Mid Control For Fender E-Series?

Daver · 03-17-2007, 05:16 PM

Has anyone been successful at adding a mid control to the tone stack or somewhere else in the preamp of a Fender E-Series type amp? I'm referring to the tweed 5E5A, 5E7, etc. Thanks.
Daver

Ray Ivers · 03-19-2007, 01:45 PM

Daver,

Assuming you don't want to use an inductor (as I would do), the 5E7 circuit looks like it might be a good candidate for a T-filter. The 10M feedback resistor around the 2nd tube could be split into two 4.7M's, with a cap/pot to ground from their junction (this would be mid boost-only).

Oh, yes - my answer to your question is "no, not me".

Ray

Daver · 03-20-2007, 01:22 AM

Ray,
Well, I'm not against using an inductor. Something simple has its charm, too.

What about a T-filter following the tone stack? I've seen fixed versions in some Gibson amps and an adjustable Mid control version in the Matchless Chieftain. The E-series is mid rich as it is, so boosting it only doesn't appeal to me much. I appreciate the interest and help!
Dave

Ray Ivers · 03-20-2007, 03:51 AM

Dave,

I guess I made another assumption too - that you're not looking for garden variety Fender-tone-stack mid control performance - otherwise you could just throw in a 6G16 stack and be done with it.

Assuming that maybe 6-8dB (at a guess) of fairly wideband mid cut would be acceptable, you could bypass the 56K feedback resistor with an LRC network; my wild-ass guess would be 27K/1H/.33uF, something like that. I've found it pretty difficult to source affordable, reasonably-sized shielded/toroidal inductors above 1H, so in this mostly high-impedance circuit you'll be limited in available frequency range and/or cut bandwidth; of course, if you re-ranged all the NFB-related components the situation could be quite different.

If I was limited to a single mid control, I'd personally rather have a 400Hz-centered one with non-ideal bandpass characteristics than a 2kHz one with my "ideal" BP, but YMMV.

Ray

03-17-2007, 05:16 PM	#1
Daver Senior Member Join Date: May 2006 Location: Milwaukee Posts: 196	Mid Control For Fender E-Series? Has anyone been successful at adding a mid control to the tone stack or somewhere else in the preamp of a Fender E-Series type amp? I'm referring to the tweed 5E5A, 5E7, etc. Thanks. Daver

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Laney AOR Series II mod, fx loop, AOR gain	mcrazy4fx	Mods & Tweeks	12	04-08-2008 04:03 PM
Presence Control in Fender Princeton	Richard	Mods & Tweeks	2	11-11-2006 10:13 AM
Mesa MK series schemes, inaccuracies, anybody know?	Joe N	Theory & Design	4	10-20-2006 04:08 AM
Parallel vs. series vs. one filter cap	Chris333	Theory & Design	4	08-29-2006 07:03 PM
Only a series of tests, please ignore.	Rob S	Lobby	7	06-30-2006 09:26 PM

03-19-2007, 01:45 PM	#2
Ray Ivers Lifetime Member Join Date: Jun 2006 Location: Connecticut Posts: 442	Daver, Assuming you don't want to use an inductor (as I would do), the 5E7 circuit looks like it might be a good candidate for a T-filter. The 10M feedback resistor around the 2nd tube could be split into two 4.7M's, with a cap/pot to ground from their junction (this would be mid boost-only). Oh, yes - my answer to your question is "no, not me". Ray

03-20-2007, 01:22 AM	#3
Daver Senior Member Join Date: May 2006 Location: Milwaukee Posts: 196	Ray, Well, I'm not against using an inductor. Something simple has its charm, too. What about a T-filter following the tone stack? I've seen fixed versions in some Gibson amps and an adjustable Mid control version in the Matchless Chieftain. The E-series is mid rich as it is, so boosting it only doesn't appeal to me much. I appreciate the interest and help! Dave

03-20-2007, 03:51 AM	#4
Ray Ivers Lifetime Member Join Date: Jun 2006 Location: Connecticut Posts: 442	Dave, I guess I made another assumption too - that you're not looking for garden variety Fender-tone-stack mid control performance - otherwise you could just throw in a 6G16 stack and be done with it. Assuming that maybe 6-8dB (at a guess) of fairly wideband mid cut would be acceptable, you could bypass the 56K feedback resistor with an LRC network; my wild-ass guess would be 27K/1H/.33uF, something like that. I've found it pretty difficult to source affordable, reasonably-sized shielded/toroidal inductors above 1H, so in this mostly high-impedance circuit you'll be limited in available frequency range and/or cut bandwidth; of course, if you re-ranged all the NFB-related components the situation could be quite different. If I was limited to a single mid control, I'd personally rather have a 400Hz-centered one with non-ideal bandpass characteristics than a 2kHz one with my "ideal" BP, but YMMV. Ray

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)