a link to mouser for a small signal tranny that is good for 20H
of inductance with all windings in series.
 
it is very small and it is <2 bucks. there is only one requirement--no
DC through the coil. when placed in series with a cap, that's not a
problem anyway.
 
mouser part numbers, and inductance w/all windings in series:
42tm025 = 20H
42tl024 = 6H
42tm019 = 13H
 
gyrators are handy and CAN be just what the doctor ordered, but
having two leads and a small core to hot-glue somewhere is even
easier, and thus much preferred by lazy slobs like me. 
 
ken
http://www.mouser.com/products/detail.cfm?mpart=42TM025&CustRef=&source=search&CFID=16227569&CFTOKEN=17684864


Below the node where the cathode R and the cap bypass for it
would normally go to ground, there is a resistor going to ground,
5k, a spst switch going to ground to by pass the resonator, paralled
by a 10 k pot whose two ends are at cathode reisistor and at
ground, and coming from the pot wiper a 4.47 H choke with
internal r of 74 ohms, and then a cap, which I have varied from .47
to 2.2 ufd, my notes don't say where it is now. The other end of the
cap is tagged to ground.
 
For a bass, this produces a really danceable pump, if your rig is up
to it, and it neatly counter balances the typical over damped low Q
bass speaker.
 
I find it easy to get a handle on eq in general by feeding a square
wave through the circuit of interest and seeing how it mutates.
Leading edge is treble, trailing edge is bass.
 
Dan