Theremax Pitch CV Response

Posted: 8/15/2012 2:06:34 AM

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 . ...................................

Joined: 12/7/2007

Warning! Anyone who has a working Theremax, and loves their Theremax (or any other PAiA product), is likely to be offended by what I say below. Whilst I feel strongly that what I say below is true, it is all, nonetheless only MY PERSONAL OPINION.

The story I have heard about PAiA:

PAiA started life as a tax fiddle to fund their hobby, they were hobbyists, and realised that by becoming a company, they could offset all their expenses against tax. In order to qualify for tax relief (as I understand it) they had to have products on sale - so they advertised stuff with no expectation of sales, and were shocked when people bought (their rubbish).

I cannot be sure of the authenticity of this story.

IMO, they started as hobbyists - and thats fine, many good engineers do.. What isnt fine is when they dont move on, stay hobbyists, but for some reason which I fail to understand, lose their hobbyist "status" and get taken seriously.

And, IMO, this is PAiA - A "company" which (from what I have seen) has never put a sound design on the market. Any non-hobbyist (and many hobbyists as well) who is competent in electronics and looks at a schematic of any PAiA product (or at least any that I am aware of) is filled with horror at the utter incompetence of the design - and its not just about "cutting corners" to save cost - often the incompetence actually results in inferior circuits which cost more than an equivalent competent design.

"  still had a small square wave component mixed in which is not pleasing to my ears...  I don't know if I had to do that because there is something wrong with my assembly or not but it will probably cause problems in some other way I have not considered. " - No, there was no fault with your assembly - that circuit is one of the incomprehensibly bad PAiA designs, and is typical of the crap they throw together.. its not about cost.. getting a square wave which doesnt pull down the supply and leak in the mix is easy, and could have been done well at lower cost..

Somewhere back in the TW archives, there are a few postings related to the square wave comparator, in which all the technical people involved in the discussion agreed (a rare event, LOL ;-) that the Theremax was a turd not worth polishing.


Posted: 8/15/2012 3:57:15 AM

From: Small town Missouri on Rt 66

Joined: 2/27/2011

Fred, I'll second everything you have said about PAiA.

The keyboard player in my old band bought one of their analog synthesizers, with a microprocessor control no less.

We all had "Keith Emerson" visions about this beast, but they were swiftly dashed. He could never get it linear over a decent range and it had lots of other issues.

He finally relegated it to just playing bass and bought a Korg.


Posted: 8/15/2012 4:50:48 AM

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 . ...................................

Joined: 12/7/2007

"He could never get it linear over a decent range.." - wOttm

Linearity!? ROFLMAO! - PAiA has never bothered about trivia like linearity or playability or thermal effects or any of this sort of thing..

Keyboards are supposed to have a semitone seperation between keys - Everyone agrees on this (LOL) and even "hobbyist" analogue synths from the 70's like the (quite wonderful for its time) PE Minisonic, went to great lengths to design exponential converters in a way that gave linear musical intervals and didnt detune when the temperature changed by a few degrees.

I would certainly not expect a company which cannot even be bothered to keep keyboard intervals linear (playable), to bother about theremin linearity or playability.

I think I was just lucky - as a young hobbyist I fell in love with the first Moog synth I heard - I wanted one but had absolutely no way to buy one - So I bought copies of the patents and started tinkering.. Much later the PE Minisonic 1 article appeared, and I added elements from this to my prototype.... By the time I saw the first PAiA article, I knew enough to see that the design was crap, so I never wasted time on PAiA or the "Tab" circuits.. It was just luck though.

I have (many years ago) tried to help some friends who foolishly ignored my advice to steer clear of PAiA products, so have had some "hands on" with PAiA crap - but there really isnt anything you can do other than fix construction faults - it simply isnt worth  trying to improve anything as badly designed as every PAiA product I have had the misfortune to waste time on.. The only PAiA 'thing' which interested me slightly was the capacitive sensor on their "Gnome" - the idea was fine - but, as usual, their implementation was crap.


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