[sdiy] PAIA for Appreciation of Heathkits?

[Dave Manley]

Just as a reminder here are the 1972 prices of the 2720 series modules:

VCO $24.95
VCA $12.95
VCF Bandpass $11.95
VCF Low Pass $9.95 <--- $9.95 ???
LFO/Noise $19.95
Power Supply $22.00
Case/Controller  $37.00
Attack/Decay Func Generator $19.95

Total packaged cost for the whole deal $139.

To John's credit in the sales booklet for the synthesizer he says this 
about the filters:  "It may seem strange for a manufacturer to state in 
a sales booklet that his product doesn't have the best technical 
specifications available, but that's what we're doing", and then goes on 
to describe why compromises were made. A little latter the specs for the 
low pass filter are given: "Cut-Off Freq: 50 Hz,  Roll Off Rate: 0 to 12 
db/octave".  Elsewhere he gives the pros and cons of the linear vs. expo 
choice, not using an opamp in the control voltage summers, limited range 
of the filters, tracking problems, why there isn't an ADSR, why no sine 
out on the VCO, etc.  He's clearly not trying to fool anyone about what 
they're going to get.

The booklet itself reminds me of why Paia was so great.  In ten or so 
pages you got the following: a history of electronic music, briefly 
covering the Martinot, Ondioline, Theremin, RCA Mark I & II synthesizers 
and onward to R.A. Moog and the importance of control voltages, an 
overview of acoustics, Fourier analysis (without mentioning Fourier), 
subtractive synthesis,  controller alternatives, and finally the equally 
tempered scale.  If I recall correctly, originally Moog didn't provide 
even a basic users manual for the Mini.  Paia was important (at least to 
me) not because they made a cheap, crappy synthesizer, but because they 
made basic synthesis technology available to anyone with a little bit of 
motivation, and backed it up with reasonably good documentation and 
customer service.

One of these days I'll have to dig my old 2720 modules out of the box 
they've been in for 20+ years and see how bad they really were ;-)

-Dave

>>> you get a design that is at least marginally
>>> functional... but missing many of the components that
>>> guarantee robust performance over a wide range of
>>> component and environmental variations.
>>>
>>>       
>> I don't think high performance was ever a PAIA design goal. I think John Simonton was aiming to get something functional at a price where high school kids could afford it. Performance was definitely secondary to low price. The low price made it so you could modify the snot of of them without worrying. A great place to start learning electronics.
>>
>> Also remember that in some cases the PAIA units out performed much more expensive commercial gear (the Putney comes to mind). And the worst PAIA VCOs are still more stable than a violin.
>>
>> That 27xx low pass filter was awful though. I remember being so disappointed I almost gave up on synthesizers.
>>
>>     
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