Vintage Synth Repair

Hi just wondering if anyone has some advice/tips for me.

I have what appears to be a fully working DR-55 except the drum sounds
are double-triggering. most noticeable is the kick which obviously
flams, making it sound very farty. 

I don't have a scope but i've recorded it to my laptop and can see the
double peak. 

Anyone have any idea what it could be? I can mail relevant service
manual pages if that helps. 

Thanks

Thanks floppy

its definitely not like that - the repeat is about 10ms.

I'm going to try it again at different tempos, see if it alters.



Quoting floppy <floppyscratcher@...>:

> i have the same problem with mine.
> maybe its the start button that sets 2 steps when pressing it once ?
> cause the old beats in memory from the previous owner dont have the 
> doubles...
>
>
>
>
> fr3kkles schrieb:
>>
>> Hi just wondering if anyone has some advice/tips for me.
>>
>> I have what appears to be a fully working DR-55 except the drum sounds
>> are double-triggering. most noticeable is the kick which obviously
>> flams, making it sound very farty.
>>
>> I don't have a scope but i've recorded it to my laptop and can see the
>> double peak.
>>
>> Anyone have any idea what it could be? I can mail relevant service
>> manual pages if that helps.
>>
>> Thanks
>>
>>
>
>

Hi Scott

thanks for your info, and sorry for the HUGE delay in getting back to this.

Its not a start-button problem. regardless of what is programmed in the 
memory, when the cpu [tc5501] sends out the drum trigger signals, its 
like each trigger is doubled. its not a semi-quaver apart but maybe 10ms 
or something, which makes me wonder if the sounds are restarting on the 
falling edge of the trigger pulse as well? but maybe its more basic than 
that..

my knowlege of electronics is very limited - i don't even understand 
what's happening in the clock circuit, maybe the problem is there as it 
connects directly to one of the cpu pins next to the trigger outputs.. ? 
what would happen if C42 was faulty? What does NP 1/50 mean [next to 
C42]. I tried replacing the 4011UB but no change.

Any help very much appreciated

Thanks

Chris

Scott Nordlund wrote:

> I don't have a DR-55 but I downloaded the service manual for my own 
> amusement (I'm cool like that).  I would guess that the note button is 
> double-triggering, and the sequencer then correctly plays back the 
> wrongly-entered sequences (where you can turn the tempo down and hear 
> two successive steps rather than a double-triggered flam), yes?  If 
> I'm understanding this correctly, the rest button shouldn't 
> double-trigger, and you should replace C45.
>
>     ------------------------------------------------------------------------
>     To: vintagesynthrepair@yahoogroups.com
>     From: freckles@...
>     Date: Thu, 10 Apr 2008 18:10:14 +0000
>     Subject: [vintagesynthrepair] Boss DR-55 sounding problem
>
>     Hi just wondering if anyone has some advice/tips for me.
>
>     I have what appears to be a fully working DR-55 except the drum sounds
>     are double-triggering. most noticeable is the kick which obviously
>     flams, making it sound very farty.
>
>     I don't have a scope but i've recorded it to my laptop and can see the
>     double peak.
>
>     Anyone have any idea what it could be? I can mail relevant service
>     manual pages if that helps.
>
>     Thanks
>
>
>
> ------------------------------------------------------------------------
> More immediate than e-mail? Get instant access with Windows Live 
> Messenger. 
> <http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refresh_instantaccess_042008> 
>

I don't have the service manual, but NP 1/50 probably means 1uF 50V non-polar.

2008/10/12 freckles <freckles@...>:
> Hi Scott
>
> thanks for your info, and sorry for the HUGE delay in getting back to this.
>
> Its not a start-button problem. regardless of what is programmed in the
> memory, when the cpu [tc5501] sends out the drum trigger signals, its
> like each trigger is doubled. its not a semi-quaver apart but maybe 10ms
> or something, which makes me wonder if the sounds are restarting on the
> falling edge of the trigger pulse as well? but maybe its more basic than
> that..
>
> my knowlege of electronics is very limited - i don't even understand
> what's happening in the clock circuit, maybe the problem is there as it
> connects directly to one of the cpu pins next to the trigger outputs.. ?
> what would happen if C42 was faulty? What does NP 1/50 mean [next to
> C42]. I tried replacing the 4011UB but no change.
>
> Any help very much appreciated
>
> Thanks
>
> Chris
>
> Scott Nordlund wrote:
>> I don't have a DR-55 but I downloaded the service manual for my own
>> amusement (I'm cool like that).  I would guess that the note button is
>> double-triggering, and the sequencer then correctly plays back the
>> wrongly-entered sequences (where you can turn the tempo down and hear
>> two successive steps rather than a double-triggered flam), yes?  If
>> I'm understanding this correctly, the rest button shouldn't
>> double-trigger, and you should replace C45.
>>
>>     ------------------------------------------------------------------------
>>     To: vintagesynthrepair@yahoogroups.com
>>     From: freckles@freeola.com
>>     Date: Thu, 10 Apr 2008 18:10:14 +0000
>>     Subject: [vintagesynthrepair] Boss DR-55 sounding problem
>>
>>     Hi just wondering if anyone has some advice/tips for me.
>>
>>     I have what appears to be a fully working DR-55 except the drum sounds
>>     are double-triggering. most noticeable is the kick which obviously
>>     flams, making it sound very farty.
>>
>>     I don't have a scope but i've recorded it to my laptop and can see the
>>     double peak.
>>
>>     Anyone have any idea what it could be? I can mail relevant service
>>     manual pages if that helps.
>>
>>     Thanks
>>
>>
>>
>> ------------------------------------------------------------------------
>> More immediate than e-mail? Get instant access with Windows Live
>> Messenger.
>> <http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refresh_instantaccess_042008>
>>
>
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-- 
Antoine Deschênes

There actually isn't a CPU- the TC5501 is a RAM chip (interesting design!).  

I think this would be a very easy problem to solve with an oscilloscope, but things get a little more "interesting" if you don't have one.

Do you hear the "flam" sound on the hi-hat sound?  Do the "16" and "8" modes work properly (8 should be half-speed)?  Do they both have the "flam" sound? 

Do you have a way of observing what comes out of J2?

C42 should determine the tempo, so it's probably fine.

________________________________
To: vintagesynthrepair@yahoogroups.com

From: freckles@...
Date: Sun, 12 Oct 2008 17:23:59 +0100
Subject: Re: [vintagesynthrepair] Boss DR-55 sounding problem - FINALLY!

Hi Scott



thanks for your info, and sorry for the HUGE delay in getting back to this.



Its not a start-button problem. regardless of what is programmed in the

memory, when the cpu [tc5501] sends out the drum trigger signals, its

like each trigger is doubled. its not a semi-quaver apart but maybe 10ms

or something, which makes me wonder if the sounds are restarting on the

falling edge of the trigger pulse as well? but maybe its more basic than

that..



my knowlege of electronics is very limited - i don't even understand

what's happening in the clock circuit, maybe the problem is there as it

connects directly to one of the cpu pins next to the trigger outputs.. ?

what would happen if C42 was faulty? What does NP 1/50 mean [next to

C42]. I tried replacing the 4011UB but no change.



Any help very much appreciated



Thanks



Chris



Scott Nordlund wrote:

> I don't have a DR-55 but I downloaded the service manual for my own

> amusement (I'm cool like that). I would guess that the note button is

> double-triggering, and the sequencer then correctly plays back the

> wrongly-entered sequences (where you can turn the tempo down and hear

> two successive steps rather than a double-triggered flam), yes? If

> I'm understanding this correctly, the rest button shouldn't

> double-trigger, and you should replace C45.

>

> ----------------------------------------------------------

> To: vintagesynthrepair@yahoogroups.com

> From: freckles@freeola.com

> Date: Thu, 10 Apr 2008 18:10:14 +0000

> Subject: [vintagesynthrepair] Boss DR-55 sounding problem

>

> Hi just wondering if anyone has some advice/tips for me.

>

> I have what appears to be a fully working DR-55 except the drum sounds

> are double-triggering. most noticeable is the kick which obviously

> flams, making it sound very farty.

>

> I don't have a scope but i've recorded it to my laptop and can see the

> double peak.

>

> Anyone have any idea what it could be? I can mail relevant service

> manual pages if that helps.

>

> Thanks

>

>

>

> ----------------------------------------------------------

> More immediate than e-mail? Get instant access with Windows Live

> Messenger.

> 

>






















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I have put the DR-55 service manual on my Downloads page at
www.paintingwithsound.co.nz.

--- In vintagesynthrepair@yahoogroups.com, freckles <freckles@...> wrote:
>
> Hi Scott
> 
> thanks for your info, and sorry for the HUGE delay in getting back
to this.
> 
> Its not a start-button problem. regardless of what is programmed in the 
> memory, when the cpu [tc5501] sends out the drum trigger signals, its 
> like each trigger is doubled. its not a semi-quaver apart but maybe
10ms 
> or something, which makes me wonder if the sounds are restarting on the 
> falling edge of the trigger pulse as well? but maybe its more basic
than 
> that..
> 
> my knowlege of electronics is very limited - i don't even understand 
> what's happening in the clock circuit, maybe the problem is there as it 
> connects directly to one of the cpu pins next to the trigger
outputs.. ? 
> what would happen if C42 was faulty? What does NP 1/50 mean [next to 
> C42]. I tried replacing the 4011UB but no change.
> 
> Any help very much appreciated
> 
> Thanks
> 
> Chris
> 
> Scott Nordlund wrote:
> > I don't have a DR-55 but I downloaded the service manual for my own 
> > amusement (I'm cool like that).  I would guess that the note
button is 
> > double-triggering, and the sequencer then correctly plays back the 
> > wrongly-entered sequences (where you can turn the tempo down and hear 
> > two successive steps rather than a double-triggered flam), yes?  If 
> > I'm understanding this correctly, the rest button shouldn't 
> > double-trigger, and you should replace C45.
> >
> >    
------------------------------------------------------------------------
> >     To: vintagesynthrepair@yahoogroups.com
> >     From: freckles@...
> >     Date: Thu, 10 Apr 2008 18:10:14 +0000
> >     Subject: [vintagesynthrepair] Boss DR-55 sounding problem
> >
> >     Hi just wondering if anyone has some advice/tips for me.
> >
> >     I have what appears to be a fully working DR-55 except the
drum sounds
> >     are double-triggering. most noticeable is the kick which obviously
> >     flams, making it sound very farty.
> >
> >     I don't have a scope but i've recorded it to my laptop and can
see the
> >     double peak.
> >
> >     Anyone have any idea what it could be? I can mail relevant service
> >     manual pages if that helps.
> >
> >     Thanks
> >
> >
> >
> >
------------------------------------------------------------------------
> > More immediate than e-mail? Get instant access with Windows Live 
> > Messenger. 
> >
<http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refresh_instantaccess_042008>

> >
>

Oops, how right you are!

I can't hear any flam on the hi-hat, its quite a soft attack on it 
anyway so I might not hear if it was. In the "8" mode the hi-hat lags 
behind by what sounds like a constant amount. At faster tempos it sounds 
ridiculously out of time! Maybe all dr-55s do that - I don't know...

A scope would be better but I suppose I could connect J2 to my 
soundcard, record it and look at the wave. might be wise to go through a 
DI box or something though, don't wanna blow my inputs.


Chris


Scott Nordlund wrote:

> There actually isn't a CPU- the TC5501 is a RAM chip (interesting design!).  
>
> I think this would be a very easy problem to solve with an oscilloscope, but things get a little more "interesting" if you don't have one.
>
> Do you hear the "flam" sound on the hi-hat sound?  Do the "16" and "8" modes work properly (8 should be half-speed)?  Do they both have the "flam" sound? 
>
> Do you have a way of observing what comes out of J2?
>
> C42 should determine the tempo, so it's probably fine.
>
> ________________________________
> To: vintagesynthrepair@yahoogroups.com
> From: freckles@...
> Date: Sun, 12 Oct 2008 17:23:59 +0100
> Subject: Re: [vintagesynthrepair] Boss DR-55 sounding problem - FINALLY!
>
> Hi Scott
>
>
>
> thanks for your info, and sorry for the HUGE delay in getting back to this.
>
>
>
> Its not a start-button problem. regardless of what is programmed in the
>
> memory, when the cpu [tc5501] sends out the drum trigger signals, its
>
> like each trigger is doubled. its not a semi-quaver apart but maybe 10ms
>
> or something, which makes me wonder if the sounds are restarting on the
>
> falling edge of the trigger pulse as well? but maybe its more basic than
>
> that..
>
>
>
> my knowlege of electronics is very limited - i don't even understand
>
> what's happening in the clock circuit, maybe the problem is there as it
>
> connects directly to one of the cpu pins next to the trigger outputs.. ?
>
> what would happen if C42 was faulty? What does NP 1/50 mean [next to
>
> C42]. I tried replacing the 4011UB but no change.
>
>
>
> Any help very much appreciated
>
>
>
> Thanks
>
>
>
> Chris
>
>
>
> Scott Nordlund wrote:
>
>   
>> I don't have a DR-55 but I downloaded the service manual for my own
>>     
>
>   
>> amusement (I'm cool like that). I would guess that the note button is
>>     
>
>   
>> double-triggering, and the sequencer then correctly plays back the
>>     
>
>   
>> wrongly-entered sequences (where you can turn the tempo down and hear
>>     
>
>   
>> two successive steps rather than a double-triggered flam), yes? If
>>     
>
>   
>> I'm understanding this correctly, the rest button shouldn't
>>     
>
>   
>> double-trigger, and you should replace C45.
>>     
>
>   
>
>   
>> ----------------------------------------------------------
>>     
>
>   
>> To: vintagesynthrepair@yahoogroups.com
>>     
>
>   
>> From: freckles@...
>>     
>
>   
>> Date: Thu, 10 Apr 2008 18:10:14 +0000
>>     
>
>   
>> Subject: [vintagesynthrepair] Boss DR-55 sounding problem
>>     
>
>   
>
>   
>> Hi just wondering if anyone has some advice/tips for me.
>>     
>
>   
>
>   
>> I have what appears to be a fully working DR-55 except the drum sounds
>>     
>
>   
>> are double-triggering. most noticeable is the kick which obviously
>>     
>
>   
>> flams, making it sound very farty.
>>     
>
>   
>
>   
>> I don't have a scope but i've recorded it to my laptop and can see the
>>     
>
>   
>> double peak.
>>     
>
>   
>
>   
>> Anyone have any idea what it could be? I can mail relevant service
>>     
>
>   
>> manual pages if that helps.
>>     
>
>   
>
>   
>> Thanks
>>     
>
>   
>
>   
>
>   
>
>   
>> ----------------------------------------------------------
>>     
>
>   
>> More immediate than e-mail? Get instant access with Windows Live
>>     
>
>   
>> Messenger.
>>     
>
>   
>
>   
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> _________________________________________________________________
> See how Windows Mobile brings your life together\ufffdat home, work, or on the go.
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I already found it somewhere, but thanks for the thought man.

chris

paintingwithsound wrote:

> I have put the DR-55 service manual on my Downloads page at
> www.paintingwithsound.co.nz.
>
> --- In vintagesynthrepair@yahoogroups.com, freckles <freckles@...> wrote:
>   
>> Hi Scott
>>
>> thanks for your info, and sorry for the HUGE delay in getting back
>>     
> to this.
>   
>> Its not a start-button problem. regardless of what is programmed in the 
>> memory, when the cpu [tc5501] sends out the drum trigger signals, its 
>> like each trigger is doubled. its not a semi-quaver apart but maybe
>>     
> 10ms 
>   
>> or something, which makes me wonder if the sounds are restarting on the 
>> falling edge of the trigger pulse as well? but maybe its more basic
>>     
> than 
>   
>> that..
>>
>> my knowlege of electronics is very limited - i don't even understand 
>> what's happening in the clock circuit, maybe the problem is there as it 
>> connects directly to one of the cpu pins next to the trigger
>>     
> outputs.. ? 
>   
>> what would happen if C42 was faulty? What does NP 1/50 mean [next to 
>> C42]. I tried replacing the 4011UB but no change.
>>
>> Any help very much appreciated
>>
>> Thanks
>>
>> Chris
>>
>> Scott Nordlund wrote:
>>     
>>> I don't have a DR-55 but I downloaded the service manual for my own 
>>> amusement (I'm cool like that).  I would guess that the note
>>>       
> button is 
>   
>>> double-triggering, and the sequencer then correctly plays back the 
>>> wrongly-entered sequences (where you can turn the tempo down and hear 
>>> two successive steps rather than a double-triggered flam), yes?  If 
>>> I'm understanding this correctly, the rest button shouldn't 
>>> double-trigger, and you should replace C45.
>>>
>>>    
>>>       
> ------------------------------------------------------------------------
>   
>>>     To: vintagesynthrepair@yahoogroups.com
>>>     From: freckles@...
>>>     Date: Thu, 10 Apr 2008 18:10:14 +0000
>>>     Subject: [vintagesynthrepair] Boss DR-55 sounding problem
>>>
>>>     Hi just wondering if anyone has some advice/tips for me.
>>>
>>>     I have what appears to be a fully working DR-55 except the
>>>       
> drum sounds
>   
>>>     are double-triggering. most noticeable is the kick which obviously
>>>     flams, making it sound very farty.
>>>
>>>     I don't have a scope but i've recorded it to my laptop and can
>>>       
> see the
>   
>>>     double peak.
>>>
>>>     Anyone have any idea what it could be? I can mail relevant service
>>>     manual pages if that helps.
>>>
>>>     Thanks
>>>
>>>
>>>
>>>
>>>       
> ------------------------------------------------------------------------
>   
>>> More immediate than e-mail? Get instant access with Windows Live 
>>> Messenger. 
>>>
>>>       
> <http://www.windowslive.com/messenger/overview.html?ocid=TXT_TAGLM_WL_Refresh_instantaccess_042008>
>
>   
>
>
>
> ------------------------------------
>
> Yahoo! Groups Links
>
>
>
>
>

I doubt J2's output would damage anything, but you could use some sort of gain stage (pre-amp or something?) before your soundcard if you're worried.  Pulses should be about 10 ms long, which you should be able to measure on your computer.

> To: vintagesynthrepair@yahoogroups.com
> From: freckles@freeola.com
> Date: Mon, 13 Oct 2008 15:00:59 +0100
> Subject: Re: [vintagesynthrepair] Boss DR-55 sounding problem - FINALLY!
>
> Oops, how right you are!
>
> I can't hear any flam on the hi-hat, its quite a soft attack on it
> anyway so I might not hear if it was. In the "8" mode the hi-hat lags
> behind by what sounds like a constant amount. At faster tempos it sounds
> ridiculously out of time! Maybe all dr-55s do that - I don't know...
>
> A scope would be better but I suppose I could connect J2 to my
> soundcard, record it and look at the wave. might be wise to go through a
> DI box or something though, don't wanna blow my inputs.
>
>
> Chris
>
>
> Scott Nordlund wrote:
>> There actually isn't a CPU- the TC5501 is a RAM chip (interesting design!).
>>
>> I think this would be a very easy problem to solve with an oscilloscope, but things get a little more "interesting" if you don't have one.
>>
>> Do you hear the "flam" sound on the hi-hat sound? Do the "16" and "8" modes work properly (8 should be half-speed)? Do they both have the "flam" sound?
>>
>> Do you have a way of observing what comes out of J2?
>>
>> C42 should determine the tempo, so it's probably fine.
>>
>> ________________________________
>> To: vintagesynthrepair@yahoogroups.com
>> From: freckles@...
>> Date: Sun, 12 Oct 2008 17:23:59 +0100
>> Subject: Re: [vintagesynthrepair] Boss DR-55 sounding problem - FINALLY!
>>
>> Hi Scott
>>
>>
>>
>> thanks for your info, and sorry for the HUGE delay in getting back to this.
>>
>>
>>
>> Its not a start-button problem. regardless of what is programmed in the
>>
>> memory, when the cpu [tc5501] sends out the drum trigger signals, its
>>
>> like each trigger is doubled. its not a semi-quaver apart but maybe 10ms
>>
>> or something, which makes me wonder if the sounds are restarting on the
>>
>> falling edge of the trigger pulse as well? but maybe its more basic than
>>
>> that..
>>
>>
>>
>> my knowlege of electronics is very limited - i don't even understand
>>
>> what's happening in the clock circuit, maybe the problem is there as it
>>
>> connects directly to one of the cpu pins next to the trigger outputs.. ?
>>
>> what would happen if C42 was faulty? What does NP 1/50 mean [next to
>>
>> C42]. I tried replacing the 4011UB but no change.
>>
>>
>>
>> Any help very much appreciated
>>
>>
>>
>> Thanks
>>
>>
>>
>> Chris
>>
>>
>>
>> Scott Nordlund wrote:
>>
>>
>>> I don't have a DR-55 but I downloaded the service manual for my own
>>>
>>
>>
>>> amusement (I'm cool like that). I would guess that the note button is
>>>
>>
>>
>>> double-triggering, and the sequencer then correctly plays back the
>>>
>>
>>
>>> wrongly-entered sequences (where you can turn the tempo down and hear
>>>
>>
>>
>>> two successive steps rather than a double-triggered flam), yes? If
>>>
>>
>>
>>> I'm understanding this correctly, the rest button shouldn't
>>>
>>
>>
>>> double-trigger, and you should replace C45.
>>>
>>
>>
>>
>>
>>> ----------------------------------------------------------
>>>
>>
>>
>>> To: vintagesynthrepair@yahoogroups.com
>>>
>>
>>
>>> From: freckles@...
>>>
>>
>>
>>> Date: Thu, 10 Apr 2008 18:10:14 +0000
>>>
>>
>>
>>> Subject: [vintagesynthrepair] Boss DR-55 sounding problem
>>>
>>
>>
>>
>>
>>> Hi just wondering if anyone has some advice/tips for me.
>>>
>>
>>
>>
>>
>>> I have what appears to be a fully working DR-55 except the drum sounds
>>>
>>
>>
>>> are double-triggering. most noticeable is the kick which obviously
>>>
>>
>>
>>> flams, making it sound very farty.
>>>
>>
>>
>>
>>
>>> I don't have a scope but i've recorded it to my laptop and can see the
>>>
>>
>>
>>> double peak.
>>>
>>
>>
>>
>>
>>> Anyone have any idea what it could be? I can mail relevant service
>>>
>>
>>
>>> manual pages if that helps.
>>>
>>
>>
>>
>>
>>> Thanks
>>>
>>
>>
>>
>>
>>
>>
>>
>>
>>> ----------------------------------------------------------
>>>
>>
>>
>>> More immediate than e-mail? Get instant access with Windows Live
>>>
>>
>>
>>> Messenger.
>>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> _________________________________________________________________
>> See how Windows Mobile brings your life together—at home, work, or on the go.
>> http://clk.atdmt.com/MRT/go/msnnkwxp1020093182mrt/direct/01/
>> ------------------------------------
>>
>> Yahoo! Groups Links
>>
>>
>>
>>
>>
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--- In vintagesynthrepair@yahoogroups.com, Scott Nordlund <gsn10@...> 
wrote:

> A friend's Ibanez DM1000 digital delay has a tone pot marked "50K G", 
where the others are labeled "10K A", etc. to indicate the taper.  The 

I don't want to sound defeatist, but even if you knew what it was,
you're not likely to find a replacement.

I'd put a linear one in, then add tapering resistors "according
to taste". Ask your friend to try it out and see what he thinks.
If he says it cramped at the top, make it a bit more loggy, and
vice-versa.

Cheers

mark-r

> > A friend's Ibanez DM1000 digital delay has a tone pot marked "50K  
> G",
> where the others are labeled "10K A", etc. to indicate the taper.
>

Are you sure it is not "C"?
Which would indicate reverse log taper.


Terje Winther
terje.winther@...
http://www.wintherstormer.no/

This is definitely G, it's indicated on both the pot and the circuit board.

I'll probably just try a linear pot and see how that works.

________________________________
To: vintagesynthrepair@yahoogroups.com

From: terje.winther@...
Date: Sat, 18 Oct 2008 15:20:45 +0200
Subject: Re: [vintagesynthrepair] Re: unusual pot marking- G?

> A friend's Ibanez DM1000 digital delay has a tone pot marked "50K G",
where the others are labeled "10K A", etc. to indicate the taper.

Are you sure it is not "C"?
Which would indicate reverse log taper.


Terje Winther
terje.winther@wintherstormer.no
http://www.wintherstormer.no/
_________________________________________________________________
When your life is on the go—take your life with you.
http://clk.atdmt.com/MRT/go/115298558/direct/01/

weird problem. i have a DK 600 too and it doesn't really work at all.
i turn it on and can sometimes get the first lfo's led to flash and
one of the digits on the display to light up, but that's it. i've been
shotgunning ICs on the board underneath the keyboard and somewhere in
there i got the other digit on the display working and i even got a
couple of the voice chip LEDs to light, but now it's back to normal.
any thoughts? (i replaced the battery too, though i don't think it was
leaky)

thanks,
johnny

--- In vintagesynthrepair@yahoogroups.com, Scott Nordlund <gsn10@...>
wrote:
>
> 
> I repaired the NiCd battery corrosion problem in my Siel DK 600 (and
also the Expander module), then attempted to address a CV demux/sample
and hold problem (envelope release time was too short because a
defective component was draining the charge from the capacitor).  I
replaced the associated parts (4051 and TL084), and it fixed the
problem, but also introduced some new ones.  The CVs associated with
these chips (filter cutoff, oscillator detune, etc.) are unstable when
the synth is first switched on, and will actually change (in an
interesting way) when there's some kind of mechanical vibration.  It
mostly resolves after the synth has had a few minutes to warm up.  I
do appreciate the added "vintage driftiness" and "innovative
performance controls", but I'd really rather have it do what I want it
to do.  I've tried reseating the chips.
> 
> It won't be a big deal to just rework the whole thing by replacing
all the parts (sockets included) and then thoroughly cleaning off the
flux, but the crappy DIP connectors seem to have a very limited
lifespan and I don't really want to go plugging and unplugging any
more than absolutely necessary.  I'd like to fix it and be done with
it.  I'll redily admit that using salvaged components (sockets even)
probably isn't the best idea, but I'm too cheap and lazy to order
parts, and it's probably not any more likely to cause problems than
the original flaky construction.
> 
> So based on this, is the problem more likely to be a bad solder
joint or bad socket, or is the solder flux on the board interfering
with the high impedance stuff?  I'd guess the former, but again I
don't want to risk breaking a pin on a DIP connector if I have to
rework it again.
> 
> There's also some sort of interference that seems to affect the
pulsewidth and cutoff CVs (?) of voices 5 and 6.  I probably won't be
able to address this without an oscilloscope, but it's not extremely
intrusive, so it can wait (though I'm also open to suggestions here!).
> 
> _________________________________________________________________
> Windows Live Hotmail now works up to 70% faster.
>
http://windowslive.com/Explore/Hotmail?ocid=TXT_TAGLM_WL_hotmail_acq_faster_112008
>

--- In vintagesynthrepair@yahoogroups.com, Scott Nordlund <gsn10@...>
wrote:
>
> 
> You'll have to go at it with a scope or logic tester or something
and see what's working and what isn't.  There are a bunch of latches
on the data bus that route signals from the CPU to various locations,
controlled by IC8 (port decoder).  I had a couple problems in this
region due to broken/corroded traces, so it may be a good place to
start.  Really, these things are so delicate and poorly-made that
there's not really any single point of failure (how many could
possibly still be in operation?), you have to figure it out on your own.
> 
> To: vintagesynthrepair@yahoogroups.com
> From: cockandswan@...
> Date: Tue, 23 Dec 2008 17:58:26 +0000
> Subject: [vintagesynthrepair] Re: Siel DK 600, strange problem
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
>     
>             weird problem. i have a DK 600 too and it doesn't really
work at all.
> 
> i turn it on and can sometimes get the first lfo's led to flash and
> 
> one of the digits on the display to light up, but that's it. i've been
> 
> shotgunning ICs on the board underneath the keyboard and somewhere in
> 
> there i got the other digit on the display working and i even got a
> 
> couple of the voice chip LEDs to light, but now it's back to normal.
> 
> any thoughts? (i replaced the battery too, though i don't think it was
> 
> leaky)
> 
> 
> 
> thanks,
> 
> johnny
> 
> 
> 
> --- In vintagesynthrepair@yahoogroups.com, Scott Nordlund <gsn10@>
> 
> wrote:
> 
> >
> 
> > 
> 
> > I repaired the NiCd battery corrosion problem in my Siel DK 600 (and
> 
> also the Expander module), then attempted to address a CV demux/sample
> 
> and hold problem (envelope release time was too short because a
> 
> defective component was draining the charge from the capacitor).  I
> 
> replaced the associated parts (4051 and TL084), and it fixed the
> 
> problem, but also introduced some new ones.  The CVs associated with
> 
> these chips (filter cutoff, oscillator detune, etc.) are unstable when
> 
> the synth is first switched on, and will actually change (in an
> 
> interesting way) when there's some kind of mechanical vibration.  It
> 
> mostly resolves after the synth has had a few minutes to warm up.  I
> 
> do appreciate the added "vintage driftiness" and "innovative
> 
> performance controls", but I'd really rather have it do what I want it
> 
> to do.  I've tried reseating the chips.
> 
> > 
> 
> > It won't be a big deal to just rework the whole thing by replacing
> 
> all the parts (sockets included) and then thoroughly cleaning off the
> 
> flux, but the crappy DIP connectors seem to have a very limited
> 
> lifespan and I don't really want to go plugging and unplugging any
> 
> more than absolutely necessary.  I'd like to fix it and be done with
> 
> it.  I'll redily admit that using salvaged components (sockets even)
> 
> probably isn't the best idea, but I'm too cheap and lazy to order
> 
> parts, and it's probably not any more likely to cause problems than
> 
> the original flaky construction.
> 
> > 
> 
> > So based on this, is the problem more likely to be a bad solder
> 
> joint or bad socket, or is the solder flux on the board interfering
> 
> with the high impedance stuff?  I'd guess the former, but again I
> 
> don't want to risk breaking a pin on a DIP connector if I have to
> 
> rework it again.
> 
> > 
> 
> > There's also some sort of interference that seems to affect the
> 
> pulsewidth and cutoff CVs (?) of voices 5 and 6.  I probably won't be
> 
> able to address this without an oscilloscope, but it's not extremely
> 
> intrusive, so it can wait (though I'm also open to suggestions here!).
> 
> > 
> 
> > __________________________________________________________
> 
I had a customers unit in here at the shop.
Same issues. The battery had leaked on the main board.
I would say that anywhere you see bluish tint on the board , that's
where some of the battery leakage went. This problem will require
running jumper wires anywhere that the leakage showed up.
Check power supply lines coming into the main board too.
and the encoder that was mentioned by someone else.

Leaking batterys are the Horror show of vintage synths with memory

> 
> 
> 
> 
>       
> 
>     
>     
> 	
> 	
> 	
> 	
> 
> 
> 	
> 
> 
> 	
> 	
> _________________________________________________________________
>