TW with Effects loop????

[koffee_iv]

Are there con's to installing an effects loop in the TW circut?

Is it transparent when not in use?

Does being tube buffered make a large difference?

[funkmeblue]

did Ken build any wrecks with an fx loop?

[Jana]

The color of the wire affects tone, it messes up the gain structure. An effects loop doesn't do that.

[jjman]

I’m currently working on this for my pseudo-Express. I verified that the 3rd stage’s clipping causes reverb/delay to not sound right if located before the input. So I’m trying to install a loop between the 3rd and the PI. Serial would have to be padded/buffered down before the send since the signal is so strong there. But I’m gonna go parallel and use a voltage divider (or pot) to send a small amount of the signal to the send. Then the signal after the return needs to be brought up at least somewhat to “compete” with the dry adequately. So I will be using one triode for that.

With wet-only reverb or delay settings on the effects unit(s), no need to worry about the phase cancellation. Other settings (or effects) are in time sync with the dry so cancellation is a problem. (This loop w/b out of phase with the dry due to the single triode.) But I’m gonna flip the phase in the loop with an “input” transformer to avoid any possibility of phase cancellation under any settings or effect types.

I’ve been taking my time testing and implementing it, and doing some reading on impedance and specs of transformers. All other effects sound fine in front but I’d really like to have the option for reverb and/or delay during louder settings. Mine’s not a “clone” so I’m already outside the box. Also have Trem and PPIMV which work nice. Yes, I want it all!

[Ron Worley]

If you search this section of the forum, you will find numerous discussions on this. The general consensus seems to be that it would negatively alter the amp's sound by interrupting the relationship between the preamp and the power section...

I'm not smart enough to fully understand it, but it makes sense- the TW sound is based on how the Power section is pushed (I think). Smarter heads here will know definitively why....

[Kregg]

That tone-a-licious straight forward harmonic power amp charm is what drew me to TW's in the first place. Why ruin the mojo when you can buy a Fender/Marshall type amp?

[v846]

In a Vintage Guitar Magazine article Ken did mention he was contemplating putting an fx loop in a Rocket IIRC, don't know if he actually did it though

[benoit]

The other thing you could do is mic your cab, use a small mixer to apply your effects, and run the output to a powered monitor.

[Normster]

Are there con's to installing an effects loop in the TW circut?

Is it transparent when not in use?

Does being tube buffered make a large difference?

There may be consensus that a loop is not a good idea, but I'm not so sure there has been a lot of experimentation.

It would be pretty easy to run two sheilded wires to the back of the chassis and connect them to a temporary "loop box" of some sort. That way you could find out if the extra wiring changes the tone without drilling the chassis.

If all is well, maybe consider an Ironsounds loop. (You could also build a tube buffered loop but that's up to you.) Either way, the preamp signal has to be buffered to keep your effects from clipping.

[pureoldsound]

Not an expert but, that 3rd gain stage is what makes the express what it is. IMHO if I were to add an effect loop on that amp would not be btw the 3rd gain stage and PI as I think it will overdistort the sound. I think it be better off btw the second and 3rd stage. That said what would I do for power tube saturation? SInce this amp is dependant to power tube saturation.

[CaseyJones]

The other thing you could do is mic your cab, use a small mixer to apply your effects, and run the output to a powered monitor.

If you're Neil Young, maybe?

How does that differ from mic'ing the amp to the mains, adding effects and then have effects in foldback? Although, you're right... that's generally not what the monitors are for.

[RJ Guitars]

I am still Expressless... so I haven't got anything to experiment with... but, Derek Ferwerda explained to me that Ken Fischer believed that a well made guitar has built in natural reverb, and an external reverb wasn't needed. The addition of a reverb unit was just to compensate for something missing.

I won't claim to live on one side of the fence or the other on this topic, but I am curious if anyone hears that natural reverb in their Trainwreck?

Now to look at Koffee's query about adding one, I'm with Normster. try it and see what happens. Worst thing that can come of it is you'll know something you didn't and you can always plug the holes and your back to where you started.

rj

[bcmatt]

Also, if you are worried about the holes in the Chassis, remove a speaker jack and put a TRS (stereo) 1/4" jack in there for the effects loop. I did this on my JCM800 clone. Then you just use a single stereo to 2 mono 1/4" y cable. I did a simple interrupt style loop, but I did run into the effects clipping because I didn't buffer (but at least I didn't compromise the circuit-besides several extra inches of shielded cable).

[Firestorm]

I'm fascinated by this from jjman:

"I verified that the 3rd stage’s clipping causes reverb/delay to not sound right if located before the input."

I'm too old-school to use a scope (yet), but I always suspected the third stage clipped a bit. jjman, have you got data, traces, anything to look at?

As to the loop questions, I've always felt a loop should be buffered, inserted right before the PI, and be gain neutral.

A reverb is usually a different thing. Fender always took it off the tone recovery amp and added a mix stage to get it back in. But the best reverb I ever heard was done by Mike Holland -- he tapped the FIRST gain stage, did all the usual things, and returned to the input of the tone stack (basically the same place it was tapped from). He was a great builder, btw, I wish he would get back in the game.

[Normster]

...a well made guitar has built in natural reverb, and an external reverb wasn't needed. The addition of a reverb unit was just to compensate for something missing.

As a former reverb addict, I can attest to this. When I stopped using reverb (or at least reduced the amount that I used) I found that I'd become very sloppy. With reverb, you can release a note early and the guitar still sounds "wet." However, without reverb I really had to relearn how to sustain a note to keep the guitar from sounding too dry. So, I agree with Derek...3D amp + resonant guitar + proper technique = no need for reverb. The exception is when sitting at home playing to backing tracks. They're typically very wet so I like to use a delay pedal to help the guitar sit in the mix. A good friend of mine once told me that reverb and delay should never be used as effects, only as tools to adjust the sound stage.

As to the loop questions, I've always felt a loop should be buffered, inserted right before the PI, and be gain neutral.

Exactly!!!