Just bought an Oberheim OB8....wow!

Discussions about anything analog, digital, MIDI, synth technology, techniques, theories and more.
adhmzaiusz
Active Member
Active Member
Posts: 270
Joined: Tue Jan 29, 2008 8:27 am

Re: Just bought an Oberheim OB8....wow!

Post by adhmzaiusz » Tue Oct 22, 2013 5:02 am

Z wrote: EDIT: Sorry, I confused the OB-X / Xa's innards with the OB-8's. adhmzaiusz was correct, that there are only 2 voice boards, but each voice board has all the components for a single voice arranged in a rectangle in a fashion similar to individual voice boards of the OB-X / Xa.
The OB8 was my first major repair endeavor, I learned a lot from it :thumbright:

IMO the OB8 is an extremely simple synthesizer inside, at least as far as the voice boards go. It's a very nicely laid out circuit board and it really helps that all of the ICs are socketed. There are no rare parts other than the CEM's, all of the 74LS logic chips are very easily obtained.

My only advice when swapping out IC's in this-- don't bother with an IC extractor they are more trouble than they are worth. Best thing I ever learned to remove them from the socket is to use a tiny flat head screw driver and gently pop each of the short ends of the IC little bit by bit until its free. Just a little bit on each side until it comes loose, this will keep the pins from bending too much.

Years ago in my learning experience I made the mistake of trying to pop one of the EPROMs using the extractor and one of the legs broke off, it was a pain in the a*s to carefully create a new pin without damaging something else. But anyway go ahead and make mistakes, learning how to correct them makes us strong!
‹‡›

Floss
Junior Member
Junior Member
Posts: 162
Joined: Fri Oct 26, 2012 12:08 am

Re: Just bought an Oberheim OB8....wow!

Post by Floss » Tue Oct 22, 2013 5:12 am

Thanks I will get to it tomorrow!!!

Did any of you guys calibrate your own Obie?? was it a pain?

Also, I heard about the HPF mod. I feel like the people at oberheim had to have put this restriction on for good reason! anyone undo it?

Midi___ I see some OBIE 8 with Midi on the side, mine is on the back... whats the difference? is mine older?

<--- that is my obie by the way... and it still has that problem in the video :lol:

User avatar
synthroom
Senior Member
Senior Member
Posts: 875
Joined: Sat Sep 08, 2012 3:16 pm
Real name: Kirk
Gear: Fairlight IIx(!), JP-8, D-50, S-50+550, S-760, JX-3P, JD-800, EII, Emax II, Mini, ARP 2600, P-5 Rev.1, Pro-One, Performer, K1m, K5m, few other things.
Location: pdx
Contact:

Re: Just bought an Oberheim OB8....wow!

Post by synthroom » Tue Oct 22, 2013 1:52 pm

My understanding is that the MIDI on the back (mounted in the sheet metal chassis) is a factory installed MIDI interface. The ones on the side, (typically on the left since the panning pots are on the right) are MIDI upgrades.

So if you have it in the back, that indicates you have a late model OB-8. The serial number on mine is C40602 - I think it was made in 1983. Mine also had one of the later ROM revisions. I had someone I found in a synth forum burn me a set of ROMs to bring mine up to the last revision.
Fairlight IIx (Mid-Life Crisis - cheaper than a Corvette!)
Roland JP-8, D-50, S-50, S-550(2x), S-760(2x), JX-3P, JD-800
EII, Emax II, Minimoog, ARP 2600, P-5 Rev.1 (broken...), Pro-One, Crumar Performer, K1m, K5m, MS-2000B, Virus KC, a few other things.

User avatar
synthroom
Senior Member
Senior Member
Posts: 875
Joined: Sat Sep 08, 2012 3:16 pm
Real name: Kirk
Gear: Fairlight IIx(!), JP-8, D-50, S-50+550, S-760, JX-3P, JD-800, EII, Emax II, Mini, ARP 2600, P-5 Rev.1, Pro-One, Performer, K1m, K5m, few other things.
Location: pdx
Contact:

Re: Just bought an Oberheim OB8....wow!

Post by synthroom » Tue Oct 22, 2013 1:55 pm

Seems like the pot needs replaced - from watching the video.
Fairlight IIx (Mid-Life Crisis - cheaper than a Corvette!)
Roland JP-8, D-50, S-50, S-550(2x), S-760(2x), JX-3P, JD-800
EII, Emax II, Minimoog, ARP 2600, P-5 Rev.1 (broken...), Pro-One, Crumar Performer, K1m, K5m, MS-2000B, Virus KC, a few other things.

User avatar
synthroom
Senior Member
Senior Member
Posts: 875
Joined: Sat Sep 08, 2012 3:16 pm
Real name: Kirk
Gear: Fairlight IIx(!), JP-8, D-50, S-50+550, S-760, JX-3P, JD-800, EII, Emax II, Mini, ARP 2600, P-5 Rev.1, Pro-One, Performer, K1m, K5m, few other things.
Location: pdx
Contact:

Re: Just bought an Oberheim OB8....wow!

Post by synthroom » Tue Oct 22, 2013 2:01 pm

Floss - you hinted at the possibility of OB-8s needing recalibration from tape backups. I've heard that too.

It seems the OB-8 saves calibration data on the tape when a backup is made, so if one uses a tape backup made by someone else, then you will need to recalibrate the OB.

Perhaps someone else that has OB-8 experience can confirm that.
Fairlight IIx (Mid-Life Crisis - cheaper than a Corvette!)
Roland JP-8, D-50, S-50, S-550(2x), S-760(2x), JX-3P, JD-800
EII, Emax II, Minimoog, ARP 2600, P-5 Rev.1 (broken...), Pro-One, Crumar Performer, K1m, K5m, MS-2000B, Virus KC, a few other things.

Floss
Junior Member
Junior Member
Posts: 162
Joined: Fri Oct 26, 2012 12:08 am

Re: Just bought an Oberheim OB8....wow!

Post by Floss » Tue Oct 22, 2013 6:10 pm

Yep I've heard this too! Everywhere!

How much lets say the 2 voices in question is gonna cost me??

User avatar
synthroom
Senior Member
Senior Member
Posts: 875
Joined: Sat Sep 08, 2012 3:16 pm
Real name: Kirk
Gear: Fairlight IIx(!), JP-8, D-50, S-50+550, S-760, JX-3P, JD-800, EII, Emax II, Mini, ARP 2600, P-5 Rev.1, Pro-One, Performer, K1m, K5m, few other things.
Location: pdx
Contact:

Re: Just bought an Oberheim OB8....wow!

Post by synthroom » Tue Oct 22, 2013 9:11 pm

I bought a CEM 3340 VCO from synthparts last year for my OB-8. Try here:
http://search.ebay.com/_W0QQfgtpZ1QQfrp ... thQ2dparts

Kirk
Fairlight IIx (Mid-Life Crisis - cheaper than a Corvette!)
Roland JP-8, D-50, S-50, S-550(2x), S-760(2x), JX-3P, JD-800
EII, Emax II, Minimoog, ARP 2600, P-5 Rev.1 (broken...), Pro-One, Crumar Performer, K1m, K5m, MS-2000B, Virus KC, a few other things.

User avatar
synthparts
Senior Member
Senior Member
Posts: 779
Joined: Sun Oct 09, 2011 12:05 pm
Location: SF Bay Area, CA
Contact:

Re: Just bought an Oberheim OB8....wow!

Post by synthparts » Tue Oct 22, 2013 10:05 pm

Thanks for the link. I can offer a slightly better price direct than through ebay. I can also provide a set of the latest ROMs.

The EG offset calibrations are stored to tape. The OB-8 has probably the easiest calibrations of any analog polysynth. It is really well done. You essentially just use the first 8 keys to select the voices and then adjust the trimmers until 2 LEDs light up.
Vintage Synth Parts - http://www.synthparts.com

Floss
Junior Member
Junior Member
Posts: 162
Joined: Fri Oct 26, 2012 12:08 am

Re: Just bought an Oberheim OB8....wow!

Post by Floss » Tue Oct 22, 2013 10:56 pm

Kirk thats it?!

I hear people talking about Oberheim voice cards being like thousands of dollars lol! this is good news.
Synthparts you got a Pot for me?!

Floss
Junior Member
Junior Member
Posts: 162
Joined: Fri Oct 26, 2012 12:08 am

Re: Just bought an Oberheim OB8....wow!

Post by Floss » Wed Oct 23, 2013 1:17 am

This thing in split mode is rediculous!!!!!


I need that HPF Mod Now!!!!! massive


My favorite thing about the synth is the panning. There is no way I can use a Prophet 5 after this.

User avatar
synthroom
Senior Member
Senior Member
Posts: 875
Joined: Sat Sep 08, 2012 3:16 pm
Real name: Kirk
Gear: Fairlight IIx(!), JP-8, D-50, S-50+550, S-760, JX-3P, JD-800, EII, Emax II, Mini, ARP 2600, P-5 Rev.1, Pro-One, Performer, K1m, K5m, few other things.
Location: pdx
Contact:

Re: Just bought an Oberheim OB8....wow!

Post by synthroom » Wed Oct 23, 2013 6:28 am

The panning is cool. And it's so simple for them to do. Too bad other synths didn't have that option.

Synthparts - if that's all there is to the calibration, that's not too bad. I guessed it would have been more complicated for some reason.
Fairlight IIx (Mid-Life Crisis - cheaper than a Corvette!)
Roland JP-8, D-50, S-50, S-550(2x), S-760(2x), JX-3P, JD-800
EII, Emax II, Minimoog, ARP 2600, P-5 Rev.1 (broken...), Pro-One, Crumar Performer, K1m, K5m, MS-2000B, Virus KC, a few other things.

User avatar
Bitexion
Synth Explorer
Synth Explorer
Posts: 4230
Joined: Fri Apr 15, 2005 7:43 pm
Gear: Alesis Andromeda A6
Roland D-50
Creamware Minimax
Yamaha DX7s
Analogue Systems modular
Ensoniq SQ-80
Waldorf Blofeld
Location: Drammen, Norway

Re: Just bought an Oberheim OB8....wow!

Post by Bitexion » Wed Oct 23, 2013 12:07 pm

Floss wrote:This thing in split mode is rediculous!!!!!


I need that HPF Mod Now!!!!! massive


My favorite thing about the synth is the panning. There is no way I can use a Prophet 5 after this.
Nice, send your Prophet to me then I never had one :lol:

User avatar
synthroom
Senior Member
Senior Member
Posts: 875
Joined: Sat Sep 08, 2012 3:16 pm
Real name: Kirk
Gear: Fairlight IIx(!), JP-8, D-50, S-50+550, S-760, JX-3P, JD-800, EII, Emax II, Mini, ARP 2600, P-5 Rev.1, Pro-One, Performer, K1m, K5m, few other things.
Location: pdx
Contact:

Re: Just bought an Oberheim OB8....wow!

Post by synthroom » Wed Oct 23, 2013 2:08 pm

I've got one, and it (Rev 1) has been busted many more years than my OB-8 was.
Fairlight IIx (Mid-Life Crisis - cheaper than a Corvette!)
Roland JP-8, D-50, S-50, S-550(2x), S-760(2x), JX-3P, JD-800
EII, Emax II, Minimoog, ARP 2600, P-5 Rev.1 (broken...), Pro-One, Crumar Performer, K1m, K5m, MS-2000B, Virus KC, a few other things.

commodorejohn
Synth Explorer
Synth Explorer
Posts: 1562
Joined: Mon Aug 12, 2013 2:39 am
Real name: John
Gear: Roland JX-10/SH-09/MT-32/D-50, Yamaha DX7-II/V50/TX7/TG33/FB-01, Korg MS-20 Mini/ARP Odyssey/DW-8000/X5DR, Ensoniq SQ-80, Oberheim SEM
Location: Sacramento, CA
Contact:

Re: Just bought an Oberheim OB8....wow!

Post by commodorejohn » Wed Oct 23, 2013 6:05 pm

Well, Bitexion certainly doesn't want a broken keyboard.

So I'll take it :D
Computers: Amiga 1200, DEC VAXStation 4000/60, DEC MicroPDP-11/73

User avatar
synthroom
Senior Member
Senior Member
Posts: 875
Joined: Sat Sep 08, 2012 3:16 pm
Real name: Kirk
Gear: Fairlight IIx(!), JP-8, D-50, S-50+550, S-760, JX-3P, JD-800, EII, Emax II, Mini, ARP 2600, P-5 Rev.1, Pro-One, Performer, K1m, K5m, few other things.
Location: pdx
Contact:

Re: Just bought an Oberheim OB8....wow!

Post by synthroom » Thu Oct 24, 2013 3:49 am

Well, it's been with a tech for nearly a year, so I'll have to get it back first....
Fairlight IIx (Mid-Life Crisis - cheaper than a Corvette!)
Roland JP-8, D-50, S-50, S-550(2x), S-760(2x), JX-3P, JD-800
EII, Emax II, Minimoog, ARP 2600, P-5 Rev.1 (broken...), Pro-One, Crumar Performer, K1m, K5m, MS-2000B, Virus KC, a few other things.

Post Reply