DIY subsonic filter anyone?

[BobM]

Anyone construct a DIY subsonic filter to get rid of the woofer pumping action when playing vinyl? A few questionsI have on a project like this:

(1) I assume it might go between the preamp and the amp, and would therefore need fairly high grade components to be inaudible (but could it go in the phono preamp??? - a far better location for me)

(2) It would need a switch to be active or bypassed

(3) I don't have a clue on the components needed or a schematic for this

Thanks,
Bob

 

[Keld]

http://sound.westhost.com/project99.htm

 

[sam9]

How about a 1 or 2uF film cap in series on the preamp or amp input. I recall some 70's gear that touted a "rumble filter" that was no more than that. You probably want to switch it out when paying CD's. If you can modify your preamp you could put only on the pono input, then you wouldn't need to switch it (unless your LP include some old Telarc's or Vigil Fox D2D's.)

 

[jackinnj]

link to ADI

here's the Analog Devices online filter design software -- just choose an F3 of 16Hz or so:
http://www.analog.com/Analog_Root/static/techsupport/designtools/interactiveTools/filter/filter.html

 

[jackinnj]

and you get a nice magnitude/phase plot