My completed Oberheim SEM project

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t_tangent
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My completed Oberheim SEM project

Post by t_tangent »

I finally finished my Oberheim SEM project. It took some time due to a few delays and some small issues that needed resolving. But all in all it went quite well, and its now working well and sounds fantastic. Anyway, thought some of you might like to see the end result.
12 A clearer view (Medium).JPG
12 A clearer view (Medium).JPG (218.32 KiB) Viewed 1807 times
11a Unit connected and working (Medium).JPG
11a Unit connected and working (Medium).JPG (207.6 KiB) Viewed 1807 times
11b Unit connected and working (Medium).JPG
11b Unit connected and working (Medium).JPG (220.18 KiB) Viewed 1807 times
11c Unit connected and working (Medium).JPG
11c Unit connected and working (Medium).JPG (201.74 KiB) Viewed 1807 times
10e Back Panel fitted & connected to a Yamaha PA-10 linelump (Medium).JPG
10e Back Panel fitted & connected to a Yamaha PA-10 linelump (Medium).JPG (146.91 KiB) Viewed 1807 times
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t_tangent
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Re: My completed Oberheim SEM project

Post by t_tangent »

The SEM panel when I first bought it, and after getting it silk screened
1a SEM Front panel- As it came from seller (Medium).JPG
1a SEM Front panel- As it came from seller (Medium).JPG (188.06 KiB) Viewed 1806 times
1b SEM PCB - As it came from seller (Medium).JPG
1b SEM PCB - As it came from seller (Medium).JPG (313.76 KiB) Viewed 1806 times
4 SEM panel after Silk Screen (Medium).JPG
4 SEM panel after Silk Screen (Medium).JPG (222.91 KiB) Viewed 1806 times
5 IO Panel before wiring (Medium).JPG
5 IO Panel before wiring (Medium).JPG (143.03 KiB) Viewed 1806 times
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t_tangent
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Re: My completed Oberheim SEM project

Post by t_tangent »

Wiring it up
6a IO Panel after wiring - before swapping the 2 purple wires on bottom right VCF CV2 pot which are incorrectly placed in this photo (Medium).JPG
6a IO Panel after wiring - before swapping the 2 purple wires on bottom right VCF CV2 pot which are incorrectly placed in this photo (Medium).JPG (185.4 KiB) Viewed 1804 times
6b SEM & IO Panel after wiring - before swapping the 2 purple wires on bottom right VCF CV2 pot which are incorrectly placed in this photo (Medium).JPG
6b SEM & IO Panel after wiring - before swapping the 2 purple wires on bottom right VCF CV2 pot which are incorrectly placed in this photo (Medium).JPG (235.16 KiB) Viewed 1804 times
10a SEM panel installed & connected (replaced 220uF axial caps, transistor & regulators) (Medium).JPG
10a SEM panel installed & connected (replaced 220uF axial caps, transistor & regulators) (Medium).JPG (255.72 KiB) Viewed 1804 times
10b IO panel installed & connected (need cable tie holder for top cables) (Medium).JPG
10b IO panel installed & connected (need cable tie holder for top cables) (Medium).JPG (217.4 KiB) Viewed 1804 times
10d SEM & IO Panels fitted with back panel open (Medium).JPG
10d SEM & IO Panels fitted with back panel open (Medium).JPG (222.19 KiB) Viewed 1804 times
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astroman
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Re: My completed Oberheim SEM project

Post by astroman »

nice one - and congrats for the job 8)
dawman
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Re: My completed Oberheim SEM project

Post by dawman »

Incredible sound too I bet.
Is it 2 voice or monophonic?

Thanks T.
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t_tangent
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Re: My completed Oberheim SEM project

Post by t_tangent »

thanks astroman and dawman.

No it has 2 VCO's but it's only monophonic, the black panel is just for Ins & Outs. I read that Tom Oberneim said a 2 voice was his preferred number of SEMs, and it would be nice to add 1 more to this...although I woudn't mind a 4 voice. :) I remember seeing an 8 voice once and they sound incredible, but they are massive.
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garyb
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Re: My completed Oberheim SEM project

Post by garyb »

very nice, i like it.
the phone jacks could be upgraded would be my only criticism. rhat said, i'm impressed. the audio business was once made of products like this. ask Bob.
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Bud Weiser
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Re: My completed Oberheim SEM project

Post by Bud Weiser »

cool, great work !
Especially your patch panel looks amazing !

But ehhhmmmm,- now you need 7 more !

:D

Bud
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valis
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Re: My completed Oberheim SEM project

Post by valis »

I'm all in for 7 more as well. Nice work, it feels great to make things by hand.
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spacef
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Re: My completed Oberheim SEM project

Post by spacef »

looks very clean. congrats !
i would have done the back as a door that can be opened easily (like...a door, lol) rather than screws, but i suppose you don't go in there often to change jumpers or add modules...
That's what I have done on my modular and it is really cool not to have to unscrew everything (but it is not complete as is yours, so i still need easy access).
congrats again
plug-ins for scope
SpaceF website
SC website
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t_tangent
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Re: My completed Oberheim SEM project

Post by t_tangent »

Thanks for the kind words everyone, and I appreciate the advice for improvements as well.

Gary, you are right I should have used better quality phone jacks such as the Switchcraft 112APCX sockets. At the time I was getting parts together I didnt know how it would all turn out and the wiring looked quite daunting at first so I was trying to keep costs down. I recall the price difference between these sockets and the Switchcraft was around £50. I probably will put Switchcraft sockets in at some point especially if these start playing up although they seem to be ok so far....we'll see. :)

Spacef, yes I did think about making the back panel open on a hinge like a door, but I think in the end I was in too much of a hurry to finish it. :) I remember you posted up some photos of your modular a short while ago so I'll have another look at how you did that. I don't really need access to the inside of this unit except for calibration or repairs but if that changes I may try to work out how to add a hinge. :)

Anyways, thanks again all, and yes, now to look out for 7 more, LOL.
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GordonGekko
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Re: My completed Oberheim SEM project

Post by GordonGekko »

really is a beauty, congrats!
and it all worked first time you switched it on? amazing
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t_tangent
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Re: My completed Oberheim SEM project

Post by t_tangent »

Thanks

No, the first time I tuned it on it didn’t work at all, but luckily I found out quite quickly that it was only a transistor that had blown and had taken down the negative rail, probably due to one of the caps failing. But it was an easy fix, just replaced those parts and for good measure the other cap since they were over 40 years old.

second time on it worked fine :)
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GordonGekko
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Re: My completed Oberheim SEM project

Post by GordonGekko »

Damn :D
dawman
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Re: My completed Oberheim SEM project

Post by dawman »

A 4 voice set up with a 1-3 (1 mono/3 poly) configuration would be life altering.

I remember 15 years ago when I first joined the Z I was desperate for the OBX and SEM sounds.
While getting close in modular for a few bread and butter sounds, it could never get that true discrete audio quality of the beasts.

You have to share some sounds when you get time.
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dante
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Re: My completed Oberheim SEM project

Post by dante »

Well done. This has inspired me to get the Arturia SEM V version to complement my Obsession :lol:
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t_tangent
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Re: My completed Oberheim SEM project

Post by t_tangent »

Jimmy, yes a 4 voice would be wonderful. In fact I remember it was largely you who was resoponsible for me getting my first synth, Sharc had posted here that his TB-303 wa for sale and you indirectly convinced me to go for it. Then soon after that I got an Oberheim Matrix 6R and you kindly sent me an Oberheim Sticker. :)

And yes, I am trying to get some sound examples sorted out. :)

Dante, sounds like a plan. I am sure there was a discussion here on the Z before about the Oberheim sound being one of the few emulations that Scope doesnt really have a device for, although I will have to do a comparison now with Orbitone Syn-Chrome which I always liked. But sure, go for it, the Arturia SEM should do the job nicely. Alternatively there is the Brainworx bx_oberhausen, or G-Force OB-E which is based on the 8-Voice although sadly is Mac only at the moment.
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valis
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Re: My completed Oberheim SEM project

Post by valis »

bx_oberhausen, SEM V & DSP56300 Emulation?
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t_tangent
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Re: My completed Oberheim SEM project

Post by t_tangent »

That DSP emulator looks interesting. Will have to give that a look, cheers for the heads up Valis.
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valis
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Re: My completed Oberheim SEM project

Post by valis »

Eventually I presume it will have software frontends. In the meantime you have to address it just like the hardware. Worth noting that Magnus Lidström also previously made a TX16W VST/AU software emulator which in many ways is conceptually similar.
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