Adding Effects loop to 5E3

[russmanr]

Hi there,

I just built a Weber 5E3x2 and I'm trying to get a good
sounding delay out of this amp when it's cranked up.
Would adding an effects loop help at all? If so, would
you have a schematic?

Thanks!

[tubeswell]

There's some FX loop schematics on blueguitar.org

I had a similar query a couple of months ago, but didn't get much interest in it, so the best I can offer is my own theoretical response.

I think the simplest way (i.e.; without having to add any gain stages) is to insert a switching jack for the FX return, and a normal jack for the FX send, somewhere before the driver stage of the PI (where you have a separate Driver stage and a separate Inverter stage, such as in a cathodyne- or concertina-type PI), or just plain before the PI (if it is a PI where the Driver and Inverter stages are one and the same, such as a Paraphrase- or LTP-type PI).

I think the switching jack would be wired so that when it is unplugged the FX loop is 'bypassed' by the normal signal path (which in turn is 'cut' when plug is inserted into the FX return jack). The FX send jack just taps off the signal path. You would also probably need a couple of DC blocking caps, one before the FX send jack and one after the FX return jack, as well as a 1M to ground somewhere (i.e.; either before or after?) the FX Loop, to reference the FX loop signal back to the correct grid bias voltage of the subsequent stage.

[tubeswell]

I should add (cos I'm having trouble with editing my posts lately) that I was assuming a push-pull type output stage in the above examples. If its an SE amp, I think you'd add the loop before the final driver stage.

[pdf64]

You need to think about
1/ the functionality of an effect loop
2/ the signal level and the source impedance at the various points in the amp's circuit

Re 1, what is preventing you getting a good sounding delay now?
Re 2, is your delay a stomp box or a pro audio rack type unit? The 2 types accept and put out very different signal levels?

Peter.

[Steve Conner]

Why would you want an FX loop on a 5E3?! It's like putting spinner rims on a Model T Ford. When you crank a 5E3, everything is distorting: the PI, the power tubes, even the speaker is flapping so hard it's in danger of ripping. (When Neil Young is on tour, he has to get it reconed weekly.) I don't see how you could change any aspect of this without losing the 5E3's mojo.

So no matter what you do, your delays are probably going to get dirtied up too. If I was your guitar tech, I'd connect a DI box across the 5E3's speaker terminals, and put the signal from this into a stereo rackmount delay unit, driving a stereo power amp and two more 1x12" speaker cabinets either side of the stage.

If you really want to do it, then bear in mind that the levels in tube circuits aren't really compatible with either stompboxes or rackmounts. The voltages are too high and the impedances are wrong. Rackmounts in particular often have 10k input impedance, and you just can't drive that off a 12AX7's plate.

http://www.diyguitaramp.com/fxloop.html is an example of the kind of circuit you'd need to splice into your amp. Note that you're basically attenuating the signal by a factor of 10, sending it out to your FX, then amplifying it by 10 again. Also that guy seems to think the schematic symbol for a capacitor is an M&M.

[russmanr]

Maybe I should consider alternatives

Thanks to everyone for your suggestions!

I certainly don't want to ruin the soul of the amp, so maybe
I should ask if anyone uses time-based effects with their
5E3. I seem to get that dirtied up, unpleasant delay sound that
Steve alluded to.

I have a TC Electronics G-System that works well in my Mesa Boogie
Lonestar FX Loop. Are you laughing now at the thought of a 5E3
with a G-system? I'm really an old-school guy.. honest! I only
use it sparingly and the delays and reverbs are great.

Anyways, I would consider other options if you have a setup that
works well for you. Steve's suggestion of the DI box sounds like
it indeed would work best, but is a bit costly for my scenario.

Thanks again!!

[Steve Conner]

Oh, well why not play through both amps at once and set the Lonestar/G-System thing up so that it only gives the wet signal, while your 5E3 does the dry.

[russmanr]

how would that get wired up?

is it just a split signal from the guitar into each of the amps?

[Steve Conner]

Yeah, I guess, use some kind of splitter box to plug your guitar into both amps. Hum from ground loops can sometimes be a problem if you do that.

If you're feeling adventurous, you could unplug the Lonestar effects send from the G-system, and use a DI box to feed the 5E3's speaker output into the G-system instead, so you're basically using the Lonestar as a power amp in a mono version of what I originally suggested.

[russmanr]

works well

I dug up an old chorus pedal that has 2 outputs and used it
to send 1 to my Lonestar with effects (wet signal), and the other
straight to the 5E3. That works quite well, actually! Thanks
again for your suggestions.

I'm still interested in what delay-style effects others are using
with their 5E3.

[pdf64]

With any amp that's being driven into power amp overload, effects are going to get mushed up. Often that's fine, wahs, flangers, chorus can sound great like that, but delays and reverbs usually need to be kept clean. In that case, best to stick a mic in front of amp speaker and send the mic signal into the effect unit, set for totally wet, and put it out through the foldback / PA. If the effect and PA is stereo, even better. The dry sound is totally uncorrupted, and the echoes etc will blossom out around you. Peter.

[cminor9]

Not much of an effects guy here; I have commercial amps with effects loops that I have never even used. I guess I just don't "get" effects loops; I always found them worthless. That said, I have put a delay in front of my 5E3 (as in a boss pedal plugged into the input jack). I never really ran the amp at full bore with the delay, but at halfway up and therefore pretty dirty it sounded fine.

Not sure how it'd sound running all the way open. But then again if you run your 5E3 at full bore, I gotta ask what kind of band do you play with? A deaf one?

[teleamp]

A local here use a GT-8 with a 5E3 and it sounds great.

[rickdog]

If your 5E3 has two sets of input jacks, one for each channel, or in your case, you have two amps and two sets? anyway, use the extra jack from the channel you plug the axe into to patch to a reverb pedal or device. send the return to the input of the other channel.

This works great, you can control the level of the effected channel by the volume and keep it clean while keeping the dry signal in the other channel. you can mix it to your preference. this works really well with two channel marshall clones like the 18W TMB also which is where I have tried it the most, but it should work with any amp with dual channels and two pairs of inputs.

[Keith Cary]

On my 5E3 I use a second channel (actually a third.... I built it with three channels because I usually have two instruments plugged in.) to accept my reverb pedal. I built my first channel with parallel inputs, separated by 100K ohm resistors, similar to the Tolex-era Fenders. I plug into channel one with my steel guitar, come out of the second jack to feed the reverb pedal, and plug the out of the pedal into my extra channel. The 100K resistors serve to separate the input of the pedal a little to help prevent loading, in case the input of the pedal is too low. I think 220K would be even better. --- I turn the pedal all the way up both on "level" and on "sustain" and use the pot on the amp to control reverb, like on a regular Fender. The difference has been big for me. Before, when I was using the pedal in-line, in series with my guitar, I felt I could hear it even when it was turn off. It made my steel sound a little deader, lacking snap. Also, when the pedal had a bad connection I lost all my signal. It happened at an important gig and was bad bad bad. Lastly, I think because the pedal is turned all the way up and the amp effect channel is turned down it sounds real. I don't hear that digital stairstep distortion on decay that I just can't stand. Sometimes I find myself being careful not to kick the pedal because I don't want to hear the sproinnnggg sound that happens when you kick a Fender reverb. Old habits. ---- One thing to remember about some, if not all, Fender tweed amps is that the two inputs on, say, channel one, are not parallel like on a black Fender. Each has its own tube stage. You have to actually build the inputs like on a blackface to get this to work. ---- Yeah, I guess the reverb gets distorted as the amp gets distorted, but for my sound it's fine. I usually don't use reverb when I'm up in the distortion zone.
Keith