Topic: Homebrew attenuators?

[hexyjones]

Would it be difficult to make some mic level attenuators?

Im outfitting a friend with an MD outfit...the mic in has no sensitivity switch.

I did experiment with the line-in and I think I will have him use that for loud shows...

But I would like him to be able to use the mic in at moderate volume-type shows...

What Im looking for is the sonic/electrical eqivalent to the -20db switch on the old Sony D5 Cassette recorders...I'd be happy with whatever that is...electrically speaking.

This would be for an unbalanced connection...

Im hoping this is something that I can build into a cable...or small box if necessary.

I did a bit of searching - but nothing too concrete...

[Todd R]

I did this awhile ago when I was running km184s and a Beyer MV100 since the 184s would be too hot for the beyer and it would overload even when set to its lowest 20db gain.  So I built a set of -10db attenutor XLR cables.

I used a U-pad configuration.  Some info on various attenuator pads can be found here:
http://www.uneeda-audio.com/pads/

The U-pad is the topmost pad shown on the right hand side -- for balanced connections.  For unbalanced you'd want the L-pad configuration. 

I'd use 1% tolerance metal film resistors (available at radioshack) for this project.  So for a -20db attenuator for a balanced cable, you'd want a 680 ohm resistor in series on each of the signal lines (pins 2 and 3), and then a 150 ohm resistor between the two signal lines (pins 2 and 3).

I'm not sure what values of resistors you'd want to do an unbalanced L-pad.  The webpage above might help you determine that, or you can try doing a search on "L pad attenuator".  Good luck!

[hexyjones]

Wow - great article...lots of good info there - plus good stuff above and beyond the topic at hand.

and thanks for the search tip...that helped alot...i didn't really know what to call it...

Thanks!