Diy Battery Module

[MontyJay]

Hey guys...Since I suffered from the dreaded Sharp UTOC errors, I was kinda away from recording for awhile but I'm just getting back into it. I've got a Sharp DR77 right now and a new set of Sound Pro mics on the way, but I also recently found a box of some old mics/battery boxes.

I never finished these up and I thought I would have a go since my soldering technique is about 1,0000 times better than before

Anyway, has anyone else here built their own battery module with bass rolloff? If so, what value caps for what value rolloff are you using? I've got a couple boxes already built but I don't recall the value caps I used (two caps for two rolloff settings). I'm trying to get a couple values down that would be suitable for everyday nature type recordings to full rock concert situations. Thanks!!

MJ

[A440]

Cut and pasted from the Giant Squid Audio Labs FAQ

( http://www.giant-squid-audio-lab.com/gs/gs-faq.htm )

is the following equation for bass roll-off:

Here is a mathematical formula for figuring out what kind of roll you will get with different capacitors.

1/(6.28318 x Farad of the capacitor x Ohm of the recorder's input) = starting point of roll off.

The capacitors we use are .068 micorfarad.

Maybe you know what it means.....

[LowMach]

I attached a spreadsheet I got from taperssection that will help you figure out the cap values needed.

Rolloff_calculator.zip

[kuba]

1/(6.28318 x Farad of the capacitor x Ohm of the recorder's input) = starting point of roll off.

The capacitors we use are .068 micorfarad.

Maybe you know what it means.....

←

Very easy:

1 / ( 2 * pi * C * Z ) = f (in Hz)

so that

C = 1 / ( 2 * pi * f * Z )

Z in Ohms, f in Hertz, C in Farads... You choose the frequency, check the manual for your device's line-in impedance and off you go.

schematics

The resistors are usually 10kOhms