Starter help needed

Posted: 1/27/2014 9:05:55 PM
Ambugaton

From: Volos, Greece

Joined: 1/27/2014

Hello theremin people!

I'm new to this site and generally to the theremin things. Recently though, i got a project for my university and i chose to build a theremin based on a fast reasearch i had made on the internet and the fact that i always wanted to make one for myself. :)

First of, i prefer a model that has both pitch and volume antenae. Secondly, it would be easier for me to find a kit. I'm making this on a budget, so something like the moog models are way over me.

I decided to go for the jaycar model which i saw with some modification on the box can be made pretty neat, but i just found out that it's out of stock in all the sites i looked. Can you suggest me where to buy one such kit online, or otherwise tell me what do i need to get so i have something equivalent to the jaycar both in quality and moneywise?

Take into consideration that my skills with electronics are limited, but part of the project is to learn something in that field so i'm willing to try things.

Thanks in advance. :)

Posted: 1/28/2014 2:11:18 AM
FredM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as WaveCrafter.com . ...................................

Joined: 12/7/2007

 Hi Ambugaton - welcome to TW!

You could try the EPE UK site - Dont know where in the world you are, but they do ship to the USA and other places..

http://www.epe-magazine.co.uk/shopdoor.html

Search for theremin, IMO probably the best theremin they did was in 2008, and was based on the SC / Jaycar designs.. I believe they did one in 2011 as well, but I never bothered to examine this..

They dont supply kits (AFAIK) , but they do supply circuit boards and you can buy a download of the magazines in which the projects were published (or perhaps even just the project - im not sure).

You could also email them if you need a board no longer on the lists - The 2008 theremin boards had a fault (wrongly laid track on the volume circuit - easy to fix when you know about it) and they may have some of these in a bin somewhere if they dont have any corrected 2008 boards on sale now. (looks like they dont)

Fred.

The S/C board is quite simple to make or track on round-pad board - see all references to Enkelaar theremin on this page.. But it is damn annoying that you cant buy the kit, as it makes life much easier.. May be worth your while contacting Jaycar to see if / when they expect these back in stock again.. Or if you can buy a PCB from them.... They may be having supply problems on some component (IFT transformers for example) which you could get elsewhere (I have loads and would happily supply some - they are the parts used in this theremin and I bought them from Jaycar - I notice they dont sell these seperately anymore.. I dont like their IFTs, the Xicon ones from Mouser are mechanically superior IMO)

pps.. It may be worth contacting someone here who is building the EM / EW theremin or clone thereof - Some folks are doing PCB layouts, and if you club together you will gain some economies of scale if you share PCB and component costs.. The EM is a FAR superior theremin - and not highly expensive if you build it your self (perhaps 30% of the retail Moog EW kit price)

 

Posted: 1/28/2014 11:58:46 AM
Ambugaton

From: Volos, Greece

Joined: 1/27/2014

Thank you very much Fred.

I already emailed jaycar and a couple of other e-store sites that may still have the jaycar model and i'm awaiting for replies. The EPE magazine is a very intresting solution, i guess i can get quite a few knowledge points from their issue (there is a 2011 edition i expect the problem you're refering to, to be corrected there). I'll order that soon too.

Thanks again and i'll bother you again when more problems arrive (which i know they will ;) )

Oh and i'm from Greece, just to get to know us better hehe.

 

Posted: 1/28/2014 9:31:18 PM
FredM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as WaveCrafter.com . ...................................

Joined: 12/7/2007

Hi again Ambugaton,

Just FYI - I dont think the EPE 2011 is at all similar to the 2008.. I have never seen it or schematics for it, but have a recloection that it might have been pitch-only.

The EPE 2008 is a bit of a mess design wise - apart from the PCB error (which is really minor) A antenna equalizing inductor was added, but its not good - the SC circuit on which the theremin was based really isnt suitable for antenna equalization..

That said, with a bit of care in tuning, and paricularly if you replace the inductor with a better Bourns one, you can get some linearity improvement over the standard SC models - problems only occur if you push the tuning too far towards optimum linearity, at which point the bloody thing crashes.

Setting this theremin up is horrible - once its set though, it works well for its price / simplicity... But I really only suggested it because the Jaycars arent available - The Jaycar kits are far simpler, and setting up is far easier.

Fred.

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