From atomic@netcom.com Tue Sep 13 11:38:35 1994 Date: Tue, 13 Sep 1994 08:54:21 -0700 (PDT) From: atomic city To: Analogue Heaven Mailing List Subject: Differences between the OB-Xa and OB-8 Haible J. ZFE BT SE 42 jotteth.... > >The OB-8 has a design that must have been *less* expensive than the >OB-Xa's. As digital technology had increased, they could replace a lot >of cost-intensive trimmers by software calibration. They also added a lot of >fully software-based features in the OB-8. There is a "second page" which >assigns a second parameter to almost any knob and switch on the front >panel. (Two software-generated Delay-Attack-envelopes for modulation >rate/depth for example). Adding all these digital features, they let >the signal path almost untouched. Yes, they changed the OB-Xa's two >filter chips to a single one that is now switched between 2-pole and 4-pole >mode (with analogue switches), but the circuit is equivalent to the original >one. They kept the analogue envelope generators as well, which is very >important for a fat sound. (This is the great difference to the Matrix >models!) > >This all makes the OB-8 a much more powerful and relyable synth than the >OB-Xa. Some people claim that they sound different, but I can't hear any >difference (if you think the OB-8 doesn't sound as fat as the OB-Xa, just >don't press Autotune so often !!) - and the signal path is definetly the >same. Well-written and all true and accurate. Let me add one point of anecdotal/technical evidence to make things a bit more clear in context; the OB-X and its successor the OB-Xa were actually quite different, internally, from the OB-8, in terms of layout of parts (at least that's what I've been told by techs who worked on them), despite similarities in front panels and sound paths..... The OB-X series was the outgrowth of the old Oberheim n-Voice synths, to try to compete with the Prophets by providing a common front panel and a programmer (at the cost of different settings per voice). However, at least part of the innards were still on separate cards per voice! The OB-Xa was sold by retailers in four, six, and eight voice versions, with prices scaled accordingly. With the OB-8, the shift was made to provide a common voice board for all eight voices, with attendant reductions in complexity and price; I don't have the exact figures here in front of me, but the price from the OB-Xa to the OB-8 plummeted by at least $1000 list, probably more like $1500. The OB-8 was considered an incredible bargain, and many old OB-Xa users and folx who had been avoiding polysynths jumped on it. Fond memory: I was in NYC in the winter of 1983 for Laurie Anderson's "United States Live" show at the BAM, and stopped in with my girlfriend at Sam Ash to show her some synths. I was demonstrating the OB-8 to her when I suddenly realized there was someone looking over my shoulder and listening; I turned, expecting an annoyed salesdroid, and found myself face to face with Paul Shaffer. Me: "OH! Uh...buh...um...." PS: "Hi, there." Me: "Um... have I made any mistakes yet?" PS: "Oh, no! You're doing fine." He wandered off, and my girlfriend asked me who he was. (This was 1983, remember.) Brush With Fame. ;) -- mike metlay * atomic city * box 81175 pgh pa 15217-0675 * atomic@netcom.com --------------------------------------------------------------------------- "Oh drat, these computers are so naughty and so complex, I could just PINCH them." (m. t. martian) From MARSHALLR@opsusa.sms.siemens.com Sat Nov 12 13:37:23 1994 Date: Sat, 12 Nov 1994 13:47 EST From: MARSHALLR@opsusa.sms.siemens.com To: PPGWave@aol.com, analogue@magnus.acs.ohio-state.edu Subject: RE: OB8 Info > Somehow, the OBs get lost under the storm of Xpanders, >Jupiters, and Prophets that people are always talking about! So go get one - >sell your JV80 to get one ;-> Compared to what 5 voice P-5s and 6 voice Memorymoogs are going for, the OB's, both the OB-8s and OB-Xa's, are still bargains, ( and are probably due to escalate in price next...). I think it is only because there are so many on the used market that they aren't more expensive. >That's the scoop - did I miss anything? The OB8 was initally sold w/o midi, as Oberheim wanted to promote their own, proprietary bus. OB8s with midi jacks on the wooden end panels were units that had midi retrofitted. Those units with midi jacks on the back panel came from the factory. The later OB8s have the "page 2" functions silkscreened on the front panel, so you don't have to refer to your tattered pull-out....Interestingly, after comparing the basic sound of the OB8 with an OB-Xa side-by-side, with an identical rez patch, I would give the nod to the OB-Xa. With a short attack time, the OB-Xa had a bit more punch to it. It also seemed a little more "crystaline", (this may not be a completely fair observation, since I may have upgraded the TLO-81's in the output buffer to OP-176 on this Xa, can't remember....). Tom Ob. has commented that the Xa sounds "fatter", because of sloppier tuning, but with version "C" or "G" firmware, the tuning routine was improved on the Xa, and I did not notice this effect. The difference in "punch" may be because the 8 generates it's envelopes in software, whereas the Xa uses a curtis chip, (ie hardware). The 8 certainly wins points on programming flexibility, with the "page 2" functions, appegiator, etc., and it's about 15 lbs lighter! BTW- I have midi kits for the Xa, for anyone who has one, and would want to midify it. Call (215) 559-7382 if interested. Rich M.