[sdiy] Boards for a parametric EQ?

[yves usson]

Hi

If you look thorougly to the schematics you'll see that the frequency 
dual gang pot
is label 100K R.A. where I gess R.A. means reverse audio (that is 
reverse log) which
is perfectly compatible with the log scale on the front panel.

Cheers

Yves

Andre Majorel a écrit :
> On 2008-09-12 11:16 +0200, ChristianH wrote:
>> On Fri, 12 Sep 2008 10:54:26 +0200 Andre Majorel <aym-htnys at teaser.fr> wrote:
>>
>>> Just saw the Moog three band parametric EQ schematics :
>>>
>>>   http://files.muziq.be/schematics/moog_pareq.jpg
>>>
>>> The frequency controls are dual gang 100 k pots used as variable
>>> resistors. The schematics do not say "log" or "anti-log" which
>>> implies they're linear. And yet the angle-frequency relationship
>>> is exponential :
>>>
>>>   http://www.scale.gs/MoogParaEQ00.jpg
>>>
>>> Is this possible ?
>> Well, in the Mini schematics, all the mixer level pots don't have a
>> specific log marking either. May be they implied log where it's kind of
>> obvious? I mean, audio level pots are usually the prime example for
>> using log pots.
> 
> Yeah, thought of that but the "width" (Q) pots are duly labelled
> "AUD" so...
> 
> « ... and this year's Most Productive Employee Award goes to
> Irving C. Saltzberg Jnr who saved no less than EIGH-TY SE-EVEN
> SECONDS by skipping the LIN and LOG suffixes in his drawings. »
> 


-- 
Yves Usson

Lab. TIMC UMR5525 CNRS
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email : yves.usson at imag.fr, yves.usson at ujf-grenoble.fr

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