Vintage Synth Repair

I've had the SRM service notes for years but has anyone got schenatics for the earlier builds? I have a Rev A in front of me here and could use the schems for it. Gotta hand it to Octave though. Each IC is already socketed! Nice.

Quick update. The PCB says Rev A but I don't see those SSMs anywhere. This appears to contradict some old thread on the versions that exist. ?



--- In vintagesynthrepair@yahoogroups.com, "Boddington" <f115@...> wrote:

>
> I've had the SRM service notes for years but has anyone got schenatics for the earlier builds? I have a Rev A in front of me here and could use the schems for it. Gotta hand it to Octave though. Each IC is already socketed! Nice.
>

Rev A Cats had no SSMs, only the SRM (SSM2040) and SRM II (SSM2044). I have never seen the SRM service manual, only the original and SRM II. Are you sure you have the SRM service manual? That would be great to scan it for everyone if you do.

Doug 
synthparts.com
--- In vintagesynthrepair@yahoogroups.com, "Boddington" <f115@...> wrote:

>
> Quick update. The PCB says Rev A but I don't see those SSMs anywhere. This appears to contradict some old thread on the versions that exist. ?
> 
> 
> 
> --- In vintagesynthrepair@yahoogroups.com, "Boddington" <f115@> wrote:
> >
> > I've had the SRM service notes for years but has anyone got schenatics for the earlier builds? I have a Rev A in front of me here and could use the schems for it. Gotta hand it to Octave though. Each IC is already socketed! Nice.
> >
>

Actually it's the SRM II service manual that I've never found. Anyoen have it? I have the original Cat and SRM... 

Doug 
synthparts.com

--- In vintagesynthrepair@yahoogroups.com, "synthparts" <synthparts@...> wrote:

>
> Rev A Cats had no SSMs, only the SRM (SSM2040) and SRM II (SSM2044). I have never seen the SRM service manual, only the original and SRM II. Are you sure you have the SRM service manual? That would be great to scan it for everyone if you do.
> 
> Doug 
> synthparts.com
> --- In vintagesynthrepair@yahoogroups.com, "Boddington" <f115@> wrote:
> >
> > Quick update. The PCB says Rev A but I don't see those SSMs anywhere. This appears to contradict some old thread on the versions that exist. ?
> > 
> > 
> > 
> > --- In vintagesynthrepair@yahoogroups.com, "Boddington" <f115@> wrote:
> > >
> > > I've had the SRM service notes for years but has anyone got schenatics for the earlier builds? I have a Rev A in front of me here and could use the schems for it. Gotta hand it to Octave though. Each IC is already socketed! Nice.
> > >
> >
>

Elektrotanya.com has the Octave Cat service manual with schematics.

On 3/13/2013 21:46, synthparts wrote:
> Actually it's the SRM II service manual that I've never found. Anyoen
> have it? I have the original Cat and SRM...
>
> Doug
> synthparts.com
>
> --- In vintagesynthrepair@yahoogroups.com
> <mailto:vintagesynthrepair%40yahoogroups.com>, "synthparts"
> <synthparts@...> wrote:
>  >
>  > Rev A Cats had no SSMs, only the SRM (SSM2040) and SRM II (SSM2044).
> I have never seen the SRM service manual, only the original and SRM II.
> Are you sure you have the SRM service manual? That would be great to
> scan it for everyone if you do.
>  >
>  > Doug
>  > synthparts.com
>  > --- In vintagesynthrepair@yahoogroups.com
> <mailto:vintagesynthrepair%40yahoogroups.com>, "Boddington" <f115@> wrote:
>  > >
>  > > Quick update. The PCB says Rev A but I don't see those SSMs
> anywhere. This appears to contradict some old thread on the versions
> that exist. ?
>  > >
>  > >
>  > >
>  > > --- In vintagesynthrepair@yahoogroups.com
> <mailto:vintagesynthrepair%40yahoogroups.com>, "Boddington" <f115@> wrote:
>  > > >
>  > > > I've had the SRM service notes for years but has anyone got
> schenatics for the earlier builds? I have a Rev A in front of me here
> and could use the schems for it. Gotta hand it to Octave though. Each IC
> is already socketed! Nice.
>  > > >
>  > >
>  >
>
> 
>
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Hey you're absolutely right. My bad. I thought there was a Rev A that applied to the pre SRMs. Thank for reminding me. That was from (bad) memory. 

In that case the schems I have are in fact correct. The manual on the site mentioned here is the same SRM one that's everywhere. There's also a rather rough Discrete one kicking around online but it's equially low quality. I haven't seen an SRMII anywhere either but if I come across one I'll be happy to share it.

Redundant thread finished! :)

I'm currently working on 3 Octave Cat SRMs.  I assume to some degree they are similar to the other rev's so I'll share a few things I've taken note of:
-The black 2k Tempco resistors go bad on these things.  Measure them first
-These 2k Resistors are glued to the SSM chips and CA3046chips covering what they actually are.
-There is one of the screws for the left side that needs to be shorter than the others when put back in.  In two of these cats someone put the longer screw into this place and it pushes the yellow axial .47uf cap into other components and breaks them.  Watch for this.
-When repairing the keys, it seems that the bottom jwire needs to leave the bus bar last when key off or it will trigger a lower pitch.

Thats all I can think of right now, hope this helps anyone.

Greg (ZAIUSZ)

--- In vintagesynthrepair@yahoogroups.com, "Boddington" <f115@...> wrote:

>
> I've had the SRM service notes for years but has anyone got schenatics for the earlier builds? I have a Rev A in front of me here and could use the schems for it. Gotta hand it to Octave though. Each IC is already socketed! Nice.
>

Thanks Greg! All good tips.