[sdiy] frequency counter

[JWBarlow at aol.com]

I think there are a lot of people that use Mike's way of calibrating VCOs.  
this is the way I do it with one minor addition. 
 
The last time I did it I know I found using a divider made it much  easier to 
get the whole range for the VCO. I know why it made it easier. It's  because 
it is very hard to discern pitches which are more than 5 octaves apart.  I 
can't exactly remember how I used it though <ouch!>. I'm hoping someone  who has 
used this will chime in here.
 
John B.
 
 
 
In a message dated 6/25/2004 7:29:37 PM Pacific Daylight Time,  
WeAreAs1 at aol.com writes:

In a  message dated 6/25/04 6:49:01 PM, mark-romberg at utulsa.edu  writes:

<< anyone know of a simple-ish frequency counter  circuit?  beginning to 
realize im going to need one to tune  oscillators and things in the 
analog world as i dont have perfect pitch :/  >>

Mark,

For tuning VCO's, a guitar tuner is much more  useful than a frequency 
counter.  I prefer tuners that have an analog  (VU meter) readout, such as 
the BOSS 
TU-12H.  You can easily pick one  up for about $40 to $50 on Ebay.  A 
mechanical 
strobe tuner is good,  too, but kind of overkill for the app.  I've been 
working  professionally on synths for over 25 years; my standards for musical 
 
perfection are very high, and I would NEVER tune a VCO with a frequency  
counter.  It 
just doesn't work.  I'm sure others might argue  otherwise.  Let them.

Michael Bacich

BTW - the preferred  method for tuning a multi-oscillator synth is to tune 
just ONE oscillator  using the tuner.  Get the scaling, octaves, hi-frequency 
tracking,  and offset as close as you can (according to the tuner), then tune 
all 
of  the other oscillators to that first oscillator.  If you use the tuner on  
all 
your VCO's, it may get close, but it will never be perfect (if you use  a 
frequency counter - good luck!).  This applies especially to  monophonic 
synths 
such as the Minimoog.  On polyphonic synths (the  few that have user-tunable 
VCO's 
and no auto-scaling [not the same thing  as auto-tuning!], such as the OBx, 
OBxa, Jupiter 8, and Jupiter 4), it's  OK to tune the first VCO of each voice 
to 
the tuner, but be sure to then  tune the second VCO of each voice to the 
first 
VCO of the same  voice.  (the rules are different for synths that have 
auto-scaling,  such as the Prophet 5, Jupiter 6, OB8, etc. - most of those 
synths 
require  very little in the way of calibration)




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