[sdiy] Cheap frequency counter for oscillator calibration

[Magnus Danielson]

On 04/22/2010 08:36 PM, thx1138 wrote:
> On 4/22/10 9:46 AM, "Adam Schabtach"<lists at studionebula.com>  wrote:
>
>>> Hi Guys,
>>>
>>> Just for fun, Ever try using a tuning fork and your ears? It is a bit of a
>>> work but the voicing is so much better on a piano.
>>>
>>> I use a Peterson Strobe tuner that I have had for about 30 years and it
>>> performs very nicely. I usually set the end to end v/0ctave to be exact as
>>> possible using a 4 1/2 digit DMM. And make sure octave switches are not
>>> throwing any offset voltages into the tracking.
>>>
>>> Freq counter, it is possible but pretty sterile sounding results in my
>>> opinion.
>>>
>>> I guess it is a curse to have perfect pitch sometimes.
>>>
>>> Just my 2 cents.
>>>
>>> Regards,
>>>
>>> Terry
>>>
>>
>> Hi Terry,
>>
>> Do you have any opinions as to why the results obtained with a frequency
>> counter are "pretty sterile sounding" when compared to the results obtained
>> with a strobe tuner? It's not that I don't believe you, but it seems odd to
>> me that there would be a difference.
>>
>> --Adam
>>
>>
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> Hi Adam,
>
>  From my experience at Oberheim and E-Mu I tried the Freq. Counter and tuned
> Osc. Without hearing the output and then I listened to the output via
> headphone/speakers and it seemed to loose all warmth. I seemed that if I
> tuned the Osc. By ear the voicing was much more pleasing.
>
> I tuned my piano by using the strobe tuner and the voicing was terrible. The
> difference is sympathetic string interaction vs absolute freq. Setting.
>
> The error in piano is much more pleasing than trying to get the last 2-3
> cents of accuracy in. I would call this the warmth factor. Harold Rhodes at
> Fender demonstrated this to me when I did some work for him back in the
> early '70's.
>
> But the 83 milivolts per note is a given and 1 v/octave needs to be set
> correctly or you will go sharp or flat up and down the keyboard.
>
> The Prophet V allowed microTuning but I am not sure any other synths did.
> Being I am also a wind player and using a LyriconII as my controller is a
> different issue.

Thus, the trouble you have with tuning with a frequency counter is that 
you can tune it too exact... so you loose some of the off-tuneing 
beating action.

This is not saying that the frequency counter tuning doesn't work, it 
says that it works very well... but the danger is that it may not be 
what you want... to be exact. Thus, for our usage too well tuned 
oscillators is not always what we want.

Considering that the counter is that exact, you could deliberately 
miss-tune it a little from what the scale says and you are home free.

The OB-8 auto-tune certainly makes the machine colder. I only wish it 
had an auto-detune (defrost?) feature to warm it up again. :)

Cheers,
Magnus