OBERHEIM SYNTH group photo

Yahoo Groups archive

OBERHEIM SYNTH

Index last updated: 2026-04-28 23:39 UTC

Message

Re: [oberheim] Re: OB-SX voice board

2007-03-28 by ogusa@lava.net

Unfortunately the second generation OBs were victims of cost cutting -  
when those analog synth makers tried to make the CPU do all the  
control voltage work instead of having chips do it. The  
microprocessors of the era weren't fast enough to create the "snappy"  
voltage changes, so the synths sounded mushy despite having the great  
VCO chips.

That voice board module with analog envelopes driving it etc will  
sound awesome. Good luck with your project.

Peter

  Quoting analogback <gehayman@...>:

> thanks for the info Peter, i have some of ken Stones boards for lfos
> and voltage generators. building it completely modular with a jack
> panel that could interface with other modular gear would be the go. i
> agree, its quite a job but i will have a shot anyway!  i have done a
> lot of synth modifications so i'm confident with that, was just hoping
> someone who may have done this particular project before would chime
> in with any dos or donts!
> greetz
>
> --- In oberheim@yahoogroups.com, ogusa@... wrote:
>>
>> Each of the connections like PWM, ENV etc. are voltage control inputs.
>> THe voice board does not produce envelope or control voltages, they
>> were created by the CPU.
>>
>> You face quite a challenge YOu would have to build at leat 2 envelope
>> generators  and LFOs, as well as several static voltage generators
>> (pots), get voltage control to the envelopes and LFOs and set up a
>> routing matrix. Even on the classic monosynth, the architecture is
>> "normalized" but there are switches for various CV routing otions.
>>
>> Plus much of the Oberheim "sound: came from the many control
>> possibilities (Env mod PW 1 with delay etc). If you want that sound,
>> you are going to have to build half of a a full modular system to
>> support the module.
>>
>> Anyway, unless you're a analog synth designer or advanced hobbyist
>> (like myself), you'll never get it to do what you want.
>>
>> Sorry,
>>
>> Peter
>>
>> Quoting analogback <gehayman@...>:
>>
>> > thanks for the reply Jeffrey,
>> > i found schematics and voice board connector info today, apparently,
>> > the board was from a blue obsx which is supposed to have the same
>> > voice card as an ob xa. but a few questions remain!
>> >
>> > i have a midi-cv converter and +15v -15v & -5v power supply (required
>> > voltages)
>> >
>> > there are a few connector ins/outs that are labeled but not
>> > immediately obvious to me so i will try to get more info!
>> >
>> > if anyone with knowledge of these machines would care to take a look
>> > at this picture, perhaps it could help me determine the less obvious
>> > connection points?
>> >
>> > http://i133.photobucket.com/albums/q55/neonleg/obxapinout.jpg
>> >
>> > thanks!
>> >
>> >
>> >
>> >
>> > --- In oberheim@yahoogroups.com, Jeffrey Nelson <nelsonj_sce@> wrote:
>> >>
>> >> You will need to power it up, and then supply it with
>> >> a gate and CV.  A good place to start is a Midi to CV
>> >> converter.  You can get them off of Ebay around $75.
>> >>
>> >> The problem will be the power supply, you will likely
>> >> need +/- 12V and +/-5V and others perhaps.
>> >>
>> >> The other problem is that you need to provide voltages
>> >> for all of the envelopes, VCF filter and res...
>> >>
>> >> Finally, you need to build an final output stage for
>> >> overall volume control.
>> >>
>> >> In short, it can be done, but it won't be easy.  Not a
>> >> simple project.  Get a schematic first.  Good luck.
>> >>
>> >>
>> >> --- analogback <gehayman@> wrote:
>> >>
>> >> > hello! i have an obsx voice board that i would like
>> >> > to try and modify
>> >> > in order to use it as a standalone monosynth.. does
>> >> > anyone know if
>> >> > this has been done before? if its possible?
>> >> > obviously the boards
>> >> > connector info would be a great help as well!
>> >> > any info appreciated as i've scoured the net to no
>> >> > avail :(
>> >> > greetz
>> >> >
>> >> >
>> >>
>> >
>> >
>> >
>> >
>> >
>> > Yahoo! Groups Links
>> >
>> >
>> >
>> >
>>
>
>
>
>
>
> Yahoo! Groups Links
>
>
>
>

Attachments

Move to quarantaine

This moves the raw source file on disk only. The archive index is not changed automatically, so you still need to run a manual refresh afterward.