthy of note is that whenever I turn it on and it doesn't >tune, I can tell as soon as I turn it on because it sort of pops and >makes a sound like a machine starting up or a computer being turned on.? >It is usually pretty quiet when I turn it on. If a malfucntioning cable, or device is plugged into the Xpander when you turn it on, this makes sense. If not I think you may have a power supply problem. I know you said it was recently re-capped but (sorry) that is the most likly.? >I am hoping this information is characteristic of a problem you have seen >before.? I have no trouble replacing components, but my diagnosing skills >are limited.? These exact symptoms are new for me. However anytime chips can randomly come loose from the sockets, symptoms can be strange. I have seen other things behave badly ( freaking out when something is plugged into it)? ? And it is almost always a ground problem. Anyway try these things, let me know : - ) Best Luck Karl Schmeer --- On Mon, 3/15/10, Chase Smith <plus_321@...> wrote: From: Chase Smith <plus_321@...> Subject: Re: [xpantastic] Stuck note / tunings fail To: xpantastic@... Date: Monday, March 15, 2010, 1:07 AM ? Thanks a lot for helping me out here, I really appreciate it. I opened it up and press on all the socketed ICs and reseated the connecting cables.? After I did this I was able to get it to tune all voices, but it's really strange.? It will tune them, but as soon as a plug in a cable for the voices or cvs, it will fail the tunings (this was in multimode). It was off for while and I just turned it on and plugged in the main LR cables and put it in single mode and it is passing all tunings and seems to work fine as a poly synth. However, whenever I plug into any of the voice outputs, the pitch and amplitude seem to be glitchy for all of them.? It's like they are being modulated randomly (it kind of reminds me of how the pitch would waiver before I recapped the PS).? The output of the master is fine though.? Also, maybe worthy of note is that whenever I turn it on and it doesn't tune, I can tell as soon as I turn it on because it sort of pops and makes a sound like a machine starting up or a computer being turned on.? It is usually pretty quiet when I turn it on. I am hoping this information is characteristic of a problem you have seen before.? I have no trouble replacing components, but my diagnosing skills are limited.? Thank You, Chase Smith From: Karl Schmeer To: xpantastic@yahoogro Sent: Sun, March 14, 2010 10:06:15 PM Subject: Re: [xpantastic] Stuck note / tunings fail Hi Chase, ? Sounds like the?final VCA is stuck open.? For all voices if in mono keybooard mode. You may have tried this, but ? What happens when you change patches? Same issue? Is the Xpander keyboard mode set to mono? If so what?happens when you change keyboard modes? ? Check the VCF/VCA page. and?make sure?the?final VCA is turned all the way down, and all modulations are turned off or down. ? If it's not the above, then reason dictates a hardware problem.? This may be as simple as opening up the Xpander and reseating the IC's, on the analog board. All chips are in sockets and this is easily acomplished. Just push on them all, to make sure none have come loose. While your at it check to make sure all connectors are Try these things and see if it helps. Let me know what you find, and we can go from there. ? Best Luck ? Karl Schmeer ? ? ? --- On Sun, 3/14/10, plus_321 wrote: From: plus_321 Subject: [xpantastic] Stuck note / tunings fail To: xpantastic@yahoogro ups.com Date: Sunday, March 14, 2010, 8:51 PM ? I powered down my xpander and it was working perfectly (pass every tuning all the time after I recapped the ps years ago). I turn it on a few minutes ago and it behaves like there is a note stuck. Playing midi notes will change the note that I hear. Also all tunings fail. I tried a system reset, it did nothing. I tried to change the pedal stuff, but it did nothing. I'm really hoping someone has an idea of what this is. I really want to finish the song I was working on and I kind of need this instrument. Thank You, Chase Smith ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: ? ? <*> Your email settings: ? ? Individual Email | Traditional <*> To change settings online go to: ? ? ? ? (Yahoo! ID required) <*> To change settings via email: ? ? xpantastic-digest@... ? ? xpantastic-fullfeatured@... <*> To unsubscribe from this group, send an email to: ? ? xpantastic-unsubscribe@... <*> Your use of Yahoo! Groups is subject to: ? ? |
|
|
Re: Stuck note / tunings fail
Hi Chase,
? ? ?strange. It will tune them, but as soon as a plug in a cable for theAhhh, a good clue, Is the mixer / CV generator plugged into the same power outlet as the Xpander. You could have a ground loop problem. Other possibilities: The mixer could have a problem. But that seems unlikly. A more likly situation is the cable has a short in it and plugging it in shorts the outputs to ground. What are you plugging into the CV jacks? This pedel or midi/CV device might have a ground problem or overvoltage for that matter. Before plugging the mixer or CV generator in to the Xpander again I would get a Voltmeter and check the tip and ring of the cable. Check for shorts, and continuity to ground. This could be a loose ground connection inside the Xpander. All the problems (now) seem to revolve around the potentiometer display board. Now reseat the chips and check cables on that board. Also look closly at where the jacks are soldered into the circuit board. A loose solder connection here could also cause the symptoms you describe. If you have a soldering Iron, you could reflow the solder on all the output and CV jacks. ? Also, maybe worthy of note is that whenever I turn it on and it doesn't >tune, I can tell as soon as I turn it on because it sort of pops and >makes a sound like a machine starting up or a computer being turned on. >It is usually pretty quiet when I turn it on.If a malfucntioning cable, or device is plugged into the Xpander when you turn it on, this makes sense. If not I think you may have a power supply problem. I know you said it was recently re-capped but (sorry) that is the most likly. I am hoping this information is characteristic of a problem you have seen >before. I have no trouble replacing components, but my diagnosing skills >are limited.These exact symptoms are new for me. However anytime chips can randomly come loose from the sockets, symptoms can be strange. I have seen other things behave badly ( freaking out when something is plugged into it) And it is almost always a ground problem. Anyway try these things, let me know : - ) Best Luck Karl Schmeer --- On Mon, 3/15/10, Chase Smith <plus_321@...> wrote: From: Chase Smith <plus_321@...> Subject: Re: [xpantastic] Stuck note / tunings fail To: xpantastic@... Date: Monday, March 15, 2010, 1:07 AM ? Thanks a lot for helping me out here, I really appreciate it. I opened it up and press on all the socketed ICs and reseated the connecting cables.? After I did this I was able to get it to tune all voices, but it's really strange.? It will tune them, but as soon as a plug in a cable for the voices or cvs, it will fail the tunings (this was in multimode). It was off for while and I just turned it on and plugged in the main LR cables and put it in single mode and it is passing all tunings and seems to work fine as a poly synth. However, whenever I plug into any of the voice outputs, the pitch and amplitude seem to be glitchy for all of them.? It's like they are being modulated randomly (it kind of reminds me of how the pitch would waiver before I recapped the PS).? The output of the master is fine though.? Also, maybe worthy of note is that whenever I turn it on and it doesn't tune, I can tell as soon as I turn it on because it sort of pops and makes a sound like a machine starting up or a computer being turned on.? It is usually pretty quiet when I turn it on. I am hoping this information is characteristic of a problem you have seen before.? I have no trouble replacing components, but my diagnosing skills are limited.? Thank You, Chase Smith From: Karl Schmeer <shire03@sbcglobal. net> To: xpantastic@yahoogro ups.com Sent: Sun, March 14, 2010 10:06:15 PM Subject: Re: [xpantastic] Stuck note / tunings fail Hi Chase, ? Sounds like the?final VCA is stuck open.? For all voices if in mono keybooard mode. You may have tried this, but ? What happens when you change patches? Same issue? Is the Xpander keyboard mode set to mono? If so what?happens when you change keyboard modes? ? Check the VCF/VCA page. and?make sure?the?final VCA is turned all the way down, and all modulations are turned off or down. ? If it's not the above, then reason dictates a hardware problem.? This may be as simple as opening up the Xpander and reseating the IC's, on the analog board. All chips are in sockets and this is easily acomplished. Just push on them all, to make sure none have come loose. While your at it check to make sure all connectors are Try these things and see if it helps. Let me know what you find, and we can go from there. ? Best Luck ? Karl Schmeer ? ? ? --- On Sun, 3/14/10, plus_321 <plus_321@yahoo. com> wrote: From: plus_321 <plus_321@yahoo. com> Subject: [xpantastic] Stuck note / tunings fail To: xpantastic@yahoogro ups.com Date: Sunday, March 14, 2010, 8:51 PM ? I powered down my xpander and it was working perfectly (pass every tuning all the time after I recapped the ps years ago). I turn it on a few minutes ago and it behaves like there is a note stuck. Playing midi notes will change the note that I hear. Also all tunings fail. I tried a system reset, it did nothing. I tried to change the pedal stuff, but it did nothing. I'm really hoping someone has an idea of what this is. I really want to finish the song I was working on and I kind of need this instrument. Thank You, Chase Smith |
|
|
Re: Stuck note / tunings fail
Chase Smith
Thanks a lot for helping me out here, I really appreciate it. I opened it up and press on all the socketed ICs and reseated the connecting cables.? After I did this I was able to get it to tune all voices, but it's really strange.? It will tune them, but as soon as a plug in a cable for the voices or cvs, it will fail the tunings (this was in multimode). It was off for while and I just turned it on and plugged in the main LR cables and put it in single mode and it is passing all tunings and seems to work fine as a poly synth. However, whenever I plug into any of the voice outputs, the pitch and amplitude seem to be glitchy for all of them.? It's like they are being modulated randomly (it kind of reminds me of how the pitch would waiver before I recapped the PS).? The output of the master is fine though.? Also, maybe worthy of note is that whenever I turn it on and it doesn't tune, I can tell as soon as I turn it on because it sort of pops and makes a sound like a machine starting up or a computer being turned on.? It is usually pretty quiet when I turn it on. I am hoping this information is characteristic of a problem you have seen before.? I have no trouble replacing components, but my diagnosing skills are limited.? Thank You, Chase Smith From: Karl Schmeer To: xpantastic@... Sent: Sun, March 14, 2010 10:06:15 PM Subject: Re: [xpantastic] Stuck note / tunings fail
|
|
|
Re: Stuck note / tunings fail
--- On Sun, 3/14/10, plus_321 wrote:
|
|
|
Stuck note / tunings fail
plus_321
I powered down my xpander and it was working perfectly (pass every tuning all the time after I recapped the ps years ago). I turn it on a few minutes ago and it behaves like there is a note stuck. Playing midi notes will change the note that I hear. Also all tunings fail.
I tried a system reset, it did nothing. I tried to change the pedal stuff, but it did nothing. I'm really hoping someone has an idea of what this is. I really want to finish the song I was working on and I kind of need this instrument. Thank You, Chase Smith |
|
|
Re: Xpander vs. M12
analogholic
Well, this is something I asked myself like 3 years ago when a Matrix-12 showed up for sale locally.
Got in contact with a great musician, who said: "Used to own the Xpander, but got the M12 and have never looked back." The reason was LAYERING! I LOVE the sound of Oberheims, and thought maybe the Xpander + OB-Xa would be a better combo than just the M12. But I got the M12 afterall (and an OB-Xa later:) ) and I am REALLY glad did that. I can just agree the statement above about layering. I?ve done pads on the M12 in "dualmode" that literally blow me away. Could never do this on the Xpander. Well I could "almost", but 3 voices only. It took me a while to get the hang of it...but damn :) Also it layers well, something I don?t think my OB-Xa does, due to different characther in sound and of course that it?s way less flexible. To me (and others) the design REALLY comes to life in the M12. IMO. it?s a little bit like comparing a CS-60 to a CS-80, or rather a JX-8P to a JX-10. And add the detune functions..no contest. Wouldn?t mind an Xpander as well though for live gigs :) |
|
|
Re: Xpanding my horizon
Hi Terje,
--- On Sun, 2/28/10, Terje Winther <terje.winther@...> wrote: From: Terje Winther <terje.winther@...>Good idea, you also might swing out the displays ( board is hinged ) and clean the glass of the VFD's as well as the front panel bezel. It can really spiff it up. I have run across some various interesting failures:You can still find those. - The rotary encoders all work, thankfully. It is just the SchmidtThanx That is exactly the symptom I had. I thought the encoaders were dirty but a little checking with a scope revealed a distoted output of the trigger chip. I used 74HC14 chip. You can get them for cheap. I Changed out U6 and U13 on the potentiometer board. Its faster than taking the encoaders apart and cleaning them but you may have to do this anyway. Then the real problems:Question: when you say unresponsive, I imagine you mean the voices can not be heard, but what about the little green dots on the display? There are dots that show which voices are being played on the Programmer display. Do these not light up? to the next problem...You may know this already but, That button is only active in multi mode. The buttons are just momentary push buttons. You could solder another pushbutton ( Normally open) in it's place, on the bottom of the board with long extension wires. This would be a temporary fix, just so you can access voices 7 - 12. I can think of a some reasons the upper voices (7 - 12) would not play: I am going on the assumption that all voices are set to the same patch. A patch could have a VCA mod by a footswitch residing in voices 7 - 12, causing them to be mute. 1) Voices 7 - 12 turned off in master page. 2) Voices 7 - 12 Pan setting to off. ( in the master page) - Unresponsive buttons. How do you usually solve this? Clean them, orI have had some luck with cleaning them but replacement is better. They used to be readily available, but not so much anymore. I need to replace some of mine, to tell you the truth but still need to find a modern part number. Anyone? The power supply have a fairly high physical hum, so at one point itI have seen the transformer cause hum like this. It is not failed, the metal plates of the transformer have come loose and vibrate with the line frequency. There is no fix short of replacing the transformer. The voltages sound close enough to be OK. If you scope it and there is no appreciable ripple < 50 mv the power supply is probobly OK. BTW It might not be a bad idea to the power supply. The electrolytic caps in the power supply get the most abuse, And are the most likly thing to fail "in anything electronic". Best Luck Karl Schmeer |
|
|
Re: Xpanding my horizon
Terje Winther
Hi all, and thanks for all the input regarding the Matrix-12 repair
that I am doing. The unit is in very good shape and sounds good. Among other things all the displays are fine, panel is good, wooden sides are in fine shape, and all keys (except one broken) looks good. There are some trouble manuvering the synth, as several buttons don?t respond. It was kind of dirty before I started working on it, so I guess several of the buttons needs to be cleaned, as I had to do with they keys (both keytops and key contacts). I have run across some various interesting failures: - One voice is dead, and I have pinpointed this to the fact that the VCA output (leg no. 14) of the CEM3372 is dead. All else on the chips works as it should; inputs, VCF sections and all. It is just the VCA that is gone. Usually when a CEM chip fails it is completely dead, so this was a puzzle for me. Swapping chips with other voices turns it into a working voice. So a new chip is needed here, then. - The rotary encoders all work, thankfully. It is just the Schmidt trigger chips that seems to mailfunction, just as Karl Schmeer suggested (thanks!). If I rotate the encoder with a very specific speed - slowly, but not too slowly - I can make it increase somewhat, but it is difficult. Reducing with the same encoder is no problem. Need new chips probably, or maybe just clean up? Then the real problems: - Only voices 1-6 can be heard. Internally all voices (both 1-6 and 7-12) seems to work fine (I can scope it all). This might be connected to the next problem... - The "Voices 1-6 / Voices 7-12" button is unresponsive, so I have no way to see if the second voice board is turned off or not. Are there any workaround for this? - Unresponsive buttons. How do you usually solve this? Clean them, or change them? It seems to me that there are standard momentary buttons underneath the large black front panel buttons. The power supply have a fairly high physical hum, so at one point it probably needs to be changed. The internal power is stable, but a little bit off spec, like +12.1 and -11.82. Is this to much off? I hope not, because that means I have to rebuild the whole power, with new regulator transistors and all. Terje Winther terje.winther@... |
|
|
NOS VFD displays on eBay
John Pallister
If anyone is looking for a spare/replacement VFD display for their
Xpander, there is one (possibly more) on eBay at the moment, ex-Japan (but see below). The price of about USD145 is not exactly cheap, but these things are pretty rare these days... Search for "Noritake-Itron VFD for OBERHEIM Xpander and Matrix-12", item no. 170448856713. This auction only has 9 hours left to run, but there is a page at (via ) for the same display(s) that has an email address. (And they're out of stock on CEM3374s, before you get too excited.) As (s)he points out, the FG405B2 is not exactly the same as the original FG405A2 part used in the Xpander/Matrix-12. Apparently the PCBs are the same, so it should fit in the display board, but it isn't clear whether they'll fit into the holes in the front panel. I can't find datasheets for either display on the web to confirm this. I thought about buying one, but I have decided against it. If/when the displays on my Xpander go, I'll try and make a replacement display board that uses more modern displays. Cheers, John :^P -- John Pallister john@... john@... |
|
|
Re: Xpanding my horizon
--- On Tue, 2/23/10, Terje Winther wrote:
|
|
|
Re: Xpanding my horizon
Terje Winther
Hi all,
I am well into the service of the Matrix-12. Surprisingly, there are a lot of things that works, even though it all seems a bit worn. I am slowly learning to program this giant, so that I don?t do any errors out of mistakes. There are a few hardware parts that need to be changed (a key is broken, the levels are scratchy, number "3" on the numeric keypad is not responsive etc.), but today I came across a peculiar problem: it seems that this unit is in 5-voice mode. Voice 6 seems to be dead, and the unit is just jumping over that voice when cycling voices, so there are never any "dead" voices. Is this some clever trick of the logic, or has the synth itself detected that one voice is dead? It does sound fat, though :-) Terje Winther terje.winther@... |
|
|
Re: Xpander Front Panel Cleaning
--- On Fri, 2/19/10, Mel wrote:
|
|
|
Re: Xpander Front Panel Cleaning
I would like to know this too as my Xpander has the same problem.
toggle quoted message
Show quoted text
WT ----- Original Message -----
From: "Tony Cappellini" <cappy2112@...> To: <xpantastic@...> Cc: <tares@...> Sent: Friday, February 19, 2010 8:19 PM Subject: Re: [xpantastic] Re: Xpander Front Panel Cleaning A specific name would be helpful. There are many chemical sprays for cleaning computers, some of which would probably dissolve the Xpander's Front panel On Fri, Feb 19, 2010 at 7:20 AM, envia94 <tares@...> wrote:
|
|
|
Re: Xpander Front Panel Cleaning
A specific name would be helpful.
toggle quoted message
Show quoted text
There are many chemical sprays for cleaning computers, some of which would probably dissolve the Xpander's Front panel On Fri, Feb 19, 2010 at 7:20 AM, envia94 <tares@...> wrote:
|
to navigate to use esc to dismiss