Fender 5E series choke

[loudthud]

A question came up on another forum about the choke in the Fender 5Ex amps. These were the amps that had Pi filtering on the main B+ with 16uF on the input side and 2x16uF on the output side. It's been suggested the specs of the choke were 10Hy, 200mA, 125 ohms.

5E4-a Super
5F4 Super
5E6 Bassman
5E7 Bandmaster
5E8 Twin

1) Were these the first Fender amps to use a choke?
2) Was the choke used roughly 3 inches on a side with 4 mounting screws and weighting 4 pounds?
3) Some later schematics specify a choke as 14684. Was this a Triad part? Was it the same as that used in the above amps?
4) Anyone got pictures?

[fyl]

It's been suggested the specs of the choke were 10Hy, 200mA, 125 ohms.

More like 6 to 7H @ 200mA.

Were these the first Fender amps to use a choke?

Some earlier 5D models used a similar arrangement in their late '54 -A versions. Vide for instance the 5D6-A.

Was the choke used roughly 3 inches on a side with 4 mounting screws and weighting 4 pounds?

Open frame, two-point, nearly the size of the OT.

Some later schematics specify a choke as 14684. Was this a Triad part? Was it the same as that used in the above amps?

The Triad 14684 is a lower rated version - 3.5 to 4 H, 35R, 90mA. Some docs spec this choke for 5D and 5E-type amps but I now believe that's a mistake.

Anyone got pictures?

Yup, here's one of a '56 5E7 chassis, with PT, OT and choke. Source unknown.

[loudthud]

Great post FYL !!!

I'd kind of like to get peoples impressions on the differences the Pi filter makes as far as tone is concerned. I'm going to the Dallas Guitar show tomorrow and I'm sure Gerald Weber will offer an opinion.

The Triad C14X seems reasonable. 6Hy 200mA 150ohms. Overall width is 4 inches. I'm kind of curious where that 14684 number came from. The Triad info I can find online doesn't mention anyting close to that number.

It's interesting that in that one brief period almost all of the Fender amps had Pi filters. Even the small models like Champ and Princeton, but they probably used a smaller choke. Many of the larger amps had dual rectifiers.

[fyl]

I'd kind of like to get peoples impressions on the differences the Pi filter makes as far as tone is concerned.

More sag, browner sound, really nice at old-style levels using vintage single coil guitars - works wonders with a twangy Esquire or Tele.

The Triad C14X seems reasonable. 6Hy 200mA 150ohms. Overall width is 4 inches.

The C-14X is a good choice. You may also consider the Hammond 159Q (very conservatively rated at 150 mA and holding inductance at 200 mA and more) and the Weber W014684.

I'm kind of curious where that 14684 number came from. The Triad info I can find online doesn't mention anyting close to that number.

Got it in my docs, but nowhere in vintage catalogs or listings. Could be an OEM part number.

It's interesting that in that one brief period almost all of the Fender amps had Pi filters. Even the small models like Champ and Princeton, but they probably used a smaller choke. Many of the larger amps had dual rectifiers.

Capacitors were more expensive and less reliable than iron. Dual rectos allow for controlled sag at high currents - they were replaced by new rectos such as the 5AR4, which works as well or better than two 5U4GB's, takes less space, costs less and allows for smaller PT's as well as better thermal management.

[Bruce / Mission Amps]

I use a 5Hy 200ma choke in my 5F4s, 5E5 and 5E7 amps.
It works flawlessly.
Before I broke down and had them custom wound by Heyboer, I used the smaller, Hammond 158Q and that worked very well too.

[nokaster]

an old thread, but the 14684 turned up in my research to build a tremoluc 5G9.

which choke would you guys recommend for a 5G9 build?


thx

[Jag]

Is there anything GW doesn't have an opinion on?

[loudthud]

GW never lacks an opinion and he aint afraid to express it. When refurbing one of those Fender amps with the PI filtering, he moves the OT to the rectifier side cap. He likes the sound that way.

[Wharf-Creek]

Hey, this is my first post on this site, so please forgive me if I already messed up. I am looking at doing a 'clone' of the 5G9, and in doing an internet search on it this thread came up. I see the question about 'what choke?' to use, but I'm also wondering if there are any recommendations as to Output Transformer and possibly power transformer as well? I'm planning on doing a non-tremolo version of the amp, and also being just one channel...though I'm not sure which one yet. May consider having the same 2 inputs, but having one being the 'tone' side and the other being the straight to the VC side. Still thinking about it. Anyway, also wondering if anyone has 'subbed' the 12AY with any other tube, and if so, what additional changes were made to the circuit? Many thanks, WC

[deci belle]

Hi Wharf! I just built a 5G9 using an old chassis that already had the holes for a 5F8a choke. So I just put one of those in it.

Those tweed chokes are often around 3H. The one I have is a LOT higher rated than what loudthud, Bruce and fyl said, though.

The one I'm using is 2.8H, 49Ω, 400mA. It's pretty massive.