Is anyone working towards an EML 100/200 clone?

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: Kent, Joe., luketeaford, lisa

Post Reply
User avatar
sanders
Veteran Wiggler
Posts: 738
Joined: Tue Feb 03, 2009 4:42 pm

Is anyone working towards an EML 100/200 clone?

Post by sanders » Tue Oct 29, 2019 7:10 pm

Everytime I take a look through the DIY topics I'm always excited to see all the new projects opening, particularly all of the vintage designs being made newly available.

I'm kind of surprised I haven't seen an EML 100 or 200 project yet. It's true these are pretty odd ball instruments, but in terms of DIY assemblies, I'd think they'd make a pretty good candidate. They don't use custom hardware, everythjing looks off the shelf, their design and construction is about as simple as can be. They were known for using mostly opamps instead of a lot of selected matched transistors.

Maybe they're just not well liked and undeserving of attention. In 30 years of interest in analog synthesizers I've only come across about 3 EML synths, and only ever played on an EML once; an EML 500 on display at a Brooklyn music store about ten years ago.

I've read that Laurie Speigel's "the expanding universe" was performed entirely on EML synths, and it's one of my favorite "synth" albums. I presume she liked hers. But then there weren't too many options at that time.

Still, it's strange that there's such a dearth of technical info/photos/activity out there on the EML instruments.

djs
Super Deluxe Wiggler
Posts: 1188
Joined: Wed Sep 01, 2010 8:36 am
Location: South Beloit, IL

Post by djs » Wed Oct 30, 2019 8:40 am

Now you sent me down a rabbit hole looking at EML schematics.

EML200 looks fairly easy to do, although the schematics I'm seeing have a lot of unidentified transistors, other than generic part identifier numbers.
"Noise is what the Earth is made of" - David Bowie

User avatar
Kevin Mitchell
Wiggling with Experience
Posts: 297
Joined: Tue Jun 27, 2017 10:55 am
Location: Springfield, Massachusetts

Post by Kevin Mitchell » Wed Oct 30, 2019 9:26 am

Those aren't generic identifiers. Transistors with "20" are MPSA20(NPN), "70" is MPSA70(PNP). Just cross reference similar parts or observe the EML101 schematic in comparison. At first glance I'm certain there is a modern equivalent to most - if not all of the parts. The two mentioned above may still be in production.

I see it was from an educational synth project based out in Connecticut. That's close to home. I wonder if I can find an original unit nearby :roll:

-KM

SoundPool
Veteran Wiggler
Posts: 584
Joined: Sun Nov 16, 2008 11:15 am
Location: Vienna

Post by SoundPool » Wed Oct 30, 2019 2:17 pm

I'd double check on the Expanding Universe thing, unless the EML was the analog part of the GROOVE system and the computers were doing all the sequencing/controlling. Don't expect to be able to do Patchwork using an EML200 ;)

EMW did a clone of the 200, but I have heard its really shoddy, especially considering the price. I thought about sitting down and trying to do it bit by bit a while ago but didn't have the time. If someone did do a PCB for one I would be very happy to be able to put one together though!

User avatar
sanders
Veteran Wiggler
Posts: 738
Joined: Tue Feb 03, 2009 4:42 pm

Post by sanders » Sat Nov 02, 2019 4:37 pm

SoundPool wrote:I'd double check on the Expanding Universe thing, unless the EML was the analog part of the GROOVE system and the computers were doing all the sequencing/controlling!
This is exactly what they did; the Bell Labs Groove System was designed to digitally sequence voltage controlled instruments; I’ve read that Spiegel used her own EML synths for voicing. This would have included her EML 100 and 200, etc.

User avatar
sanders
Veteran Wiggler
Posts: 738
Joined: Tue Feb 03, 2009 4:42 pm

Post by sanders » Sat Nov 02, 2019 4:50 pm

djs wrote:Now you sent me down a rabbit hole looking at EML schematics.

EML200 looks fairly easy to do, although the schematics I'm seeing have a lot of unidentified transistors, other than generic part identifier numbers.
I can’t seem to find interior photos right now; I wanted to post them; but what I find encouraging about these instruments is how simple the layouts are. If I remember right, the 200 is just 3 small PCBs sandwiched to the front panel and wired to pots, switches, and jacks. There’s hardly anything in these giant wooden boxes.

What would obviously be considered a waste of space today, allowed EML to mount a large open panel design with chunky knobs, solid hardware and plenty of space to maneuver around the controls. Not great for a commercial product today, but it would make an excellent DIY project.

SoundPool
Veteran Wiggler
Posts: 584
Joined: Sun Nov 16, 2008 11:15 am
Location: Vienna

Post by SoundPool » Sun Nov 03, 2019 5:28 am

sanders wrote:
SoundPool wrote:I'd double check on the Expanding Universe thing, unless the EML was the analog part of the GROOVE system and the computers were doing all the sequencing/controlling!
This is exactly what they did; the Bell Labs Groove System was designed to digitally sequence voltage controlled instruments; I’ve read that Spiegel used her own EML synths for voicing. This would have included her EML 100 and 200, etc.
aah ok that makes sense. my copy was sitting in storage so I couldn't have a look at the notes.

While the cabinet is mostly empty and I suppose it could be downsized a little bit in general I also like the idea of a clone that would still have a lot of space on the front panel like the original. With all the switches to me it begs to really be "played" in a way that would be impossible if it were made into a couple of euro sized modules. I also really love its simplicity and how you have to work differently with limited features. one hitch for me with a clone though is I think it becomes a much more interesting instrument if you also have the 300 with it, which gets more involved.

looking at the schems again, while there are transistors which are unclear what they are, they seem to be only 3 or so different kinds and they all have the same reference numbers like 20, or 14. so if someone could see inside of one original and make some notes or figure out what those numbers reference that would be the trickiest part probably.

User avatar
sanders
Veteran Wiggler
Posts: 738
Joined: Tue Feb 03, 2009 4:42 pm

Post by sanders » Sun Nov 03, 2019 6:34 pm

SoundPool wrote: While the cabinet is mostly empty and I suppose it could be downsized a little bit in general I also like the idea of a clone that would still have a lot of space on the front panel like the original. With all the switches to me it begs to really be "played" in a way that would be impossible if it were made into a couple of euro sized modules.
This is exactly what I was thinking; To me, it begs to be reproduced in full scale. Funny thing is, the 200 front panel is actually split in two equal size, top and bottom sections. I don't know for sure, but it looks close to the size of two Serge 4U shop panels, or maybe 2 84hp 3U Euro panels.
SoundPool wrote: looking at the schems again, while there are transistors which are unclear what they are, they seem to be only 3 or so different kinds and they all have the same reference numbers like 20, or 14. so if someone could see inside of one original and make some notes or figure out what those numbers reference that would be the trickiest part probably.
For some reason, I most like the idea of an EML 200 project; Probably because it's self contained, no keyboard, simple box enclosure, etc. That said, I found this video of a lengthy EML 101 breakdown. From what I remember, the 200 is very similar looking inside:

[video][/video]

User avatar
rampy
Common Wiggler
Posts: 206
Joined: Mon May 20, 2013 8:44 am
Location: d/fw

Post by rampy » Sun Nov 03, 2019 11:28 pm

I would love to see a full size EML 200 clone. I've never done research into the design. Does it use multiple uA726 like the 101?

User avatar
fluxmonkey
Super Deluxe Wiggler
Posts: 1850
Joined: Sat Oct 18, 2008 10:05 pm
Contact:

Post by fluxmonkey » Wed Nov 06, 2019 12:45 pm

another hurdle would be the center-tapped pots in critical positions of the VCO and VCF, if I remember correctly
www.fluxmonkey.com

BUILDER FOR HIRE - kits or custom, email me with your needs

User avatar
J3RK
Super Deluxe Wiggler
Posts: 6677
Joined: Tue Dec 22, 2009 12:46 pm
Location: Seattle

Post by J3RK » Wed Nov 06, 2019 1:08 pm

The first thing I would do is maybe contact George Mattson (of Mattson Mini Modular and other notoriety). He has built and restored a ton of EML gear. See video below. He might have some ideas on this, where to get things like the pots, and any component substitutions etc. Worth a try anyway. Very nice guy too.


[video][/video]
Are you lemon? Does your head come to a nub?

User avatar
rico loverde
Super Deluxe Wiggler
Posts: 4043
Joined: Fri Aug 06, 2010 10:40 am
Location: Portland, Oregon

Post by rico loverde » Wed Nov 06, 2019 1:20 pm

works for Darkplace Manufacturing

User avatar
meatcliff
Ultra Wiggler
Posts: 982
Joined: Sat Apr 03, 2010 5:21 pm
Location: Boston New England

Post by meatcliff » Wed Nov 06, 2019 2:30 pm

fluxmonkey wrote:another hurdle would be the center-tapped pots in critical positions of the VCO and VCF, if I remember correctly
I had a response about just this that I must have forgotten to post last night.

The center tapped pots have always been a hurdle for repairing these, or building accurate clones. however I think these days if someone made a nice module it would be fairly cheap to meet the minimum order for some OK quality center tapped pots off alibaba.

User avatar
megaohm
Super Deluxe Wiggler
Posts: 1902
Joined: Mon Jun 15, 2009 6:11 am
Location: Chicago, IL

Post by megaohm » Wed Nov 06, 2019 5:56 pm

Bourns and BI Tech/TTE currently make center tapped pots. Both are legit companies with good reputations.
Contact BI Tech if you need to special order. Their min quantities are usually low (maybe a couple hundred), inexpensive, and better quality than most
(conductive plastic, 100,000 rotations rating).

Bourns - PTT111

BI Tech/TTElectronics - P09x series
meatcliff wrote:
fluxmonkey wrote:another hurdle would be the center-tapped pots in critical positions of the VCO and VCF, if I remember correctly
I had a response about just this that I must have forgotten to post last night.

The center tapped pots have always been a hurdle for repairing these, or building accurate clones. however I think these days if someone made a nice module it would be fairly cheap to meet the minimum order for some OK quality center tapped pots off alibaba.
www.MegaOhmAudio.com

Will work for pistachios

User avatar
sanders
Veteran Wiggler
Posts: 738
Joined: Tue Feb 03, 2009 4:42 pm

Re: Is anyone working towards an EML 100/200 clone?

Post by sanders » Tue Mar 10, 2020 4:29 pm

8C204A2A-C5BE-4262-9566-AFC8D84B5729.jpeg
Well, I guess someone actually is doing a 1:1 EML 200 clone, although there’s almost no info here, just sone very enticing photos:

http://www.hellectro.com/
4186D992-0896-40D2-AF63-D56649CAA59A.jpeg
B42DBFE7-E221-4F53-AD31-EECC6D188322.jpeg
You do not have the required permissions to view the files attached to this post.

Post Reply

Return to “Music Tech DIY”