# Hit That Perfect Beat, Boy...

- Site: Analog Industries
- Author: Chris Randall
- Date: 2013-06-21
- URL: https://analogindustries.com/2013/06/hit-that-perfect-beat-boy/

[![Analog Beatz. #RT60](https://analogindustries.com/images/ext/farm4.staticflickr.com/3679/9093965677_83d805ccdf.jpg)](https://www.flickr.com/photos/chrisrandall/9093965677/)

As anyone that follows me on Twitter knows, I'm currently in Hood River, Oregon at my family reunion. I spent a chunk of time earlier in the week at J-Hi's studio recording the rhythm parts for what will be the next RT60 release (which, as it happens, will be a double A-side 7" only, no digital. Sue me.)

While there, I became a convert vis-a-vis the SEM module. While I appreciate the power of Oberheim synths, their general sound has never done anything for me. I had not, however, ever used a real SEM. The original one in the picture above (run via CV/Gate outs from the A4) changed my mind in a hurry. I don't know how close the new ones sound to this vintage one, but jesus fuck, what a cool sounding synth. I think I'd need to do a side-by-each comparison, but I may break my moratorium on GAS if the new ones are even in the ballpark.

Speaking of GAS-moratorium-breaking, I recently got a Craigslist score in the form of a like-new DK Synergy II+ with all the Wendy Carlos cartridges, which will get a video and "review" as soon as I get back. Suffice it to say, mind: blown by this thing. I've been trying to coax an emulated Kaypro II in to being able to program it, and I feel I'm not far from success in that regard, but honestly, there are only so many hours I can dedicate to that task that would be better spent doing, you know, my job and stuff.

Anyhow, that's it for now from the Great White North(west). Back to our favorite family sport, trying to belittle each other to the point of tears.

## Comments (42)

**synthetic** (2013-06-21):

The new SEM and the SE Boomstar have been tied on my "synths I don't really need but kinda want" list.

**Duke Fame** (2013-06-21):

Here is recent muffwiggler thread on SEM love:

http://www.muffwiggler.com/forum/viewtopic.php?t=81097

I know I read SOMEWHERE just recently some folks claiming the reissues don't sound as good as the originals. Maybe I can find it in my browsing history. Nevertheless, the majority of the people I've read with the reissues seem to be quite happy with them.

Anyway, damn you for another seal of approval on this $900 sonic widget. Unlike synthetic, don't need but LUST. It's like passing that dream guitar in the front window of the local pawn shop everyday...

**Mike Nickel** (2013-06-22):

I'm sure you have your reasons for making the next RT60 release vinyl only but, that's disappointing. In all honesty, I'll probably still buy it for the "one day" pile but I don't even own a turn table and only listen to music from my computer or phone.

**retrosynth** (2013-06-22):

The 35 year old SEM is better than the new one. It's surface mount instead of through whole components and the older stuff is better than the new stuff. I have two two-voice, three-voice patched out, four-voice, two standalone units, and one I still need to fix.

-Cary

**seancostello** (2013-06-22):

Threads like this bring back memories of "the synths I missed." In this case, it was a synth I ignored: an OB-X for $425, at Starving Musician in Sunnyvale, CA in the late 1990s. I didn't know much about Oberheims at the time. It turns out that the OB-X is essentially 4, 6 or 8 SEMs, with everything voltage controlled. Same VCO/VCF/VCA designs as in SEM. Very different from later Oberheims, where Curtis chips took over most of the heavy lifting.

As far as the new SEMs sounding like the old ones, it probably comes down to whether or not surface mount technology sounds like the older ICs. I would presume that the answer is "sure, why not," but I have zero points of comparison for this. There will probably be a few parts substitutions for the OTAs, with the CA3080 replaced with the LM13700 or something similar.

**MikeF** (2013-06-22):

When I want that feeling - that perfect beat boy feeling, I use an Arturia Oberheim SEM V. Well I think it sounds good.

{slinks away in shame}

**Alan Tomlinson** (2013-06-23):

I find whenever Oregonians are getting out of hand in their fits of self-love, that a brief mention of the Klan's long history in Oregon tends to get people to shut the fuck up; albeit, alas, briefly.

I've heard OB-Xs and OB-8s and I don't recall hearing them sounding like a SEM.

Cheers,

Alan Tomlinson

**retrosynth** (2013-06-23):

Actually, a OBX have two CEM3310s per voice instead of the SEM version which is discrete. (I have an OBX, two OBXa's, and an OB-8.)

-Cary

**Chris Randall** (2013-06-23):

Yeah, none of the OBs sound remotely like a SEM. Totally different topology. I always just assumed a SEM was like a single voice of an OB-X or whatever, but that's not the case at all.

Regarding surface mount versus through-hole, that's not a deciding factor, because physics. Also: math. But the component quality (less) and consistency (much less) are factors. Have to try it for myself.

-CR

**seancostello** (2013-06-23):

I looked to see if Control Voltage in PDX has an SEM in stock. Looks like the answer is no.

**krylenko** (2013-06-23):

I've never seen anyone here link to xkcd, but I just couldn't resist after CR's comment:

https://xkcd.com/435/

**TomE** (2013-06-23):

@MikeF It does sound good, and distinctive. Could be different to a real one from a specific month in 1963 or whatever, but fuck it, it sounds good.

**ToneHead** (2013-06-24):

Joe Zawinul established the cred of these for me back in the late 70s (old guy reference) ... I think he had a Four Voice ... Never did buy any Oberheims myself because the SEMs were a few years before my time, and once you missed the boat on the SEM, the reputation of the later Oberheims was generally "not quite an SEM sound-quality wise".

It's like tube amps - surface mount vs. through-hole may not be a decisive issue, but with circuits this simple, the actual layout of components on the circuit board and particular batches of components can make considerable differences in sound (not a problem in DSP land.) Four Voices were notorious for each of the four SEM units sounding a little different from the others.

**soundsubs** (2013-06-24):

I too love the SEM. I have had old ones (with problems) and the new one.

As for VSTi, well I tried the arturia, and it sucked (of course) but surprisingly, this doesn't suck: http://music.service-1.de/html/sam_synth_plugin.html

no, I don't work for them.

**Adam Schabtach** (2013-06-24):

Argh. Like someone else said, I'd managed to talk myself out of wanting an SEM, and you had to go pick at that scab.

I will accept that through-hole components can produce a circuit that sounds _different_ than one produced with SMT. I will not accept that through-hole components sound inherently better. Ever take the cover off an Apogee converter, or a high-end Eventide? They use SMT. Good enough for them, good enough for me.

Comparing an old SEM and a new one is a tricky proposition because of their relative ages, for starters. There are almost certainly capacitors in that box that behave differently now than they did when the box was built. Also, the old ones were probably built with components that had a wider tolerance than those used in contemporary units. That would explain the differences observed in Four Voices mentioned by ToneHead. So in short I'd expect to hear as much variation between any two old SEMs as between an old one and a new one.

Me, I'd buy a new one simply because it's easier to find, more likely to work for longer, and probably less expensive.

--Adam

**Duke Fame** (2013-06-24):

@CR: My fav threads on here are the geek shop talk, so thank you for posting this. This through-hole-vs-SMT is damned interesting to me as I am a DIY synth guy and like things I can modify with my Weller if need be, and so trying to find an original seems to be the way to go. But at the end of the day, the SMT reissue can come with a ready-to-go plug-n-play CV patch panel, so how can you top that?

Thank you all for the great insight.

**obscurerobot** (2013-06-24):

I'm totally not an EE, but I did do enough EE and (more importantly) physics coursework to be aware that PCB traces can definitely act as capacitors, inductors, and antennas when designed (im)properly.

So the issue is more likely that the PCB designs are different, component tolerances are different, and the fresh new components are different from the aged originals. One of William Gibson's manic otakus could probably perfectly replicate the sound of this, or any other, vintage device. But it would be impossible to recover the cost of that kind of deep research commercially. So we get the best reasonable approximation that can be engineered.

If Paul Allen was a synth-nerd instead of a rocker, then there would probably be a half dozen shops in Seattle building him perfect bespoke replicas of classic synths at $300k a pop.

**seancostello** (2013-06-24):

I just realized why I had that Die Antwoord song stuck in my head for the last few days. Thanks for that, Chris.

**TomE** (2013-06-25):

@soundsubs just recommended the superior sound of a Synthedit VSTi, the world is upside down, people walk on their hands, trees are growing into seeds.

(Actually, ta, I will have a look. I've just NEVER seen anyone dare to do that before. On KVR they even have a filter to hide Synthedit plug ins).

**Chris Randall** (2013-06-25):

Yeah, I'm not going to bother to check the veracity of that claim. If it isn't cross-platform, 32/64, it could sound like the heavens cracking open, angels singing hosannas on high, and the voice of god telling me I've won Powerball and I won't even get as far as downloading it.

-CR

**silent5** (2013-06-25):

What is the round metal thing on the front of this SEM?

**DGillespie** (2013-06-25):

What Adam said.

Also, a big difference is that many of the active components (transistors and op- amps) may not be available anymore. Or if they are, they'll be made by a different process and have slightly different specs.

Layout can make a difference, but at these frequencies I'd be very surprised if that was the difference you'd be hearing. It's probably slightly different parts and and component tolerances, if anything.

**Chris Randall** (2013-06-25):

@silent5: It is a mic stand mount. No idea why it is there.

-CR

**Adam Schabtach** (2013-06-25):

What @DGillespie said.

I just googled up the schematics for the original SEM. There is a pair of CA3080 OTAs in the filter, and one in the VCA. Those chips are no longer made. There are a few left here and there, but I doubt Mr. Oberheim would design a new product based on the tenuous availability of NOS parts. They've probably been replaced with LM137000s. I'm sure that there are threads out there in which the pros and cons of each are hotly debated; bottom line is that the new SEM doesn't have exactly the same parts as the old one, and hence can be expected to not sound exactly the same, even neglecting the variation between old units as described previously.

And yes, stray capacitances etc. from layout generally come into play only in the megahertz range of frequencies. You can't hear their effects. Honest.

In the end, though, who cares? We all know that rational analyses have little to do with synthesizer purchases.

--Adam

**silent5** (2013-06-25):

@CR: I see. I can only assume someone put it there as opposed to the bottom so they could still place it flat on a desktop? Looks a bit like an R2D2 interface.

**Chris Randall** (2013-06-25):

I don't speak Drum, but in looking at it I think it's actually a header (?) for one of those doo-hickies you stick a tom to on a drum rack. This particular SEM has a noise source added internally (that's what that switch turns on and off) and I believe it was used as a synth-drum for the most part. That would explain the placement.

-CR

**Scodiddly** (2013-06-25):

If that's not an Atlas AD-11 mic stand flange adapter then I'll be dipped in the anti-flea medicine of your choice. But then somehow 5/8"-27tpi is the American standard for microphone stands, and gets into all sorts of odd places.

**Chris Randall** (2013-06-25):

Fuck if I know. It's gone now. First thing my tech took off in his quest to return this thing to its former glory.

-CR

**seancostello** (2013-06-25):

@Adam: Apparently the OTA in the LM13600/13700 is identical to the 3080:

http://www.idea2ic.com/LM13600/LM13700.html

**Adam Schabtach** (2013-06-25):

@sean Hah! Interesting. I stand corrected. Good to know--thanks.

--Adam

**mitchell** (2013-06-25):

Late to the dork-off party as usual, but...

I have a new SEM... actually I have the oldest new one. I wrote the owner's manual and Tom paid me by letting me keep his handbuilt prototype (try not to be too jealous of all he hot ass I must get as a result). Tom also "edited" the manual and added lots of of cool punctuation and grammatical errors, silly guy.

I've never played an original so I can't give you my two cents comparo opinion, but I discussed many things about the SEM at length with Tom, and he made every effort to keep the circuit identical. According to Tom, the ONLY audio path component changed in the entire box was the OTA, out of necessity. The other big change was the tuning pot configuration- he said he always hated the old geared pot. (He also hated the beige box and was gonna make the new one black, but everyone he asked, said to leave it, myself included.)

I grilled him at the time about SMT vs. thru-hole, and he pretty much laughed at me- in the "it makes no difference, you're being stupid" kind of way. Y'all can do whatever you like with that tidbit, but that was Tom's opinion. I'm with Adam- I believe any differences you'd hear from old to new have more to do with wonky 70's component tolerances (5%-10% resistors were the norm, as opposed to today's 1% resistors) and ailing 40-year-old caps. And I suspect the differences would be more of a "gee, it's a little different" variety than a "this old one sounds warmer/phatter/insert nebulous adjective of betterness here" thing.

Finally, I don't really have the hands-on in this particular case so maybe I'm talking out my ass, but I wouldn't get too excited about the sound differences between a synth with a discrete envelope generator circuit as opposed to an IC (unless it was an early, slow digitally controlled envelope, which CEM's are not). Though the slopes could be subtly different, an envelope generator isn't in the audio path, it simply controls the action of the VCA (which IS in the audio path).

If anyone's interested, I interviewed Tom when the new SEM was released, 'tis here:

http://www.youtube.com/watch?v=C1FsCGyx1YY

**Chris Randall** (2013-06-25):

Let's back up to the "he hot ass" bit. I'm curious about that.

That aside, any of these old-school guys will say "oh, aren't you adorable" when you bring up SMT v. through-hole "sound" to them. Since the people that think that SMT somehow sounds "worse" than through-hole are overwhelmingly not Tom Oberheim, Dave Smith, Roger Linn, or Bob Moog, I'm gonna have to go ahead and say that they don't know what the fuck they're talking about.

The one difference I'll admit to is that every SMT synth I've played has generally worked, while every through-hole synth I've played has had problems ranging from "huh, that's weird" to "I bet this would be pretty cool if it worked" to "doorstop." So there's that.

(The single exception being this DK Synergy II+, which actually is 100%. The most complicated instrument I've ever purchased works perfectly. Go figure.)

-CR

**Adam Schabtach** (2013-06-26):

@mitchell: Fun interview, thanks. I think I somehow missed part 2 back when those were first posted; it seems unfamiliar.

Nuts. Now I want one of the things, again.

I hope Mr. Oberheim has had good sales with the new SEM. He deserves it.

--Adam

**ToneHead** (2013-06-26):

I agree with what Adam said a few posts ago about stray capacitances mostly applying in the MHz range, but I've done enough DIY analog stuff in the 80s to know circuit layout is critical, but mostly because you can do it wrong and have power supply noise leakage, EM pickup, etc. But I did have excellent high frequency hearing and could often hear differences just from moving components slightly, but that mostly occurs in the presence of a high gain feedback loops typical of fuzzbox circuits, feedback based oscillators, and the like.

**ToneHead** (2013-06-26):

The whole subject of how reductionistic (or not) one can be when dealing with physical circuits reminds me of a story of my dad trying to diagnose a problem in a Univac mainframe back in the day. He'd concluded the problem was in a certain subassembly, but after a day of failing to find the problem where it seemed to be, he traced the problem "upstream" and discovered that someone had used a wiring harness as a cigarette holder, where the cigarette had fused two wires together. The butt was still hanging there.

So my dad had made the reductionistic mistake of assuming nobody would be enough of a jackass to use a wiring harness in a computer destined for NASA as an ash tray. But it was the 60s, and people did stuff like that. It's a wonder those SOBs made it to the moon.

**beauty pill** (2013-06-27):

I am an absolute pleb when it comes to synthesizers, especially compared to you guys, but I really like the Arturia model of this thing for bass.

I would like a real SEM, especially if it sounds twice as rich as the software, as poeple tell me.

But I'm also saving up for a new guitar and amp and you can't have everything in this world.

- c

**shotgunlab** (2013-06-27):

Without a doubt the band pass sweep on an Original SEM is one of the greatest of all time synth sounds!!!

**beauty pill** (2013-06-27):

I think of this instrument as almost purely a bass thing.

But I've never played a real one and don't know that much about synths in general.

- c

**DGillespie** (2013-06-27):

...you can't have everything in this world.

I don't think I've ever seen this sentiment expressed in the context of a synth discussion.

**bongo_x** (2013-06-28):

>Let's back up to the "he hot ass" bit. I'm curious about that. <

I'm pretty sure he meant "Hee Haw ass". Auto correct, you know.

**mitchell** (2013-06-30):

Hey Chris, isn't this new blog supposed to let me correct spelling mistakes? So you guys won't lampoon me when I miss a T?

**Chris Randall** (2013-06-30):

It only lets you correct spelling mistakes that aren't funny.

-CR