OBERHEIM SYNTH

Hi all.Can anyone tell me what the switches on the  inside left side that are visible when you open up the top?
               Thanks
                 Jim

It depends on the version of OBX you have.  
1) If you have 5 big switches, the three on the right are used to tell the OBX how many voice cards to use (typically 4,6 or 8, but I have my running on 7).  The two on the left or for "testing", and I think one of them disables auto-tune, but I am not certain. The other switch I have never been able to figure out. (Anyone know???)

2)If you have a bunch of small dip switches - these turn on/off voices individually.  If there are more than 8, I don't know what the extras do.  

That is the most I can help. Hopefully someone else can fill in the details.



--- In oberheim@yahoogroups.com, "jahg88" <jahg88@...> wrote:

>
> Hi all.Can anyone tell me what the switches on the  inside left side that are visible when you open up the top?
>                Thanks
>                  Jim
>

I have the "5" switch version.Which position is considered "on"?
                        Jim

I have to take mine out of the rack, open it up and look in side.  As I recall, "Up" is on, but let me double check. 
--- In oberheim@yahoogroups.com, jim finch <jahg88@...> wrote:

>
> I have the "5" switch version.Which position is considered "on"?
>                         Jim
>

Ok - worked on the Beast some this weekend...
According to the services manual, after calibrating, "Turn off test switch 1 (set to the up position)."  So they claim "up" is "off".  

However, I have my switches set as follows(from left to right) (1)Down, (2)Down, (3)Up, (4)Up, (5)Down.

Again, the last three switches determine the number of voices.  I have my set for voices.  If I want 8 voices I set the last switch to the up position.

In an earlier note, I talked about one VCO on voice 5 having a strange +5V auto-tune voltage that was throwing the oscillator to the wrong pitch.  It turns out that this was caused by switch 2 being in the Up position. When I put switch 2 down, the auto-tune seemed to work correctly.  All my voices/OSC have an auto-tune voltage of between about +2.3 and +2.8V now.  

Anyway, my connectors (wires from motherboard to voice trays, voice cards connections to trays) continue to drive me crazy.  Everything works, but the connectors never seem to work 100% and I lose a voice or an OSC or PW or a gate or something constantly... I have to open things up and work the connectors to get good connections.  I have all sorts of jumpers to from the motherboard to try to cure the most chronic problems, but it is getting out of control. 

Has anyone done a "permanent" upgrade to end this connector issue once and for all?  If yes, can you tell me what you did, where you got the parts, and send me pictures? 

Thanks. 





--- In oberheim@yahoogroups.com, "nelsonj_sce" <nelsonj_sce@...> wrote:

>
> 
> I have to take mine out of the rack, open it up and look in side.  As I recall, "Up" is on, but let me double check. 
> --- In oberheim@yahoogroups.com, jim finch <jahg88@> wrote:
> >
> > I have the "5" switch version.Which position is considered "on"?
> >                         Jim
> >
>

My previous post is related to the OBX.Question was "What do the "test 1"and "test 2" switches do on the panel pcb.Someone? clarified what the other three switches do.There is nothing in the service manual about the switches.

OK - per my own note below, I actually tracked down the replacement parts for my voice board connectors.  Last night I replace all my connectors on a single voice board and the results are fantastic.  Parts are an exact fit.  I have ordered more parts and will be replacing all connectors on all 8 of my voice boards.  With shipping, parts for all 8 board will cost about $60. 

I ordered from Mouser.  They are Molex bottom entry, solder-in parts.  

The following are the part numbers, and the number of parts needed for EACH voice board. 

538-09-52-3082  Rectangular Connectors PCB RECPT 8P BOTTOM ENTRY
1 per board

538-09-52-3042  Rectangular Connectors PCB RECPT 4P BOTTOM ENTRY 
1 per board

538-09-52-3032  Rectangular Connectors PCB RECEPT 3P Bottom entry
3 per board

538-09-52-3102  Rectangular Connectors PCB RECPT 10P BOTTOM ENTRY  
2 per board



--- In oberheim@yahoogroups.com, "nelsonj_sce" <nelsonj_sce@...> wrote:

>
> Ok - worked on the Beast some this weekend...
> According to the services manual, after calibrating, "Turn off test switch 1 (set to the up position)."  So they claim "up" is "off".  
> 
> However, I have my switches set as follows(from left to right) (1)Down, (2)Down, (3)Up, (4)Up, (5)Down.
> 
> Again, the last three switches determine the number of voices.  I have my set for voices.  If I want 8 voices I set the last switch to the up position.
> 
> In an earlier note, I talked about one VCO on voice 5 having a strange +5V auto-tune voltage that was throwing the oscillator to the wrong pitch.  It turns out that this was caused by switch 2 being in the Up position. When I put switch 2 down, the auto-tune seemed to work correctly.  All my voices/OSC have an auto-tune voltage of between about +2.3 and +2.8V now.  
> 
> Anyway, my connectors (wires from motherboard to voice trays, voice cards connections to trays) continue to drive me crazy.  Everything works, but the connectors never seem to work 100% and I lose a voice or an OSC or PW or a gate or something constantly... I have to open things up and work the connectors to get good connections.  I have all sorts of jumpers to from the motherboard to try to cure the most chronic problems, but it is getting out of control. 
> 
> Has anyone done a "permanent" upgrade to end this connector issue once and for all?  If yes, can you tell me what you did, where you got the parts, and send me pictures? 
> 
> Thanks. 
> 
> 
> 
> 
> 
> --- In oberheim@yahoogroups.com, "nelsonj_sce" <nelsonj_sce@> wrote:
> >
> > 
> > I have to take mine out of the rack, open it up and look in side.  As I recall, "Up" is on, but let me double check. 
> > --- In oberheim@yahoogroups.com, jim finch <jahg88@> wrote:
> > >
> > > I have the "5" switch version.Which position is considered "on"?
> > >                         Jim
> > >
> >
>