Vintage Synth Repair

Is there anywhere online that shows how to read schematics for 
synths.  Or am i asking to learn 10 years of worth of education in 10 
minutes?  I'd like to learn how to do basic testing, adjustments and 
repairs.  What kinds of tools do I need?  Do I need any special kind 
of voltmeter or the like?

On Thursday 03 November 2005 09:00 pm, kar_chicago wrote:
> Is there anywhere online that shows how to read schematics for
> synths.  Or am i asking to learn 10 years of worth of education in 10
> minutes?

Reading schematics is pretty basic stuff as far as finding out how things are 
interconnected,  but learning how all that stuff works is another story,  and 
yeah,  it'll take you some nontrivial time...

> I'd like to learn how to do basic testing, adjustments and repairs.  What
> kinds of tools do I need?  Do I need any special kind of voltmeter or the
> like?

At the very least.  And a scope,  and some solid understanding of what you're 
doing...

-- 
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"

Would you mind pointing me to a link where I could find the type of 
scope I need.  Wouldn't want to get the wrong thing.

--- In vintagesynthrepair@yahoogroups.com, "Roy J. Tellason" 
<rtellason@b...> wrote:
>
> On Thursday 03 November 2005 09:00 pm, kar_chicago wrote:
> > Is there anywhere online that shows how to read schematics for
> > synths.  Or am i asking to learn 10 years of worth of education 
in 10
> > minutes?
> 
> Reading schematics is pretty basic stuff as far as finding out how 
things are 
> interconnected,  but learning how all that stuff works is another 
story,  and 
> yeah,  it'll take you some nontrivial time...
> 
> > I'd like to learn how to do basic testing, adjustments and 
repairs.  What
> > kinds of tools do I need?  Do I need any special kind of 
voltmeter or the
> > like?
> 
> At the very least.  And a scope,  and some solid understanding of 
what you're 
> doing...
> 
> -- 
> Member of the toughest, meanest, deadliest, most unrelenting -- and
> ablest -- form of life in this section of space,  a critter that 
can
> be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet 
Masters"
>

Hello:A little advise:A scope that is any good is a big investment 
especially if you don't know how to use one,go to your library or 
electronics parts store and get a book on how to use one first,to start out 
I would recommend a good 4-1/2 digit digital multimeter.and a good set of 
electronics tools,I get by without a scope on about 95% of the repairs I do 
and I work on $60.000+ Digital electronic church organs.
Regards,
Tim K.

direct link to my Ebay store.
http://www.sonicelectronicmusic.com

>From: "kar_chicago" <kar_chicago@...>
>Reply-To: vintagesynthrepair@yahoogroups.com
>To: vintagesynthrepair@yahoogroups.com
>Subject: [vintagesynthrepair] Re: Got the Schematics...now what?
>Date: Fri, 04 Nov 2005 04:36:01 -0000
>
>Would you mind pointing me to a link where I could find the type of
>scope I need.  Wouldn't want to get the wrong thing.
>
>--- In vintagesynthrepair@yahoogroups.com, "Roy J. Tellason"
><rtellason@b...> wrote:
> >
> > On Thursday 03 November 2005 09:00 pm, kar_chicago wrote:
> > > Is there anywhere online that shows how to read schematics for
> > > synths.  Or am i asking to learn 10 years of worth of education
>in 10
> > > minutes?
> >
> > Reading schematics is pretty basic stuff as far as finding out how
>things are
> > interconnected,  but learning how all that stuff works is another
>story,  and
> > yeah,  it'll take you some nontrivial time...
> >
> > > I'd like to learn how to do basic testing, adjustments and
>repairs.  What
> > > kinds of tools do I need?  Do I need any special kind of
>voltmeter or the
> > > like?
> >
> > At the very least.  And a scope,  and some solid understanding of
>what you're
> > doing...
> >
> > --
> > Member of the toughest, meanest, deadliest, most unrelenting -- and
> > ablest -- form of life in this section of space,  a critter that
>can
> > be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet
>Masters"
> >
>
>
>
>
>
>
>
>
>
>Yahoo! Groups Links
>
>
>
>
>
>
>

On Thursday 03 November 2005 11:36 pm, kar_chicago wrote:
> Would you mind pointing me to a link where I could find the type of
> scope I need.  Wouldn't want to get the wrong thing.

There's pretty many that'll do a job for you.  You probably want dual traces 
(more aren't necessary),  and a bandwidth of 20 MHz or better.  Lots of folks 
seem to find them on ebay.  I like Tektronix,  H-P also makes a good one.  
For some stuff a pc-based scope will be good enough.  You might want to 
subscribe to the yahoo Electronics101 group and ask in there...

> --- In vintagesynthrepair@yahoogroups.com, "Roy J. Tellason"
>
> <rtellason@b...> wrote:
> > On Thursday 03 November 2005 09:00 pm, kar_chicago wrote:
> > > Is there anywhere online that shows how to read schematics for
> > > synths.  Or am i asking to learn 10 years of worth of education
>
> in 10
>
> > > minutes?
> >
> > Reading schematics is pretty basic stuff as far as finding out how
>
> things are
>
> > interconnected,  but learning how all that stuff works is another
>
> story,  and
>
> > yeah,  it'll take you some nontrivial time...
> >
> > > I'd like to learn how to do basic testing, adjustments and
>
> repairs.  What
>
> > > kinds of tools do I need?  Do I need any special kind of
>
> voltmeter or the
>
> > > like?
> >
> > At the very least.  And a scope,  and some solid understanding of
>
> what you're
>
> > doing...
> >
> > --
> > Member of the toughest, meanest, deadliest, most unrelenting -- and
> > ablest -- form of life in this section of space,  a critter that
>
> can
>
> > be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet
>
> Masters"
>
>
>
>
>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>

-- 
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"

On Friday 04 November 2005 01:13 am, timothy kosiorek wrote:
> Hello:A little advise:A scope that is any good is a big investment
> especially if you don't know how to use one,go to your library or
> electronics parts store and get a book on how to use one first,to start out
> I would recommend a good 4-1/2 digit digital multimeter.and a good set of
> electronics tools,I get by without a scope on about 95% of the repairs I do
> and I work on $60.000+ Digital electronic church organs.
> Regards,
> Tim K.

Why a 4-1/2 digit meter?  Big jump in price,  there.  I only ever had one item 
of equipment that said that it needed one of those,  one of the earlier Moogs 
as I recall,  and I never did get around to getting one.

> direct link to my Ebay store.
> http://www.sonicelectronicmusic.com
>
>
> From: "kar_chicago" <kar_chicago@...>
>
> >Reply-To: vintagesynthrepair@yahoogroups.com
> >To: vintagesynthrepair@yahoogroups.com
> >Subject: [vintagesynthrepair] Re: Got the Schematics...now what?
> >Date: Fri, 04 Nov 2005 04:36:01 -0000
> >
> >Would you mind pointing me to a link where I could find the type of
> >scope I need.  Wouldn't want to get the wrong thing.
> >
> >--- In vintagesynthrepair@yahoogroups.com, "Roy J. Tellason"
> >
> ><rtellason@b...> wrote:
> > > On Thursday 03 November 2005 09:00 pm, kar_chicago wrote:
> > > > Is there anywhere online that shows how to read schematics for
> > > > synths.  Or am i asking to learn 10 years of worth of education
> >
> >in 10
> >
> > > > minutes?
> > >
> > > Reading schematics is pretty basic stuff as far as finding out how
> >
> >things are
> >
> > > interconnected,  but learning how all that stuff works is another
> >
> >story,  and
> >
> > > yeah,  it'll take you some nontrivial time...
> > >
> > > > I'd like to learn how to do basic testing, adjustments and
> >
> >repairs.  What
> >
> > > > kinds of tools do I need?  Do I need any special kind of
> >
> >voltmeter or the
> >
> > > > like?
> > >
> > > At the very least.  And a scope,  and some solid understanding of
> >
> >what you're
> >
> > > doing...
> > >
> > > --
> > > Member of the toughest, meanest, deadliest, most unrelenting -- and
> > > ablest -- form of life in this section of space,  a critter that
> >
> >can
> >
> > > be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet
> >
> >Masters"
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >Yahoo! Groups Links
>
>
>
> Yahoo! Groups Links
>
>
>

-- 
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"

----- Original Message -----

From: Roy J. Tellason

To: vintagesynthrepair@yahoogroups.com

Sent: Friday, November 04, 2005 7:03 PM

Subject: Re: [vintagesynthrepair] Re: Got the Schematics...now what?

>Why a 4-1/2 digit meter? Big jump in price, there. I only ever had one item
>of equipment that said that it needed one of those, one of the earlier Moogs
>as I recall, and I never did get around to getting one.

Yes, - you´ll need a digit meter w/ an accuracy of 0.1% for adjusting the +10 / -10 volt of a Minimoog PSU for example.

If this is not perfect adjusted,you cannot calibrate a Minis scale, shift, octave and hi-compensation perfect as it will be w/ all the other CV controlled synths of the past.

Meters like this are a good investment if you have to calibrate vintage gear regulary.

PeWe

On Friday 04 November 2005 01:45 pm, pewe wrote:
>   ----- Original Message -----
>   From: Roy J. Tellason
>   To: vintagesynthrepair@yahoogroups.com
>   Sent: Friday, November 04, 2005 7:03 PM
>   Subject: Re: [vintagesynthrepair] Re: Got the Schematics...now what?
>
>   >Why a 4-1/2 digit meter?  Big jump in price,  there.  I only ever had
>   > one item of equipment that said that it needed one of those,  one of
>   > the earlier Moogs as I recall,  and I never did get around to getting
>   > one.
>
>   Yes, - you´ll need a digit meter w/ an accuracy of 0.1% for adjusting the
> +10 / -10 volt of a Minimoog PSU for example. If this is not perfect
> adjusted,you cannot calibrate a Minis scale, shift, octave and
> hi-compensation perfect as it will be w/ all the other CV controlled synths
> of the past.

It wasn't the mini,  which did just fine by me with a 3-1/2 digit meter,  it 
was one of the hybrid ones,  memorymoog maybe?

>   Meters like this are a good investment if you have to calibrate vintage
> gear regulary.

Never found such to be necessary,  and never made the investment,  and I've 
been working on this stuff for decades.

-- 
Member of the toughest, meanest, deadliest, most unrelenting -- and
ablest -- form of life in this section of space,  a critter that can
be killed but can't be tamed.  --Robert A. Heinlein, "The Puppet Masters"

In a message dated 11/4/05 2:29:54 PM, "timothy kosiorek" <tkosiorek@... 
writes:

<<  I would recommend a good 4-1/2 digit digital multimeter.and a good set of 

electronics tools,I get by without a scope on about 95% of the repairs I do  
>>

Tim,

I'll also have to disagree with the 4-1/2 digit multimeter thing.  A 3-1/2 
digit meter is MORE than sufficient for almost anything one might need to do, 
even on most older analog gear.  The cost difference can be quite dramatic, too.

The well-meaning guy that says you need a 4-1/2 digit meter to calibrate a 
Minimoog is just plain wrong.  A $50.00 (or less) 3-1/2 digit meter will work 
perfectly well.  VCO tuning and calibration should *always* be done by ear (with 
the assistance of a good guitar tuner or strobe tuner), and no meter is 
necessary for that.  The Mini's +/-10volt supplies would have to be pretty far off 
to prevent take the VCO's out of tuning range.  Yes, I know that the service 
manual recommends using a 4-1/2 digit meter, but the service manual is simply 
wrong.  Millivolt accuracy is simply not necessary for that calibration.

It's always useful to have an oscilloscope, but as Timothy says, it's not 
absolutely necessary for most repairs.  The multimeter, however, is necessary.

Michael Bacich