Thanks, I will try replacing the capacitor first. Hopefully that will be the cause of the
problem.

ktfiz

Your very welcome, Jeff

Karl


--- In xpantastic@..., vco3@... wrote:

HI thanks karl. it worked. I replaced all the 2.2 caps in that

voice and it

tunes fine now.. thanks jeff

Hi ktfiz,

Lets hope it's not the AD7523. This part is rare anymore.I would bet
it's the bypass capacitor Cx02. Where x is 2,3,4,5,6,7 depending on
the voice number. It's a 2.2 uF @ 50 V electrolytic capacitor. We
have seen the same value cap fail alot lately in expander/M12.
Best Regards
Karl




--- In xpantastic@..., "ktfiz" <k.tomasson@...> wrote:

Hi,

One voice on my Xpander does not seem to respond to the addition of

FM, otherwise it

functions and sounds fine. All six voices pass all the self tests.

From the service notes, it looks like FM is handled by an AD7523

IC. Anyone know if this is

the culprit?

Thanks.

Hi,

One voice on my Xpander does not seem to respond to the addition of FM, otherwise it
functions and sounds fine. All six voices pass all the self tests.

From the service notes, it looks like FM is handled by an AD7523 IC. Anyone know if this is
the culprit?

Thanks.

Hi Takis,

What does the your voltmeter read when you measure the zener(D805)?
I keep thinking it's something to do with this circuit.
I am going to open mine up and see what I get.

Karl



--- In xpantastic@..., "takisdamaschis"
<takisdamaschis@...> wrote:

--- In xpantastic@..., "Karl" <shire03@> wrote:

Hi Karl,
done everything you pointed out,no improvements!
Anything else you can think of before we go for the DAC?
Thanks,Takis.

Hi Takis,

I also noticed that I get 3.79V at one of the pins of U815

instead

of 4.0V(+/- .05V) as the service manual points out!

Okay, lets look at D805, A zener diode which provides the

reference

for the DAC.Measure this with a good voltmeter, it should be

6.9V.

Again, try reflowing the solder around this part and the ref

circuit.

If you have a service
manual, Look at the circuit around U815 and reflow all the solder
around this part and the resistors capacitors etc...
Try this and let me know.

Karl



--- In xpantastic@..., "takisdamaschis"
<takisdamaschis@> wrote:

Hi Karl,
I have gone and replaced all parts you suggested, re-seated the

dac

and went over all solders!
No improvement, I keep getting the same problem!
I also noticed that I get 3.79V at one of the pins of U815

instead

of

4.0V(+/- .05V) as the service manual points out!
Anyway the good news is that I found a NOS dac ($150) which I

will

try

out as soon as it gets in(in a few days I hope).
I'll let you know!
Thanks,Takis.


--- 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.

--- In xpantastic@..., vco3@... wrote:

HI, I just started getting a failed PW message on voice three on

the

xpander. THe voice still sounds fine when I reenable it. IT is just

a little

quieter.. I went thru a swapped all ics with the next voice over

and the problem

still is on voice threee.. Any ideas of what it could be? thanks

analoguejeff

Hi Jeff,

If you feel good about working on your synth/soldering etc. I beleive
this is an easy fix. There are two bypass capacitors which each VCO
voice signal goes through before going to the VCF. The Value is
2.2uF @ 50VDC.
the part number for voice 3 is C533 and C537. They are located about
1/3 of the way up the cicuit board. If these fail they tend to block
the signal out causing lower output and tuning fails. If this does
not fix it, replace C549 also a 2.2 uF 50 V electrolytic cap towards
the bottom of the board. You may already know this but, these are
electrolytic caps(look like little cans on the circuit board) They
are polarity sensitive, so you can put them in backwards. There
should be a minus ( - ) sign on one side to show correct orientation.

Best of luck

Karl

开云体育

Yes, a pedal in general is just a pot you move w/ your foot,- but this not only for "volume" ...

Manual says clearly: Pedal inputs for PEDALS or FOOTSWITCHES.

All common momentary switches work as expected if the polarity is right.
A PEDAL works like a LEVER ( of a Matrix12 p.ex. and a LEVER is a pot )
If it works or not depends on the pedal or pot used.
You cannot use any pedal.

Lever 1 and Pedal 1 exist independently for each voice, Lever 2 and Pedal 2 are universal controllers,- this does not depend on midi in any way.

Jeremy Smith schrieb:

开云体育

Sorry, but I have connected a momentary ft.-switch AND a Oberheim OBX-P pedal ( not switch ) at my Xpander here.

There are differences between "Pedal Inputs" #1 + #2,- both work like Levers 1 + 2 but Pedal #2 and Lever 2 are universal controllers while Pedal #1 and Lever 1 are existing independently and in each voice.

If I defeat midi for the pedal input 1 w/ the Oberheim pedal connected and route pedal 1 as modulation source to the filters cutoff frequency, this is modulated by the pedal continuously because it?s a pedal and not a open/close switch.

The Oberheim pedal acts like a lever in this case and because it?s "Pedal #1", also relatively to each voice.

A Lever is also only a pot and doesn?t behave like a on/off switch.

Seems, you guys have the wrong pedals, - that?s all.


Tony Cappellini schrieb:

PeWe wrote:

Hi Tony !

It?s possible to connect momentary switches as also pedals w/ a pot
inside to the Xpander.
A Moog CV-pedal Modell 1120 p.ex. or a Oberheim OBX-P pedal.
Both, switches or pedals, need to have standard 1/4" TS phones
connectors,- but not (stereo) TRS ones.

Momentary switches and pedals can be routed as modulation sources
Pedal #1 / Pedal #2 to any modulation destination like VCAs, Filter
cutoff, resonance and so on.

There is a selection of standard midi controllers available in the
midi page, assigning controllers like CC#07 (volume) or others to the
pedals in addition, - but that doesn?t mean the pedals transmit these
controllers, - it?s just the _virtual_ "pedal inputs" which receive
midi controllers, being routed as "Pedal #1" and "Pedal #2" to the
modulation destinations.

Example:
No dedicated Pedals connected to the Xpander and "Pedal #1" in the
midi page set to "volume CC#07",- means:

Any received CC#7 midi data is routed to pedal #1 and is only active
if pedal #1 is being set up in a patch to modulate p.ex. VCA 2,-
result = volume control by a midi controller.

No midi input, but physical pedal #1 being connected to pedal#1 input
and routed to modulated VCA2,- result= volume control via the physical
pedal ( not by midi).

hope that?s clear now ...

PeWe


Tony Cappellini schrieb:

But will it work in Pedal Input 1 & 2 in my Xpander? I'm confused. How
can a MIDI controller be a 1/4" jack, and how the heck can it be in

stereo?

You would have to assign Pedal 1/2 to a CC#.
But I believe pedal 1/2 are intended to be used as on/off switches,
not sources that can vary a signal, as in a volume pedal.
I may be wrong.

If your pedal has a pot in it, try assigning it to CC7 in the xpander
and assign that to a VCA, see if your volume changes.

Ah, I think I understand. Thanks for the answers!

The pedal is just a pot, a volume control (up/down).

It looks like I'll have to get a PC-200 MKII controller with a pot pedal
socket. I used to have one but it broke so I got a MK 1 and it's not as
good. With this I should be able to mess around with the Xpander's
filter by pedal. :-)

Jeremy.

It?s possible to connect momentary switches as also pedals w/ a pot inside to the Xpander.

Momentary switches and pedals can be routed as modulation sources Pedal #1 / Pedal #2 to any modulation destination like VCAs, >Filter cutoff, resonance and so on.

Yes- but these will only provide on/off type of modulation, not a
smooth transition between a min and max value, like a pot would.
Perhaps you could smooth out the threshold between the on/off using
the Tracking Gens.

pedals in addition, - but that doesn?t mean the pedals transmit these controllers,

Of course not, not if it has a 1/4 inch jack on it. It's just a pot,
or an open/closed switch, no midi.

开云体育

Hi Tony !

It?s possible to connect momentary switches as also pedals w/ a pot inside to the Xpander.
A Moog CV-pedal Modell 1120 p.ex. or a Oberheim OBX-P pedal.
Both, switches or pedals, need to have standard 1/4" TS phones connectors,- but not (stereo) TRS ones.

Momentary switches and pedals can be routed as modulation sources Pedal #1 / Pedal #2 to any modulation destination like VCAs, Filter cutoff, resonance and so on.

There is a selection of standard midi controllers available in the midi page, assigning controllers like CC#07 (volume) or others to the pedals in addition, - but that doesn?t mean the pedals transmit these controllers, - it?s just the virtual "pedal inputs" which receive midi controllers, being routed as "Pedal #1" and "Pedal #2" to the modulation destinations.

Example:
No dedicated Pedals connected to the Xpander and "Pedal #1" in the midi page set to "volume CC#07",- means:

Any received CC#7 midi data is routed to pedal #1 and is only active if pedal #1 is being set up in a patch to modulate p.ex. VCA 2,- result = volume control by a midi controller.

No midi input, but physical pedal #1 being connected to pedal#1 input and routed to modulated VCA2,- result= volume control via the physical pedal ( not by midi).

hope that?s clear now ...

PeWe


Tony Cappellini schrieb:

But will it work in Pedal Input 1 & 2 in my Xpander? I'm confused. How
can a MIDI controller be a 1/4" jack, and how the heck can it be in stereo?

You would have to assign Pedal 1/2 to a CC#.
But I believe pedal 1/2 are intended to be used as on/off switches,
not sources that can vary a signal, as in a volume pedal.
I may be wrong.

If your pedal has a pot in it, try assigning it to CC7 in the xpander
and assign that to a VCA, see if your volume changes.

Hi folks,

I recently bought a stereo volume pedal with a stereo 1/4" jack on it, and it's not working with the Crumar Toccata I have.

But will it work in Pedal Input 1 & 2 in my Xpander? I'm confused. How can a MIDI controller be a 1/4" jack, and how the heck can it be in stereo?

Also, are the pedals unique to Roland, Korg, etc, or is it the same standard?

I've tried looking online but no dice.

Thanks for any advice,

Jeremy.

--- In xpantastic@..., "Karl" <shire03@...> wrote:

Hi Karl,
done everything you pointed out,no improvements!
Anything else you can think of before we go for the DAC?
Thanks,Takis.

Hi Takis,

I also noticed that I get 3.79V at one of the pins of U815 instead
of 4.0V(+/- .05V) as the service manual points out!

Okay, lets look at D805, A zener diode which provides the reference
for the DAC.Measure this with a good voltmeter, it should be 6.9V.
Again, try reflowing the solder around this part and the ref circuit.
If you have a service
manual, Look at the circuit around U815 and reflow all the solder
around this part and the resistors capacitors etc...
Try this and let me know.

Karl



--- In xpantastic@..., "takisdamaschis"
<takisdamaschis@> wrote:

Hi Karl,
I have gone and replaced all parts you suggested, re-seated the dac
and went over all solders!
No improvement, I keep getting the same problem!
I also noticed that I get 3.79V at one of the pins of U815 instead

of

4.0V(+/- .05V) as the service manual points out!
Anyway the good news is that I found a NOS dac ($150) which I will

try

out as soon as it gets in(in a few days I hope).
I'll let you know!
Thanks,Takis.


--- 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.

Almost forgot.

MIDI enables: SYSTEMX XMITCV PATCH all On

Jeremy.

Hi all,

I just wanted to share that I tried Soundquest 10 again for editing my Xpander and it worked!

One useful trick is you crank up VCA2 so the note plays all the time, and edits then are audible/updated without having to hit F10.

Editing now and making a great chorus organ sound!

Jeremy.

Hi Takis,

I also noticed that I get 3.79V at one of the pins of U815 instead
of 4.0V(+/- .05V) as the service manual points out!

Okay, lets look at D805, A zener diode which provides the reference
for the DAC.Measure this with a good voltmeter, it should be 6.9V.
Again, try reflowing the solder around this part and the ref circuit.
If you have a service
manual, Look at the circuit around U815 and reflow all the solder
around this part and the resistors capacitors etc...
Try this and let me know.

Karl



--- In xpantastic@..., "takisdamaschis"
<takisdamaschis@...> wrote:

Hi Karl,
I have gone and replaced all parts you suggested, re-seated the dac
and went over all solders!
No improvement, I keep getting the same problem!
I also noticed that I get 3.79V at one of the pins of U815 instead

of

4.0V(+/- .05V) as the service manual points out!
Anyway the good news is that I found a NOS dac ($150) which I will

try

out as soon as it gets in(in a few days I hope).
I'll let you know!
Thanks,Takis.


--- 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.