Hello Nathan,
Apparently I missed your message in october.
I've also had plans to clone the EML200, but I was not able to find the special pots (1M/100K stereopots) that are used in the filters. Did you find them? Some time ago I was able to buy an EML200 so I didn't continue my plans to clone it. To be honest, the filters are not that great, If I was going to clone it I would probably replace them by the EML 101 filters.
But I did study the 200 schematics a bit.
I think that in the schematic of the switch, the MC1445 ic is numbered incorrectly. For example in the schematic the point going to the negative voltage supply is 7, while in the datasheet of the MC1445 ic, 7 is an output and VEE is leg 8 of the ic.
Best regards,
Kris
--- In emlsynth@yahoogroups.com, "nathan.siter" wrote:
>
> Hello,
>
> I realize this is possibly a controversial subject for some of you but I am going to go ahead and post this anyways. A few of you might actually be interested.
>
> I am attempting to build a eml-200 from scratch. I am not doing this for profit but out of my own DIY hobbyist interest. I am also a published musician who just cannot afford to buy the real thing. I figure, once I get started with buying parts and etching my own pcbs, I should be able to do it for well less than half of what they go for on ebay. In addition, I will have an intimate understanding of how the machine works. However, lack of information has forced me to come here and search it out. I am of course willing to share the information and steps I take along the way to people who are interested.
>
> I spoke briefly with George Mattson, who advised to do a complete redesign of the pcb in order to make space for modern components, as he did with his rebuilds. I am also able to add a few mods direct to the circuit board. Basically, I am not interested in a museum clone, but stable modern adaptation of the circuits.
>
> What I am looking for is any pictures people might have of the interior of their 200. I would like to keep the pcb close to the original but of course it is not exactly possible. Also there are some parts on the existing schematics which are not labeled. Nor is the power supply accounted for in the schematics either. So if anyone has some info on those it would be a help. In addition it is quite possible that some of the schematics contain mistakes: either intentional or unedited: as I have heard from people who clone Buchla and EMS gear (this was common practice). This is where high quality pictures might be helpful, so I can compare myself. I have already transferred 98% of the existing schematics to a pcb planning program, which means they are now easier to read. I can certainly post them when they are finished. And I have the the pcbs laid out (1st draft). This took me a few weeks, so I am not looking for "hand outs" or someone else to do work for me, just advice and help when it is convenient.
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> In addition, please do not argue the moral implications of this project with me. I am working with OBSOLETE circuits from a company that has been out of business for 25 years. I am not doing this project to sell this unit but more out of a love for analogue circuitry and synthesis in general. I am sure most of us agree the EML line is highly unique and the prices are out of reach for most people. If you have problems with what I am proposing, please contact me off list, instead of clogging up the community with negative energy, as I am sure some people, even those who dont agree with this project would rather not read it.
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> Thanks for your time and enjoy your originals!
> Nathan Siter
>