Xpantastic!

Hi,

I'm just about to ship the OB-VFD display upgrade beta units out to the 
testers, but I need to identify the right place for the bias 
modification diode on the Matrix-12 power supply board (Xpander is no 
problem, but the M-12 supply is slightly different).

To that end, does anyone please have a copy of the M-12 PSU schematic 
that they could let me have? If not, a good hi-res photo of the PSU 
board may have to suffice...

Many thanks - best regards,

Steve

Steve Lenham
Benden Sound Technology
www.bendentech.co.uk/sound

I have an ORIGINAL XPander service manual- I dont know if the M12 had its own service manual or if the M12 specific things are covered in the Xpander manual. I

Hello Steve,

I have a M12 service manual. And yes, the schematic is slightly 
different from the xpander. I have taken a high res photo of it and 
will send it over to you. The service manual does not have a parts 
placement sheet. So as soon as I get my M12 open. I will send one of 
the PSU. 

Best Regards
Karl



--- In xpantastic@yahoogroups.com, "stevelenham" <yahoo@...> wrote:
>
> Hi,
> 
> I'm just about to ship the OB-VFD display upgrade beta units out to 
the 
> testers, but I need to identify the right place for the bias 
> modification diode on the Matrix-12 power supply board (Xpander is 
no 
> problem, but the M-12 supply is slightly different).
> 
> To that end, does anyone please have a copy of the M-12 PSU 
schematic 

> that they could let me have? If not, a good hi-res photo of the PSU 
> board may have to suffice...
> 
> Many thanks - best regards,
> 
> Steve




> 
> Steve Lenham
> Benden Sound Technology
> www.bendentech.co.uk/sound
>

--- In xpantastic@yahoogroups.com, "Karl" <shire03@...> wrote:
>
> Hello Steve,
> 
> I have a M12 service manual. And yes, the schematic is slightly 
> different from the xpander. I have taken a high res photo of it and 
> will send it over to you. The service manual does not have a parts 
> placement sheet. So as soon as I get my M12 open. I will send one 
of 
> the PSU. 
> 
> Best Regards
> Karl

Many thanks, Karl (and Tony too) - that's exactly what I needed. I 
know where the extra diode needs to go now!

If anyone else was wondering, it turns out that the M-12 PSU is 
pretty much a beefed-up version of the Xpander design with separate 
+12V and -12V regulators for each voice board. The -5V rail also gets 
its own winding on the transformer rather than being derived from the 
unregulated -12V.

Best regards,

Steve

Steve Lenham
Benden Sound Technology
www.bendentech.co.uk/sound