OldSynths

Hi all:

I have a Sequential Circuits Pro-One, with the original box and manual.
Unfortunately it does not put out any audio.
It triggers the gate and I get some sort of audio bleed (same frequency
no matter what I do).
Any thoughts on how to go about repair of this unit?

2) I have a Korg Wavestation (original) in nice shape with all the
manuals etc but there is one problem with it:
It plays fine except the octave directly below middle C doesnt work at
all. Is this a octave divider problem, or what?
Anyone who knows this unit please advise- I can solder and swap parts
but dont know what to look for at the moment.

Regards
Rory McDonald
OldSynths Moderator
rorymcd@...

Hmm. hard to say on the sequential...haven't worked on that one. But the
wavestation....there is no 'octave divider' of course. Everything is done
basically in software like that on the WS. I'm not sure how the keyboards
are organized on them but they are the same as the M1 and other korgs that
use basically a DX7 movement from Yamaha. They had a lot of sticking
problems on WS though and I actually took a trashed M1 and swapped in the
keyboard last year finally! Plays a LOT better. Never sticks now. You
were always having to gank keys to keep them from rubbing the lateral
restraints.
Anyway, my guess is there is a scan wire broken on the interconnect
between the two circuit boards that the switch contacts are on, or some
other break in the interconnect, a bent pin or like that. Probably it's
organized so that there is some common wire there. Looking at the
schematic...they only show a sampling of the keys or something and I don't
get
the order of it! Wierd. -Bob

----- Original Message -----
From: "Rory Mc Donald" <rorymcd@...>
To: <oldsynths@yahoogroups.com>
Sent: Wednesday, June 23, 2004 7:32 PM
Subject: [oldsynths] Service question on Sequential Pro-One and WaveStation


> Hi all:
>
> I have a Sequential Circuits Pro-One, with the original box and manual.
> Unfortunately it does not put out any audio.
> It triggers the gate and I get some sort of audio bleed (same frequency
> no matter what I do).
> Any thoughts on how to go about repair of this unit?
>
> 2) I have a Korg Wavestation (original) in nice shape with all the
> manuals etc but there is one problem with it:
> It plays fine except the octave directly below middle C doesnt work at
> all. Is this a octave divider problem, or what?
> Anyone who knows this unit please advise- I can solder and swap parts
> but dont know what to look for at the moment.
>
> Regards
> Rory McDonald
> OldSynths Moderator
> rorymcd@...
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>

At 10:49 AM 6/24/04, you wrote:
Regarding the Pro-One:

First, it helps to narrow down the problem.
No offense, Cory, but are the controls set to produce sound?  (I once had a perfectly functional ProOne brought to me for service that had all the mod switches set to produce zero sound).  Trying out some of the test patches in the manual would eliminate this possibility.

Next, have you checked the output voltages on the back panel jacks (1 volt per octave keyboard control, and positive voltage from the gate out)?

After that, have you tried sending external audio through the filter input jack? It's possible for an oscillator to fail, but rare for BOTH to die at the same time.

Are you willing to open up the unit & test the power supply feeds?  The ProOne requires a heavy +5 load for the digital circuits, and plus & minus 15 volts for the analog.  Any of those missing or out of spec can disable the synth.

Check those things out, & we can go on from there.

~GMM

----- Original Message -----
From: "Rory Mc Donald" <rorymcd@...>
To: <oldsynths@yahoogroups.com>
Sent: Wednesday, June 23, 2004 7:32 PM
Subject: [oldsynths] Service question on Sequential Pro-One and WaveStation


> Hi all:
>
> I have a Sequential Circuits Pro-One, with the original box and manual.
> Unfortunately it does not put out any audio.
> It triggers the gate and I get some sort of audio bleed (same frequency
> no matter what I do).
> Any thoughts on how to go about repair of this unit?
>
> 2) I have a Korg Wavestation (original) in nice shape with all the
> manuals etc but there is one problem with it:
> It plays fine except the octave directly below middle C doesnt work at
> all. Is this a octave divider problem, or what?
> Anyone who knows this unit please advise- I can solder and swap parts
> but dont know what to look for at the moment.
>
> Regards
> Rory McDonald
> OldSynths Moderator
> rorymcd@...
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>
>
>




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Thanks for the input ;)
Yes I checked to make sure it was set to produce sound (I have a number
of modulars) but I will check the output jacks and try the ext IN.
Seems like there is something fundementally wrong with the output,
since I get nothing, but the GATE led lights when keys are pressed.
Also will check the PS feeds too.

Regards
Rory

On Jun 24, 2004, at 11:23 AM, greg montalbano wrote:

> At 10:49 AM 6/24/04, you wrote:
> Regarding the Pro-One:
>
> First, it helps to narrow down the problem.
> No offense, Cory, but are the controls set to produce sound?  (I once
> had a perfectly functional ProOne brought to me for service that had
> all the mod switches set to produce zero sound).  Trying out some of
> the test patches in the manual would eliminate this possibility.
>
> Next, have you checked the output voltages on the back panel jacks (1
> volt per octave keyboard control, and positive voltage from the gate
> out)?
>
> After that, have you tried sending external audio through the filter
> input jack? It's possible for an oscillator to fail, but rare for BOTH
> to die at the same time.
>
> Are you willing to open up the unit & test the power supply feeds? 
> The ProOne requires a heavy +5 load for the digital circuits, and plus
> & minus 15 volts for the analog.  Any of those missing or out of spec
> can disable the synth.
>
> Check those things out, & we can go on from there.
>
> ~GMM
>
>
> ----- Original Message -----
> From: "Rory Mc Donald" <rorymcd@...>
> To: <oldsynths@yahoogroups.com>
> Sent: Wednesday, June 23, 2004 7:32 PM
> Subject: [oldsynths] Service question on Sequential Pro-One and
> WaveStation
>
>
> > Hi all:
> >
> > I have a Sequential Circuits Pro-One, with the original box and
> manual.
> > Unfortunately it does not put out any audio.
> > It triggers the gate and I get some sort of audio bleed (same
> frequency
> > no matter what I do).
> > Any thoughts on how to go about repair of this unit?
> >
> > 2) I have a Korg Wavestation (original) in nice shape with all the
> > manuals etc but there is one problem with it:
> > It plays fine except the octave directly below middle C doesnt work
> at
> > all. Is this a octave divider problem, or what?
> > Anyone who knows this unit please advise- I can solder and swap
> parts
> > but dont know what to look for at the moment.
> >
> > Regards
> > Rory McDonald
> > OldSynths Moderator
> > rorymcd@...
> >
> >
> >
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>
>
>
>
> Yahoo! Groups Sponsor
> ADVERTISEMENT
>
>
> Yahoo! Groups Links
> • To visit your group on the web, go to:
> • http://groups.yahoo.com/group/oldsynths/
> •  
> • To unsubscribe from this group, send an email to:
> • oldsynths-unsubscribe@yahoogroups.com
> •  
> • Your use of Yahoo! Groups is subject to the Yahoo! Terms of
> Service.
>
>
>
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>
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