FX Loop in Fender Showman?

[gregsk777]

Hey everyone,

I have an old beat up Dual Showman that has been my main amp over the years. For some reason it has two holes in the back of the chassis and I was wondering if it is possible to add a FX loop?

I found this showing how two pre-amp outs could be wired in a Fender:


Would I need to just wire some kind of power amp in and stick a EQ pedal in the middle and vuala? Or would there need to be somekind of tube buffering or something more elaborate to get a FX loop working?

Thanks

[imaradiostar]

A showman is generally used clean or mostly clean and isn't known for its preamp distortion. You might not find there is much benefit to a loop on a showman.

jamie

[deci belle]

You'd have to borrow a tube from your other channel and/or the vibrato. The Torres book explains different ways to do it.

[Chuck H]

Right and +1 to the above posts. The Showman is generally a clean amp. If your using it that way you should do fine running pedals into the input. If you must have an effects loop you'll need to pilfer a triode from the amp somewhere that doesn't affect the channel you use. A "preamp out/power amp in" won't be compatible with many effects and probably none of the digital effects processors. A proper effects loop should be padded to about 1VAC output and then reamplified post effect to the pre padded level. Low impedance output for the loop is a general rule but by the time you pad the late preamp signal to 1VAC the impedance will likely be low enough not to be an issue unless you want to run very long cables.

So, how are you using the amp (which channel, etc)? And, why do you need an effects loop?

[gregsk777]

Thanks for the input. I was just looking to run an EQ pedal after the preamp to get more tonal variety. I had a JCM 900 SL-X that sounded good but by sticking a EQ pedal in the FX loop it just sounded amazing and allowing me to shape the tone better. I was just looking to recreate something like that I guess.

I did however hook up a preamp out and power amp in right before the phase inverter input cap and so far it doesn't sound too bad at all if I stick an EQ or pedal in the loop. Doesn't sound like any signal is lost?

[Chuck H]

My old Boss GE-7 worked fine for me with a Marshall 1987 that was modded with a preamp out/power amp in. But I was unable to use processors with that amp also. If you don't run long cables it should be fine with what you propose.

[gregsk777]

Yeah I plan on just using two patch cords with my EQ pedal sitting on my amp so there should be no long runs. It's no perfect setup but much easier than trying to figure out how to install a real tube fx loop. If I don't need it I just stick a patch cord between the two jacks and my amps sounds back to normal again.

A conversion of the normal channel into an fx loop would sound interesting since I never use that channel?

[J M Fahey]

I had a JCM 900 SL-X that sounded good but by sticking a EQ pedal in the FX loop it just sounded amazing and allowing me to shape the tone better. I was just looking to recreate something like that I guess.

JCM900s have SS preamps and/or derive their distortion from clipping diodes, which implies their distorted signals are pedal-friendly and effects loops are easy to add. Well, in fact, they already have them.
Classic Fenders have Guitar level signals (what a floor pedal is designed for) only at their input jacks and that's the point where pedals should be hooked.
Amplifying signal 100X , padding it to original level , processing it and the re-amplifying it 100X again sounds kind of futile to me, specially since the re-amplifying triode, in essence, is the same as the original input triode so, what have you accomplished?
In fact all you do is *still* hook the pedal up front, only the signal driving it previously went through a (clean) triode and then was padded to original level.
I very much doubt I could hear *any* difference .