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High Pass Filter

Started by bent, September 15, 2010, 04:24:16 PM

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bent

Hello,

I'm searching a high pass filter for microphone that will affect the 90hz frequency, like the TL Audio Ivory 5052 have:
http://www.tlaudio.co.uk/docs/about/pdf_manuals/ivory_2/5052_Mk-2_manual.pdf

It's say's:
4.6 90Hz Filter.
The high pass filter switch restricts the low frequency response of the preamp, to
effectively remove rumble or LF noise from the signal. The filter can be useful in
restricting "popping" on vocals or even low frequencies caused by contact with
microphone stands or microphone cables. Popping is an undesirable thump that is
caused by close-miking certain spoken or sung letters, namely "P" or "B". These
particular letters cause a sudden expulsion of air that can result in an audible thump.
As this thump has a lot of low frequency content the high pass filter can help to
reduce the problem, as can using a pop filter (a device usually made out of nylon
material similar to stockings) suspended in front of the microphone.


Anyone have a complete schematic , cause i found this one on the  forum, but it's not complete (pin out of the lm110?) and dont know if applicable:
http://www.diystompboxes.com/smfforum/index.php?topic=82150.0

thank's

Bent
Long live the music.....

PRR

> (pin out of the lm110?)

LM110 pinout is readily available; Google is your friend.

However: an LM110 (any usual chip) in front of your preamp will increase hiss; an LM110 after your preamp will probably reduce output drive capacity.

The Ivory is a very complicated box and the high-pass filter is incorporated somewhere inside.

The popular path is to capture the music with the thumps, avoiding overload, and then do a high-pass in mixing. Good mixers, and most digital audio tools, have high-pass functions.
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bent

Thank's PRR,

The google search was done before posting, what i mean, is i dont know how to connect the pin 1, 5 and 8, do i leave them unconnected ?

The high pass filter in the ivory is right after the instrument input selector, before the   phase....

bent
Long live the music.....

brett

Hi
RE: spare/undescribed pins
on many single op-amps, there are 2 pins for frequency compensation and 1 that's not connected.  Most of the time, you'll want to leave all 3 unconnected. The datasheet should discuss or demonstrate this.  In a few rare cases (e.g. the LM308 in the Rat) a small capcitor is used for frequency compensationor some such.
cheers
Brett Robinson
Let a hundred flowers bloom, let a hundred schools of thought contend. (Mao Zedong)