Varitone inductor question.

[pjones78]

So fast and easy question. Looking at varitone circuits, instead of using those bulky inductors that look like they came out of wall warts, would these work just as well?
Thanks in advance.

http://www.taydaelectronics.com/catalogsearch/result/?q=inductor

http://www.taydaelectronics.com/15uh-inductor.html

[smallbearelec]

instead of using those bulky inductors that look like they came out of wall warts, would these work just as well?
http://www.taydaelectronics.com/catalogsearch/result/?q=inductor
http://www.taydaelectronics.com/15uh-inductor.html

Those are very small inductances, tens of millihenries tops. A Varitone circuit wants several hundred millihenries. The primary of an audio transformer like this one:

http://smallbear-electronics.mybigcommerce.com/transformer-mouser-42tm019

is popular. High-inductance axial parts are also available, though expensive:

http://smallbear-electronics.mybigcommerce.com/wilco-axial-lead-inductors/

[pjones78]

But this would not be the correct one, right?

[smallbearelec]

But this would not be the correct one, right?

Neither the one you mentioned nor any of the others in that list would be suitable.

[pjones78]

I'm sorry, I didn't specify. The one that you posted, would it work in the circuit?

[idy]

If you want an answer you need to post or link to a schematic. Then we will know if the inductors will work.

[Mark Hammer]

Generally speaking those Mouser interstage transformers provide inductances in the desirable range of 1-1.5 Henries.

The 10M resistors you often see in schematics are to avoid audible popping when switching from cap value to cap value.  The 10M allows the cap to drain off when not connected.

[Granny Gremlin]

Im not sure about the guitar varitone (Lucille etc) but the bass varitone (as used on the EB3 and Ripper) used a humbucking (2 series, air-core, coils, reverse wound to each other) inductor with a value of 30 Henries (that's right, not mH, but H).

The 60s EB3s additionally had this humbucking inductor mounted in a shielded can.  Somewhere after 1971 they gave up on the can - later (Series 2) EB3s and Rippers had exposed coil inductors.

Curtis Novak makes a repro of the Series 2 EB3/Ripper choke - looks identical to the original but I have never used it: http://curtisnovak.com/pickups/EB-Choke.shtml

Looking at the schems for the Lucille varitone and an Series 1 EB3, looks like the inductor has the same part number in both guitar and bass varitones: GA-90[C] (though I have also seen it marked GA-90-1C and TF-90-1C in actual 60s instruments).  Curiously, the Ripper has a completely different part number (same as Series 2 EB3) - I would assume the different part number is due to lack of Faraday shield vs value change, but am not certain.

I can't confirm the inductor value right now, but I remember seeing it on an official Gibson Schem somewhere.

[pjones78]