Wow Karl,
are you sure you haven't designed this synth?
You definately have amazing knowledge on it's design!
I will replace all parts you mentioned except for the DAC wich I will
at least reseat!
In return for your help let me know if you're ever in dire need of a
fluorescent display for your own use ofcourse!
I was smart enough about 10 years ago to buy a couple NOC ones spare
just in case and I know they are impossible to find!
I'll let you know how it goes!
Thanks,Takis!
toggle quoted message
Show quoted text
--- In xpantastic@..., "Karl" <shire03@...> wrote:
Hi Takis,
The other caps are Cx33 and Cx37 with x being 2,3,4,5,6,7 for each
voice respectivly. And Yes they are the same 2.2uF 50V Make sure they
are 50V rating. and correct polarity (You probobly knew that)
But before you replace those, try this.You are saying you are having
problems with all the voices right?
This points to the main DAC/Tuming circuit as you have already
guessed.
I would look closely at:
U811 The DAC
U816,U805 Multiplexer 4051
U812,U815,U813 Op Amps TLO81,TLO84,TLO81
U814 Analog Switch 4053
Any of these parts failing could cause tuning problems like you
describe.
Now, before you replace them carfully pull them from the sockets and
re-seat them. Sometimes corrosion on the socket/chip lead can cause
a "not to good" connection. Also before I replaced them I would
reflow the solder on the bottom of the board, as bad solder joints
could also cause this.
If this does not work replace em. All except the DAC are readily
available. I would wait till you replaced the other chips before you
went searching for this DAC to see if any others are the cause. If
one of the chips have failed, I would bet on the mux or analog switch.
It would not hurt to replace the capacitors I mentioned above, as
they are probobly on their way out anyway.
Let Me Know How It Goes
Karl
--- In xpantastic@..., "takisdamaschis"
<takisdamaschis@> wrote:
Hi Carl,
yes I replaced all six Cx49 capacitors!
What number are the other ones you're refering to?Are they also
2.2uF?
Many thanks,Takis.
--- In xpantastic@..., "Karl" <shire03@> wrote:
Hello takisdamaschis,
When you say output capacitors, are you talking about the small
2.2uF
Cx49 at the edge of the voice board? There is one for each voice.
There is also one of these at the output of each VCO feeding the
VCF
If these go you can have tuning problems. Also, try resetting the
software.( hold sown clear and turn power On)
Karl
--- In xpantastic@..., "takisdamaschis"
<takisdamaschis@> wrote:
Hi everyone, my xpander seems to fail the VCO tune test
randomly!some
voices fail during one test and pass on the next! there is no
cosistancy on the voices that fail,it can be any one of them!
Some
times(rarely) the vco test passes! I have the same problem
sometimes
with the Resonance and VCF but not as often!
I have totally rebuilt the power supply,changed the battery and
output
bypass capacitors!All currents measure right so this is not a
voltage
supply problem!
The only other part I can think of is the DAC or maybe the
Timer?
Any thoughts?
Takis.
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Yeah, I hang at Musicplayer among other places. Sorry, I misread you. Ok, only from the pedal. In return, you might check how I can get my pitchwheel springloaded in the Mini with a range of 2 semitones (If you didn?t already answer that already at Musicplayer:)...) Cheers --- In xpantastic@..., PeWe <ha-pewe@...> wrote:
Hi !
Are you the one I see in the musicplayerforums too ... ? :-)
Would be a great idea to ask this tech for a sync-mod being
controlled by a Moog Model 1120 CV pedal.
NOT the wheel and NOT the envelope as control-sources for the pitch of the synced OSC,- just only the pedal.
OSC 2 synced to OSC 1
sync-sweep-control source (pedal) switchable off/on, sync function
switchable off/on (both maybe by footswitches)
OSC pitch-reset to keyboard voltage only if pedal as a control source is defeated by the switch.
We had a sync function in our "Midimuck" ( = racked Minimoog) in 1989,
This could be controlled by Midi CC #4,- but w/ a real mini it has
to be a CV pedal.
I only have a fronpanel of the Midimuck left over unfortunally. The
tech from the past is unavailable and I cannot find the hand drawn
schematics.
There is probably 1 prototype working in a studio,- I?ll ask the owner if the machine is there or trashed meanwhile, if not, if it?s working and if I can have a look into it. It was done w/ original Minimoog
circuit boards.
B.t.w., - I had such a mod also for the Prophet 5 in the 80th/90th,- CV-pedal controlled the sync via the polymod and was switchable too.
Was another story because of bypassing the Z80 proc and cutting lanes ond so on ...
let me know please
good luck
PeWe
analogholic schrieb:
Hi PeWe,
My problem is that I?m not a tech by far, but get cool ideas all
the time...
I got in touch with a tech here in Sweden the other day.
I can ask him about the Pedal/Modwheel controlling the sync if you
want.
Cheers
-
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Hi !
Are you the one I see in the musicplayerforums too ... ? :-)
Would be a great idea to ask this tech for a sync-mod being controlled
by a Moog Model 1120 CV pedal.
NOT the wheel and NOT the envelope as control-sources for the pitch of
the synced OSC,- just only the pedal.
OSC 2 synced to OSC 1
sync-sweep-control source (pedal) switchable off/on, sync function
switchable off/on (both maybe by footswitches)
OSC pitch-reset to keyboard voltage only if pedal as a control source
is defeated by the switch.
We had a sync function in our "Midimuck" ( = racked Minimoog) in 1989,
-
This could be controlled by Midi CC #4,- but w/ a real mini it has to
be a CV pedal.
?
I only have a fronpanel of the Midimuck left over unfortunally. The
tech? from the past is unavailable and I cannot find the hand drawn
schematics.
There is probably 1 prototype working in a studio,- I?ll ask the owner
if the machine is there or trashed meanwhile, if not, if it?s working
and if I can have a look into it. It was done w/ original Minimoog
circuit boards.
B.t.w., - I had such a mod also for the Prophet 5 in the 80th/90th,-
CV-pedal controlled the sync via the polymod and was switchable too.
Was another story because of bypassing the Z80 proc and cutting lanes
ond so on ...
let me know please
good luck
PeWe
analogholic schrieb:
toggle quoted message
Show quoted text
Hi PeWe,
My problem is that I?m not a tech by far, but get cool ideas all the
time...
I got in touch with a tech here in Sweden the other day.
I can ask him about the Pedal/Modwheel controlling the sync if you
want.
Cheers
-
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Hi PeWe, My problem is that I?m not a tech by far, but get cool ideas all the time... I got in touch with a tech here in Sweden the other day. I told him about the "Studio Electronics mod" (which they had on their Midimoog/Midimini), where you can sweep the synced Osc with the filter envelope ala Prophet 5. He said, no problem. He?s going to add a switch or two for on/off, and a knob for depth. I?m going to decide if I want to sync both Osc 2 and 3 to Osc 1, or just Osc 2. I can ask him about the Pedal/Modwheel controlling the sync if you want. I sold my Prodigy the other day, where the sync sounds phenomenal. You know, having Osc 2 synced, while Osc 3 is not, with its natural drift, sounds very exciting to me. You won?t of course have any LFO then, but that would come from the Kenton Pro Solo in that case. Cheers --- In xpantastic@..., PeWe <ha-pewe@...> wrote:
Hi analogholic !
I?d be interested in more details of a Minimoog D sync-mod if
possible. I had that in mind since a long time, but couldn?t find a tech who could do it the way I imagined.
I?d like to control the sync-sweep effect by a Moog 1120 CV pedal,- not by the mod-wheel or by one of the envelopes.
The general prob is w/ the Mini,- any device connected to the Mini?s CV-inputs adds voltage to the unit. To change that, you?d have to
disconnect the device ( pedal).
It?s somewhat uncomfortable to plug/ unplug a CV-pedal during performance. So this has to be switchable on/off as a mod source of one of the
oscillators frequency/pitch w/ a sync mod installed and hard sync
switched to on.
Prob No. 2,- if the pedal is not in use but still connected,- how to reset the oscillators pitch to normal condition and regardless of the pedals angle (= setting/position of its pot ) in the moment you?d defeat it from the circuitry by a switch ?
Any idea ?
analogholic schrieb:
I?m gonna syncmod the Mini next...hope that?s not like cursing in
church :)
Cheerio
|
Hi Takis, The other caps are Cx33 and Cx37 with x being 2,3,4,5,6,7 for each voice respectivly. And Yes they are the same 2.2uF 50V Make sure they are 50V rating. and correct polarity (You probobly knew that) But before you replace those, try this.You are saying you are having problems with all the voices right? This points to the main DAC/Tuming circuit as you have already guessed. I would look closely at: U811 The DAC U816,U805 Multiplexer 4051 U812,U815,U813 Op Amps TLO81,TLO84,TLO81 U814 Analog Switch 4053 Any of these parts failing could cause tuning problems like you describe. Now, before you replace them carfully pull them from the sockets and re-seat them. Sometimes corrosion on the socket/chip lead can cause a "not to good" connection. Also before I replaced them I would reflow the solder on the bottom of the board, as bad solder joints could also cause this. If this does not work replace em. All except the DAC are readily available. I would wait till you replaced the other chips before you went searching for this DAC to see if any others are the cause. If one of the chips have failed, I would bet on the mux or analog switch. It would not hurt to replace the capacitors I mentioned above, as they are probobly on their way out anyway. Let Me Know How It Goes Karl --- In xpantastic@..., "takisdamaschis" <takisdamaschis@...> wrote:
Hi Carl,
yes I replaced all six Cx49 capacitors!
What number are the other ones you're refering to?Are they also
2.2uF? Many thanks,Takis.
--- In xpantastic@..., "Karl" <shire03@> wrote:
Hello takisdamaschis,
When you say output capacitors, are you talking about the small
2.2uF Cx49 at the edge of the voice board? There is one for each voice.
There is also one of these at the output of each VCO feeding the
VCF If these go you can have tuning problems. Also, try resetting the
software.( hold sown clear and turn power On)
Karl
--- In xpantastic@..., "takisdamaschis"
<takisdamaschis@> wrote:
Hi everyone, my xpander seems to fail the VCO tune test
randomly!some voices fail during one test and pass on the next! there is no
cosistancy on the voices that fail,it can be any one of them!
Some times(rarely) the vco test passes! I have the same problem
sometimes with the Resonance and VCF but not as often!
I have totally rebuilt the power supply,changed the battery and
output bypass capacitors!All currents measure right so this is not a
voltage supply problem!
The only other part I can think of is the DAC or maybe the
Timer? Any thoughts?
Takis.
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Hi Karl, Yeah, I was kind of blown away myself that Doidic answered, since he is the president of Line 6! It was a "long shot", but I thought what the heck. I think he is very proud of this legendary beast :) (Who wouldn?t be?) And you?re very welcome btw! Hmmm, yes, I?m thinking about doing a recap myself, since our moderator Tiitu did just that not long ago, which reminds me of a cool mod he mentioned that supposedly would make this beasts sound even better. But I?m gonna wait a week or so before posting that you can soak the envelope mod up first. And I?ll probably wear a raincoat or something, just in case rotten tomatoes and eggs come flying :) Cheerio Hi,
Wow, I am impressed that Michel Doidic even reponded to this after 25 years. He obviously pulled out the schematics and gave it some
thought. Very kind of him. And thanks to analogholic for having the
guts to try. I am planning to overhaul (re-battary and recap) my M12
soon. I might try this mod on one of my voices. I will report back If I do.
Karl
--- In xpantastic@..., "analogholic" <publik@> wrote:
Hi everyone,
When I read the "percussive like patches"-thread, I was reminded
that
I while ago (when the Matrix 12 was my only analog synth) that I (as
many others) was a bit frustrated with the M12?s slow enevelopes.
SoI wrote an email to one of the creators of this beast(Michel Doidic)
and asked what could be done. Here is our conversation:
"Mr Ryle, Mr Doidic, first off I want to thank you for being part of
designing (among other things) the fantastic Oberheim Matrix 12.
I have the incredible luck to have found one (Matrix 12) for sale in
Sweden. Although this is very "off topic", I would be incredibly
grateful and happy if you guys could try (who else could?) answer the
following question: Do you think it would be possible in some way to
modify the envelopes of the Matrix 12 to be faster ?
I know they are software envelopes, but today there are a lot of
softEnvs that are snappy, also on at least two analog synths which have softwareEnvs (one is Studio Electronics Se-1/x) where if you
changed a resistor on the motherboard, the software envelopes became
dramatically faster and snappier, almost at Minimoog speed.
Could it be enough to change resistors in the right place, or
would it be necesarry to recode/reprogram the whole software for the Matrix
12? I know this a hard question, but a solution,if possible,
would mean that a fantastic synth would become the greatest of them all
IMHO.
I thank you once again and send you my best
regards Attila"
His answer:
"Hi Attila, To do the job right would be very difficult because,
as you noticed, the envelopes are generated by the code of the 6809
microprocessor. Short of using a faster 6809 (assuming that you could
get one) and modifying the code there is not much which can be
done. The Matrix 6 and 12 were designed about 25 years ago, and
microprocessors where a lot slower back then. There is still a
bit of
hope however. The fastest time for the envelopes is about 2
milliseconds.
This could be reduce to 1 ms by changing RX51 for the VCA (where X will be 3, 4, 5, 6 or 7 according to which of the six voice it
controls on each of the two voice boards) from 18K to 9.1K.
The next fastest time is set by the microprocessor and an analog
smoothing filter on the voltage control circuit (= Sample and Hold).
This time is set not only by the software but also by a resistor RX14
on each of the main voice PCB for the VCA control and by RX10 for the
VCF frequency control.
You may want to try reducing these resistors from their original
1 M
Ohm value to let say 500K Ohm. This will reduce that time from about
7 ms to about 3.5 ms. The draw back however is that you may get more
discontinuity in the shape of the modulation.
The next fastest times however will still be determined by the 6809
software and that will not change. Give it a try on one of the voice
and see if that goes toward what you want.
Hope that this helps a bit. Michel Doidic Line 6 CTO"
OK guys, what do you think?
I changed a resistor in my SE-1, and it become snappier (not
fantastic, but better)
Also, the Chroma has a reputaion of very slow envelopes, but same
thing there, if you remove a resistor or change it to a lower value,
envelopes supposedly become faster.
I would even go so far to check out the possibilities of putting in a
faster processor and find someone to recode the software.
Brainstorming please begin :)
|
Hi Carl,
yes I replaced all six Cx49 capacitors!
What number are the other ones you're refering to?Are they also 2.2uF?
Many thanks,Takis.
toggle quoted message
Show quoted text
--- In xpantastic@..., "Karl" <shire03@...> wrote:
Hello takisdamaschis,
When you say output capacitors, are you talking about the small 2.2uF
Cx49 at the edge of the voice board? There is one for each voice.
There is also one of these at the output of each VCO feeding the VCF
If these go you can have tuning problems. Also, try resetting the
software.( hold sown clear and turn power On)
Karl
--- In xpantastic@..., "takisdamaschis"
<takisdamaschis@> wrote:
Hi everyone, my xpander seems to fail the VCO tune test randomly!some
voices fail during one test and pass on the next! there is no
cosistancy on the voices that fail,it can be any one of them!Some
times(rarely) the vco test passes! I have the same problem sometimes
with the Resonance and VCF but not as often!
I have totally rebuilt the power supply,changed the battery and output
bypass capacitors!All currents measure right so this is not a voltage
supply problem!
The only other part I can think of is the DAC or maybe the Timer?
Any thoughts?
Takis.
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Hi All, I am thinking about trying this, but can anyone really tell the difference in one thousandth of a second. It seems like only a scope could tell the difference. And looking at the schematics changing Rx51 will only affect the VCA in the filter chip. No other destinations, sorry. The second mod looks more promising as this is a whole string of 1M resistors in the Sample and Hold Circuit. One for each Voltage Controlled Input In the Circuit VCO1,PW1,VCO-VOL1,VCO2 etc... This would affect any modulation source used. ENV, LFO and so on. As Mr Doidic points out "you may get more discontinuity in the shape of the modulation". Maybe some experementation would be in order here. My guess is, if this value was too small the S/H cap will discharge too rapidly. Causing a bumpy shape to an otherwise smooth envelope. If I do try this I will let yal know. Karl --- In xpantastic@..., William Cason <randycason102@...> wrote:
Wow, that's very interesting.? I would love to see faster envelopes
on my M12; I'm wondering if that mod works for all destinations of that env? ?
I'm trying to figure out if I have the guts to try it... anyone else? ?
Randy
--- On Tue, 9/9/08, analogholic <publik@...> wrote:
From: analogholic <publik@...>
Subject: [xpantastic] Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers To: xpantastic@...
Date: Tuesday, September 9, 2008, 4:52 AM
Hi everyone,
When I read the "percussive like patches"-thread, I was reminded that I while ago (when the Matrix 12 was my only analog synth) that I (as many others) was a bit frustrated with the M12?s slow enevelopes.
SoI wrote an email to one of the creators of this beast(Michel Doidic) and asked what could be done. Here is our conversation:
"Mr Ryle, Mr Doidic, first off I want to thank you for being part of designing (among other things) the fantastic Oberheim Matrix 12.
I have the incredible luck to have found one (Matrix 12) for sale in Sweden. Although this is very "off topic", I would be incredibly
grateful and happy if you guys could try (who else could?) answer the following question: Do you think it would be possible in some way to modify the envelopes of the Matrix 12 to be faster ?
I know they are software envelopes, but today there are a lot of
softEnvs that are snappy, also on at least two analog synths which
have softwareEnvs (one is Studio Electronics Se-1/x) where if you
changed a resistor on the motherboard, the software envelopes became dramatically faster and snappier, almost at Minimoog speed.
Could it be enough to change resistors in the right place, or would
it be necesarry to recode/reprogram the whole software for the Matrix 12? I know this a hard question, but a solution,if possible, would
mean that a fantastic synth would become the greatest of them all
IMHO.
I thank you once again and send you my best
regards Attila"
His answer:
"Hi Attila, To do the job right would be very difficult because, as
you noticed, the envelopes are generated by the code of the 6809
microprocessor. Short of using a faster 6809 (assuming that you could get one) and modifying the code there is not much which can be done.
The Matrix 6 and 12 were designed about 25 years ago, and
microprocessors where a lot slower back then. There is still a bit of hope however. The fastest time for the envelopes is about 2
milliseconds.
This could be reduce to 1 ms by changing RX51 for the VCA (where X
will be 3, 4, 5, 6 or 7 according to which of the six voice it
controls on each of the two voice boards) from 18K to 9.1K.
The next fastest time is set by the microprocessor and an analog
smoothing filter on the voltage control circuit (= Sample and Hold). This time is set not only by the software but also by a resistor RX14 on each of the main voice PCB for the VCA control and by RX10 for the VCF frequency control.
You may want to try reducing these resistors from their original 1 M Ohm value to let say 500K Ohm. This will reduce that time from about 7 ms to about 3.5 ms. The draw back however is that you may get more discontinuity in the shape of the modulation.
The next fastest times however will still be determined by the 6809
software and that will not change. Give it a try on one of the voice and see if that goes toward what you want.
Hope that this helps a bit. Michel Doidic Line 6 CTO"
OK guys, what do you think?
I changed a resistor in my SE-1, and it become snappier (not
fantastic, but better)
Also, the Chroma has a reputaion of very slow envelopes, but same
thing there, if you remove a resistor or change it to a lower value, envelopes supposedly become faster.
I would even go so far to check out the possibilities of putting in a faster processor and find someone to recode the software.
Brainstorming please begin :)
|
mm123 ah wrote: I'm trying to find a CEM 3374. Please email me at minime123 AT onebox DOT com (and not this hotmail account) if you've got one for sale. We've also got original used Oberheim Xpander encoders we'd consider trading (for a cem3374 ONLY). Thanks.
Mini
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
VINTAGE SYNTH DEALER
-We Buy, Sell & Trade Analog Synths
-Huge Selection, Years of Experience, Reliable Service
-Visit us at (redirects)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
I saw some of these (CEM3374) on sale on EBay last month. I bid 71 pounds but the total was 73. That shows what the going price is - I think. Cheers, Jeremy
|
I'm trying to find a CEM 3374. Please email me at minime123 AT onebox DOT com (and not this hotmail account) if you've got one for sale.
We've also got original used Oberheim Xpander encoders we'd consider trading (for a cem3374 ONLY).
Thanks.
Mini
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
VINTAGE SYNTH DEALER
-We Buy, Sell & Trade Analog Synths
-Huge Selection, Years of Experience, Reliable Service
-Visit us at (redirects)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
________________________________
To: xpantastic@...
From: plus_321@...
Date: Tue, 2 Sep 2008 12:05:45 -0700
Subject: Re: [xpantastic] It's official- my Xpander is sick
What about the DAC Mono test (pass or fail)? I will guess that you can probably fix this by recapping the power supply board. When I got my Xpander I had issues with the tuning tests and it being terribly out of tune and a recap fixed it.
Chase
Tony Cappellini wrote:
It looks like I won't need to do an A/B comparison with Jeremy's wave file, I can easily hear now that my Xpander is not working well.
Prior to this and the reason I had posted a message looking for someone local to the SF Bay Area was that only on 1 patch did my Xpander sound very bad.
I had found one voice which was flaky, so I turned it off.
Recently, I happen to hit several keys at once and could hear the vcos being grossly out of tune.
After trying to tune everything, I get FAIL across the board.
In the past, when I would see FAIL after running autotune, I would wait 30 min, run it again and all tests would pass. This is not the case now.
Fortunately, I've got a few spare CEMs which I hope are all working, that I can use to troubleshoot with.
I haven't looked at the service manual in years- I hope there are some measurements I can make with a voltmeter to give me some ideas.
I can probably borrow a scope to check for ripple on the output of the PS but don't really know how much ripple would be excessive for the XP PS.
All other front panel functions & midi appear to be working normally, so it's probably not likely to be a PS issue.
_________________________________________________________________
Get more out of the Web. Learn 10 hidden secrets of Windows Live.
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|
Re: The Status of my Autotune & DAC Tests was Re: Re: It's official- my Xpander is sic
Since the VFD's have a limited life, you may not want to leave them on
all the time.
toggle quoted message
Show quoted text
On Tue, Sep 9, 2008 at 4:17 PM, William Cason <randycason102@...> wrote: Hmmm, never thought of that one!
Randy
--- On Tue, 9/9/08, Karl <shire03@...> wrote:
From: Karl <shire03@...>
Subject: The Status of my Autotune & DAC Tests was Re: [xpantastic] Re: It's
official- my Xpander is sick
To: xpantastic@...
Date: Tuesday, September 9, 2008, 1:03 AM
Hello Randy,
Sounds right to me. I was thinking of the times I have seen techs
leave the synth plugged in and powered up to avoid dumping the memory.
It takes guts but some guys do it.
Best Regards
Karl
--- In xpantastic@yahoogro ups.com, William Cason <randycason102@ ...>
wrote:
If your xpander is not plugged into anything (e.g. the wall) while
unsoldering the battery, I it shouldn't matter if the iron is grounded
or not because there will be no >circuit to complete! Just make sure
your xpander's not plugged in, and its chassis isn't touching the same
ground that the iron's grounded to (like the chassis of another
plugged-in device) and you should be OK.
MHO,
Randy
--- On Sun, 9/7/08, Tony Cappellini cappy2112@.. . wrote:
From: Tony Cappellini cappy2112@.. .
Subject: Re: The Status of my Autotune & DAC Tests was Re: [xpantastic] Re: It's official- my Xpander is sick
To: xpantastic@yahoogro ups.com
Date: Sunday, September 7, 2008, 12:11 PM
6.6 V seems very strange for the memory power supply. The battary
might need changing. The Service manual reads that this should be 4.4 V with power on, and
2.xV with power off.
With power off, the voltage reading is correct.
I will probably change the battery too, since it's been about 10 years
after it was changed last.
If you are re-flowing the + side of this circuit ( M+5V) you better
make sure you have an un-grounded soldering Iron. If not
the +Mem supply will be shorted to ground and then the MEM will be
lost. I will have the solder tech where I work do all of this for me since
he does soldering all day long.
I dont trust myself soldering on pcbs. He has a nice temperature
controlled iron with many removable tips.
Hope I caught you in time. I havne't heard of an ungrounded soldering iron before, but I assume
you mean that the iron should not have the ground prong of the
power cord connected. This is easily done with an adapter.
I notice in the Xpander schematics D4 exsists twice. One is a diode
at the top edge of the board the other is an LED for the LFO. Now I The D4 I'm referring to is on the Processor board-not the voice or pot
board. This is how the service manual refers to it.
If this is shiny brown, this may be soldering flux. This should
always be cleaned off the circuit board.
After about 5 - 10 years this will eat the solder and cause problems It doesn't look like flux too me, and is far enough away from where
the solder flux would have been when it was soldered.
Well, I be talkin about U811 the main DAC which feeds the voice
board. The MP7614C-4 was mad by EXAR and is obsolete per their web
site, and the HS3140C-4 was made by SIPEX and is also obsolete. I googled for this part, and many hits were found on websites that
specialize in getting rare parts.
They want orders of $100 or more.
It might not be a bad idea for us to do a group purchase of these, if
we could find a supplier who would sell us a small order.
I suppose with digging you can find this part out there somewhere
(repair shop or part house which specializes in obsolete parts but
you will pay quite a bit). I wish there was a cross reference online that would tell you which
commercial devices also used these components
It would be much easier looking for an appliance than a chip.
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Wow, that's very interesting.? I would love to see faster envelopes on my M12; I'm wondering if that mod works for all destinations of that env?
?
I'm trying to figure out if I have the guts to try it... anyone else?
?
Randy
|
--- On Tue, 9/9/08, analogholic wrote:
From: analogholic
Subject: [xpantastic] Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
To: xpantastic@...
Date: Tuesday, September 9, 2008, 4:52 AM
Hi everyone,
When I read the "percussive like patches"-thread, I was reminded that
I while ago (when the Matrix 12 was my only analog synth) that I (as
many others) was a bit frustrated with the M12?s slow enevelopes.
SoI wrote an email to one of the creators of this beast(Michel Doidic)
and asked what could be done. Here is our conversation:
"Mr Ryle, Mr Doidic, first off I want to thank you for being part of
designing (among other things) the fantastic Oberheim Matrix 12.
I have the incredible luck to have found one (Matrix 12) for sale in
Sweden. Although this is very "off topic", I would be incredibly
grateful and happy if you guys could try (who else could?) answer the
following question: Do you think it would be possible in some way to
modify the envelopes of the Matrix 12 to be faster ?
I know they are software envelopes, but today there are a lot of
softEnvs that are snappy, also
on at least two analog synths which
have softwareEnvs (one is Studio Electronics Se-1/x) where if you
changed a resistor on the motherboard, the software envelopes became
dramatically faster and snappier, almost at Minimoog speed.
Could it be enough to change resistors in the right place, or would
it be necesarry to recode/reprogram the whole software for the Matrix
12? I know this a hard question, but a solution,if possible, would
mean that a fantastic synth would become the greatest of them all
IMHO.
I thank you once again and send you my best
regards Attila"
His answer:
"Hi Attila, To do the job right would be very difficult because, as
you noticed, the envelopes are generated by the code of the 6809
microprocessor. Short of using a faster 6809 (assuming that you could
get one) and modifying the code there is not much which can be done.
The Matrix 6 and 12 were designed about 25
years ago, and
microprocessors where a lot slower back then. There is still a bit of
hope however. The fastest time for the envelopes is about 2
milliseconds.
This could be reduce to 1 ms by changing RX51 for the VCA (where X
will be 3, 4, 5, 6 or 7 according to which of the six voice it
controls on each of the two voice boards) from 18K to 9.1K.
The next fastest time is set by the microprocessor and an analog
smoothing filter on the voltage control circuit (= Sample and Hold).
This time is set not only by the software but also by a resistor RX14
on each of the main voice PCB for the VCA control and by RX10 for the
VCF frequency control.
You may want to try reducing these resistors from their original 1 M
Ohm value to let say 500K Ohm. This will reduce that time from about
7 ms to about 3.5 ms. The draw back however is that you may get more
discontinuity in the shape of the modulation.
The next
fastest times however will still be determined by the 6809
software and that will not change. Give it a try on one of the voice
and see if that goes toward what you want.
Hope that this helps a bit. Michel Doidic Line 6 CTO"
OK guys, what do you think?
I changed a resistor in my SE-1, and it become snappier (not
fantastic, but better)
Also, the Chroma has a reputaion of very slow envelopes, but same
thing there, if you remove a resistor or change it to a lower value,
envelopes supposedly become faster.
I would even go so far to check out the possibilities of putting in a
faster processor and find someone to recode the software.
Brainstorming please begin :)
|
Re: The Status of my Autotune & DAC Tests was Re: Re: It's official- my Xpander is sick
Hmmm, never thought of that one!
?
Randy
|
--- On Tue, 9/9/08, Karl wrote:
From: Karl
Subject: The Status of my Autotune & DAC Tests was Re: [xpantastic] Re: It's official- my Xpander is sick
To: xpantastic@...
Date: Tuesday, September 9, 2008, 1:03 AM
Hello Randy, Sounds right to me. I was thinking of the times I have seen techs leave the synth plugged in and powered up to avoid dumping the memory. It takes guts but some guys do it. Best Regards Karl --- In xpantastic@yahoogro ups.com, William Cason wrote: > > If your xpander is not plugged into anything (e.g. the wall) while unsoldering the battery, I it shouldn't matter if the iron is grounded or not because there will be no >circuit to complete! Just make sure your xpander's not plugged in, and its chassis isn't touching the same ground that the iron's grounded to (like the chassis of another >plugged-in device) and you should be OK. > > MHO, > Randy > > --- On Sun, 9/7/08, Tony Cappellini cappy2112@.. . wrote: > > From: Tony
Cappellini cappy2112@.. . > Subject: Re: The Status of my Autotune & DAC Tests was Re: [xpantastic] Re: It's official- my Xpander is sick > To: xpantastic@yahoogro ups.com> Date: Sunday, September 7, 2008, 12:11 PM > > > > > > > > 6.6 V seems very strange for the memory power supply. The battary > > might need changing. > The Service manual reads that this should be 4.4 V with power on, and > 2.xV with power off. > With power off, the voltage reading is correct. > > I will probably change the battery too, since it's been about 10 years > after it was changed last. > > > If you are re-flowing the + side of this circuit ( M+5V) you better > > make sure you have an un-grounded soldering Iron. If not > > the +Mem supply will be shorted
to ground and then the MEM will be > > lost. > > I will have the solder tech where I work do all of this for me since > he does soldering all day long. > I dont trust myself soldering on pcbs. He has a nice temperature > controlled iron with many removable tips. > > > Hope I caught you in time. > I havne't heard of an ungrounded soldering iron before, but I assume > you mean that the iron should not have the ground prong of the > power cord connected. This is easily done with an adapter. > > > I notice in the Xpander schematics D4 exsists twice. One is a diode > > at the top edge of the board the other is an LED for the LFO. Now I > The D4 I'm referring to is on the Processor board-not the voice or pot > board. This is how the service manual refers to it. > > > If this is shiny brown, this may be soldering flux. This should >
> always be cleaned off the circuit board. > > After about 5 - 10 years this will eat the solder and cause problems > > It doesn't look like flux too me, and is far enough away from where > the solder flux would have been when it was soldered. > > > Well, I be talkin about U811 the main DAC which feeds the voice > > board. The MP7614C-4 was mad by EXAR and is obsolete per their web > > site, and the HS3140C-4 was made by SIPEX and is also obsolete. > > I googled for this part, and many hits were found on websites that > specialize in getting rare parts. > They want orders of $100 or more. > > It might not be a bad idea for us to do a group purchase of these, if > we could find a supplier who would sell us a small order. > > > I suppose with digging you can find this part out there somewhere > > (repair shop or part house which
specializes in obsolete parts but > > you will pay quite a bit). > > I wish there was a cross reference online that would tell you which > commercial devices also used these components > It would be much easier looking for an appliance than a chip. >
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Tony Cappellini wrote: BTW
I know a guy who has the source code for the Xpander, if anyone is
bored and wants to rewrite the OS over a weekend. ;-)
(I don't think he wants to give it away though)
There was talk that Neil Bradley (the guy who engineered Europa for
the Jupiter 6) would look into this, but Europa ended up taking too
much time.
Wow! I'm on a mailing list with Neil Bradley, for reverse engineering software. Small world. Jeremy.
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Hi analogholic !
I?d be interested in more details of a Minimoog D sync-mod if possible.
I had that in mind since a long time, but couldn?t find a tech who
could do it the way I imagined.
I?d like to control the sync-sweep effect by a Moog 1120 CV pedal,- not
by the mod-wheel or by one of the envelopes.
The general prob is w/ the Mini,- any device connected to the Mini?s
CV-inputs adds voltage to the unit. To change that, you?d have to
disconnect the device ( pedal).
It?s somewhat uncomfortable to plug/ unplug a CV-pedal during
performance.
So this has to be switchable on/off as a mod source of one of the
oscillators frequency/pitch w/ a sync mod installed and hard sync
switched to on.
Prob No. 2,- if the pedal is not in use but still connected,- how to
reset the oscillators pitch to normal condition and regardless of the
pedals angle (= setting/position of its pot ) in the moment you?d
defeat it from the circuitry by a switch ?
Any idea ?
analogholic schrieb:
toggle quoted message
Show quoted text
I?m gonna syncmod the Mini next...hope that?s not like cursing in
church :)
Cheerio
?
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Yep, it?s true for both synths,- but that doesn?t make the Xpander or
Matrix12 a bad synth. They have other qualitys.
If the Xpander or M12 is the only synth you have, the slow envelopes
are a disadvantage, but if there are more synths available to work
with,- it?s not so important.
I don?t use the Xpander for bass or very percussive sounds.
The punchiest synths I have are the Minimoog, the MKS80 and the
FM-synths ( TX816 / DX7mkII & TG77).
Tony Cappellini schrieb:
toggle quoted message
Show quoted text
One does not need a scope to experience the slow envelopes on the
Xpander, it is plainly audible.
The same goes for the OB8.
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Hi, Wow, I am impressed that Michel Doidic even reponded to this after 25 years. He obviously pulled out the schematics and gave it some thought. Very kind of him. And thanks to analogholic for having the guts to try. I am planning to overhaul (re-battary and recap) my M12 soon. I might try this mod on one of my voices. I will report back If I do. Karl --- In xpantastic@..., "analogholic" <publik@...> wrote:
Hi everyone,
When I read the "percussive like patches"-thread, I was reminded
that I while ago (when the Matrix 12 was my only analog synth) that I (as many others) was a bit frustrated with the M12?s slow enevelopes.
SoI wrote an email to one of the creators of this beast(Michel Doidic) and asked what could be done. Here is our conversation:
"Mr Ryle, Mr Doidic, first off I want to thank you for being part of designing (among other things) the fantastic Oberheim Matrix 12.
I have the incredible luck to have found one (Matrix 12) for sale in Sweden. Although this is very "off topic", I would be incredibly
grateful and happy if you guys could try (who else could?) answer the following question: Do you think it would be possible in some way to modify the envelopes of the Matrix 12 to be faster ?
I know they are software envelopes, but today there are a lot of
softEnvs that are snappy, also on at least two analog synths which
have softwareEnvs (one is Studio Electronics Se-1/x) where if you
changed a resistor on the motherboard, the software envelopes became dramatically faster and snappier, almost at Minimoog speed.
Could it be enough to change resistors in the right place, or would
it be necesarry to recode/reprogram the whole software for the Matrix 12? I know this a hard question, but a solution,if possible, would
mean that a fantastic synth would become the greatest of them all
IMHO.
I thank you once again and send you my best
regards Attila"
His answer:
"Hi Attila, To do the job right would be very difficult because, as
you noticed, the envelopes are generated by the code of the 6809
microprocessor. Short of using a faster 6809 (assuming that you could get one) and modifying the code there is not much which can be done.
The Matrix 6 and 12 were designed about 25 years ago, and
microprocessors where a lot slower back then. There is still a bit of hope however. The fastest time for the envelopes is about 2
milliseconds.
This could be reduce to 1 ms by changing RX51 for the VCA (where X
will be 3, 4, 5, 6 or 7 according to which of the six voice it
controls on each of the two voice boards) from 18K to 9.1K.
The next fastest time is set by the microprocessor and an analog
smoothing filter on the voltage control circuit (= Sample and Hold). This time is set not only by the software but also by a resistor RX14 on each of the main voice PCB for the VCA control and by RX10 for the VCF frequency control.
You may want to try reducing these resistors from their original 1 M Ohm value to let say 500K Ohm. This will reduce that time from about 7 ms to about 3.5 ms. The draw back however is that you may get more discontinuity in the shape of the modulation.
The next fastest times however will still be determined by the 6809 software and that will not change. Give it a try on one of the voice and see if that goes toward what you want.
Hope that this helps a bit. Michel Doidic Line 6 CTO"
OK guys, what do you think?
I changed a resistor in my SE-1, and it become snappier (not
fantastic, but better)
Also, the Chroma has a reputaion of very slow envelopes, but same
thing there, if you remove a resistor or change it to a lower value, envelopes supposedly become faster.
I would even go so far to check out the possibilities of putting in a faster processor and find someone to recode the software.
Brainstorming please begin :)
|
Hello takisdamaschis, When you say output capacitors, are you talking about the small 2.2uF Cx49 at the edge of the voice board? There is one for each voice. There is also one of these at the output of each VCO feeding the VCF If these go you can have tuning problems. Also, try resetting the software.( hold sown clear and turn power On) Karl --- In xpantastic@..., "takisdamaschis" <takisdamaschis@...> wrote:
Hi everyone, my xpander seems to fail the VCO tune test randomly!some
voices fail during one test and pass on the next! there is no
cosistancy on the voices that fail,it can be any one of them!Some
times(rarely) the vco test passes! I have the same problem sometimes
with the Resonance and VCF but not as often!
I have totally rebuilt the power supply,changed the battery and output
bypass capacitors!All currents measure right so this is not a voltage
supply problem!
The only other part I can think of is the DAC or maybe the Timer?
Any thoughts?
Takis.
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
Wow, I?m personally not "obsessed" with faster envelopes on my Matrix 12, I rather get reminded of it whenever I play it, don?t need a scope for that. It?s so fxxing great, but would be even greater with faster envelopes IMHO. I have some really fast machines like the P5 and the Minimoog D, so it?s not like I have to get the M12 faster. None of the machines I have are "perfect", in fact I have mods thought out for most of them, but that?s the way I am I guess :) I?m gonna syncmod the Mini next...hope that?s not like cursing in church :) When I have the time, I will start out by change the resistors on one of the voiceboards like Mr Doidic suggested. After all, it worked out on the SE-1. Cheerio --- In xpantastic@..., "Tony Cappellini" <cappy2112@...> wrote:
I personally do not understand this general obsession with making
envelopes faster, the Xpander is perfection itself. It the real
world the basses sound fine, gorgeous in fact, I love them..If you are
actually sitting down with a scope analysing speeds of enevelopes on
these machines, I personally think you've lost it. You need to
actually play it more, write some songs, use it as an instrument.
You change stuff in it, you will ruin the sound I guarantee it.
One does not need a scope to experience the slow envelopes on the
Xpander, it is plainly audible.
The same goes for the OB8.
|
Re: Faster envelopes on Matrix 12/Xpander - Conversation with one of the designers
I personally do not understand this general obsession with making
envelopes faster, the Xpander is perfection itself. It the real world
the basses sound fine, gorgeous in fact, I love them..If you are
actually sitting down with a scope analysing speeds of enevelopes on
these machines, I personally think you've lost it. You need to
actually play it more, write some songs, use it as an instrument. You
change stuff in it, you will ruin the sound I guarantee it.
One does not need a scope to experience the slow envelopes on the Xpander, it is plainly audible. The same goes for the OB8.
|
