Delay Pedal Before vs. After Volume Pedal in Combo Rig

Steve Feldman · Post by **Steve Feldman** » 18 Feb 2002 5:41 pm

I noticed something today that never occurred to me before and I can't explain what's going on.

I typically run a Boss DD-3 for a little delay between my vol. pedal and a Fender Vibrasonic. But today, I hooked it up before the vol. pedal (i.e., PSG > DD-3 > Vol. Pedal > amp) and there was a dramatic increase in brightness and clarity in the highs. Cool! So then I kicked on the DD-3 and everything was hunky dory except I noticed that at higher volumes, there was a very slight distortion occurring. I next hooked up a Matchbox right out of the PSG and tried tweaking that to no effect.

Anyway, I put the DD-3 back after the vol pedal like it was before, and everything's back to 'normal'. Funny thing is this: I then pulled the DD-3 completely out of the mix and was expecting to have the highs come back, but there was no effect whatsoever on the tone.

So, the question is this: If the DD-3 after the vol. pedal has no effect on the tone (as compared to the case when it's not even in the mix), then why does the signal get 'brighter' when I put it before the vol. pedal? Also, why is it distorting when I put it before the vol. pedal, and is there a way to keep this improved signal without the breakup?

Don't tell me, I know: Buy a Hilton pedal, right?

Thanks for any thoughts - I'm stumped.[This message was edited by Steve Feldman on 18 February 2002 at 05:42 PM.]

Donny Hinson · Post by **Donny Hinson** » 18 Feb 2002 6:47 pm

There's no voodoo involved!

When you put the effect between the guitar and the pedal (which is where it should be!) you're both building the signal that goes to the pedal, and isolating the guitar's pickup from the pedal. Some pickups are more sensitive to changes in loading than others, and these pickups will sometimes benefit from the little "boost" that your DD3 is providing. How much cable are you using (in feet) between the steel and the amp? I recommend no more than 15' total, and less is better (for the sake of highs, anyway). Since the distortion is taking place when the volume pedal is at max, it's safe to assume the distortion you're experiencing is due to overloading one of the amps first stages. If you have an input volume and a master on the amp, lower the input volume a little, and crank up the master. If that doesn't correct the problem, then the overloading is taking place at the input of the first stage (before the volume control) and the only way to avoid it is to use less pedal, or attenuate the signal a little with another volume control in the line---but then, you'll be right back where you started!

Essentially, as you described, your "new setup" is doing exactly what a powered volume pedal does, and that is to boost the signal, and provide isolation. I do not use a powered pedal, but I have no trouble with highs. On the contrary, I seem to always have more highs than I need, but as I said, different pickup/amp/effect/cord combinations behave differently.

Use what works for you.

Steve Feldman · Post by **Steve Feldman** » 18 Feb 2002 9:10 pm

Very interesting. I buy it! The cabling is very short (and GeoL), so I don't think that's it. Also, I only have a single volume (no gain) control, so I have no possibility there.

So, if it's overloading at 'the input of the 1st stage (before the volume control)' as you say, can I slap a slightly lower gain tube (or tubes, acutally) in there to help? I assume you mean in the preamp section. 'Course, I already have GE 5751 tubes in the first 3 positions, and these are already lower-gain 12ax7-type preamp tubes. The power amp section has the original (4) Fender Sovtek 5881 tubes in there. Anything I can do tube-wise to help?

Also, I was joking around about the Hilton pedal, but would this help at all in this situation, or would I likely just have this same effect across all of the pedal travel? And the PU in questionis L710 (hard to figure how that thing would benefit from a boosted signal - the thing seems so darned efficient already!).

Finally, I really do have plenty of highs any way I go with this amp, but there was a noticable difference with the new setup - and I don't want to give anything back!

Thanks for the info, Donny. Sounds like you're right on target.

[This message was edited by Steve Feldman on 18 February 2002 at 09:19 PM.]

Jeff A. Smith · Post by **Jeff A. Smith** » 19 Feb 2002 1:38 pm

Just an uneducated guess on the distortion, if it isn't of the nature that Donny is considering; Sometimes the repeat signals from my delay pedal have a slightly distorted quality, and it seems feasible that if these shaky signals were then fed through a volume pedal this quality might increase. This is just speculation, though. This obviously wouldn't apply if the distortion is still present when the delay is turned off.

Peter · Post by **Peter** » 24 Feb 2002 6:33 am

Regarding the distortion...
Try adjusting the pickup by increasing the distance between the strings and the pickup?
Worth a try...if it doesnt work, you just put it back where it was.

Kevin Post · Post by **Kevin Post** » 6 Mar 2002 8:03 am

Here's an alternative view

The volume pedal is eating the tone. The digital delay converters change the pure pickup sound from analog to digital, and back, but at a lower impedence. The volume pedal likes the lower impedence...hence, more highs.
The distortion is a mystery, not enuff info.

Buck Dilly · Post by **Buck Dilly** » 15 Mar 2002 5:25 am

I also have a floor delay and a Vibrosonic. Try this- Steel into Volped into Reverb channel. Then take signal from channel Input #2 into delay, delay out into channel one. This allows for tonal tweaking of "delay only" sound. This reduces percieved noise from the delay, and permits a less altered signal from the instrument to the amp. And you can get a nice tape echo sound by tweaking the tones a bit. THis is an excellent trick for guitarists who have an extra volped. Place the volped before the echo and crank the echo on the fly.

Steve Feldman · Post by **Steve Feldman** » 15 Mar 2002 6:48 pm

Buck - I have a '90s VibrAsonic and this thing does not have an input for 'Reverb channel' that you describe. Just the 2 ins from the steel channel and the 2 ins from the guitar channel.

And Bill, I'm not sure it's the PU, but thanks for the tips anyway, guys.[This message was edited by Steve Feldman on 15 March 2002 at 06:48 PM.]

Buddy Emmons · Post by **Buddy Emmons** » 16 Mar 2002 8:39 am

What you need to consider is that the steel output is two to three time the output of the pickups these stomp boxes are designed for. I've had this problem running toys directly off the pickup for years. When you push the output of a steel pickup into the input of the stomp box and close your volume pot slightly, you are in affect creating a bottleneck in the output signal and forcing an input overload in the stomp box.

You have the same problem with a rack-mount processor when you lower the output once you've set the maximum input level. The recommended way to set the input level is to shut off the output and play and boost the input signal until you see a red light. Then back it off slightly and open the output to the desired playing level. The same overload situation applies when playing through a mixer when you have the faders up and the master gain down. The bottleneck factor and wanting the delays to fade naturally are the reasons I prefer using delays and most other effects behind the volume pedal.
[This message was edited by Buddy Emmons on 17 March 2002 at 08:07 AM.]

Buddy Emmons · Post by **Buddy Emmons** » 16 Mar 2002 8:45 am

Reload for edit.

Ken Fox · Post by **Ken Fox** » 16 Mar 2002 10:29 am

I believe what Buddy is referring to is sometimes called "signal to noise ratio" and "headroom settings". I totally agree with his procedure and have used it for years to set up PA and guitar processors.
One thing I have noticed is that trying to run a volume pedal after the output of a Profex or other preamp processor is a disaster! It seem it always distorts. I assumed that the pre-amped signal is too much for the volume pot of the pedal to handle?? The only reason I ever tried this was to get a full signal into the Profex, as a varying signal seemed to not work well with the built in compressor of the Profex. I now use a Hilton Sustainer before my pedal and no compressor on the Profex. Seems to work very well, and the guitar sounds so much nicer! Now if I could just learn how to play that thing!!!

Steve Feldman · Post by **Steve Feldman** » 16 Mar 2002 10:54 am

Interesting thoughts, guys. I think I'll try running the same guitar through my rack system with the effects in some different positions (with a fixed I/O setting [and high input level]). I have a Lexicon MPX-1, btw, Buddy, and I love this thing. Seems to give a lot of folks heartburn though (someone who also has one actually e-mailed me once asking for help in setting up "Lurch"...).

I keep it simple - using it mostly just for reverb and delays - but it sure would be cool to hear about some of your thoughts on the settings you find useful. Just echoing (oops...bad pun...) the topic brought up on the BE Q&A. WHOA! Just saw the other post...now I have something to do this weekend!

Thanks once again for the thoughts everyone. [This message was edited by Steve Feldman on 16 March 2002 at 10:57 AM.]

Buddy Emmons · Post by **Buddy Emmons** » 16 Mar 2002 11:09 am

Steve,
The moral of the last post you saw is that loosening the screws didn't necessarily improve what already existed; it merely restored what was lost by tightening them. Don't want your ax to fall apart in the middle of the set.

Ken Fox · Post by **Ken Fox** » 16 Mar 2002 11:12 am

The more I thought about this, the more I think I realize what is happening here. The output of an active electronic device (pedal of proccessor) wants to send it's amplified signal to the input of another device. For optimum transfer of voltage, the input impedance needs to be ten times (bridged) the output impedance. When the volume pedal approached full on it represents a 500,000 ohm load to the output signal, hence most of the signal arrives at the input of the amp (which has a input impedance graeter than tens times the output impedance of the source). As the pedal approaces "off" it is a near zero ohm (dead short) to ground. The output signal is dropped across the internal impedance of the device generating the signal. Active devices do not like a dead short, hence the distortion factor! A pickup does not tend to distort as bad as the impedance approaches zero. I think I am on the right track here. Maybe Jack Stoner or Keith Hilton (two guys with a whole lot more electronics than I have!) might chime in here. I would like to get some input on this one from them as well.[This message was edited by Ken Fox on 16 March 2002 at 11:13 AM.]

ajm · Post by **ajm** » 16 Mar 2002 5:38 pm

I'll try to state what I think is happening. I may have missed it, but I'm assuming that you're using a passive volume pedal.

Guitar-delay-volume pedal-amp:
The active electronics in the delay are acting as a buffer, which is good (for most people, anyway). The pickup is not being loaded down by a lower impedance, and in addition is also now being loaded by a constant non-varying impedance. This is why you've got plenty of highs. For a similar experiment, try using just a volume pedal with a 500K pot, and then go to one with a 250K pot. I'm betting that you'll like the 500K better. I've posted on this several times before; I sometimes use a Boss compressor between the guitar and volume pedal. You don't need to have the effect on to get the benefit of the buffer circuitry inside the pedal.

The bad news is as BE said. The steel pickups are awfully powerful, and what I suspect is happening is that the guitar is overloading the delay with too much juice. I really doubt if you are overloading the input to your amplifier. Keep in mind that in this scenario the delay is essentially running the same as if you put it after the volume pedal and kept the pedal full throttle all of the time. It's always getting the full signal of the pickup. You might try going matchbox-delay-volume-amp. Adjust the level of the Matchbox until there is no distortion like BE said. If you are noticing the distortion only when the delay is kicked in, I suspect that you are hearing digital distortion caused by overloading the processing portion of the delay pedal. (I don't know what the innards of the delay pedal are really like, but I suspect that there is an analog circuit and a digital one in parallel.) Try this: hook it up with guitar-delay-volume, turn the delay on, but set the mix on the delay (if there is one) so that it is all dry signal with no delay mixed in. If the distortion is not there, then this could very well be where it's coming from.

Guitar-volume-delay-amp: The passive pot-only volume pedal is loading down the pickup and taking some of the highs away. It's also lowering the output even when it's all the way down just enough so that it's not overloading the delay. Also, keep in mind that in this set up, usually when the volume pedal is all the way to the floor that this is when the signal is decaying, so it's not a full strength signal. Try this: push the volume pedal all of the way down and play. If there is distortion now, I'm not too surprised.

I think if you go guitar-matchbox-delay-volume-amp and mess with the matchbox level a little you may get the combination you want.

I hope some of this helps.

Steve Feldman · Post by **Steve Feldman** » 17 Mar 2002 6:50 am

AJM - What you said makes sense. I tried a couple of things last night:

1) With guitar > delay > volume pedal I can get the distortion down (or off) with a dry signal on the delay (Doh!).

2) Putting the matchbox in front (guitar > matchbox > delay > VP) and tweaking the levels had no effect on reducing distortion from the delay pedal.

I'm back to putting the delay after the VP, but I wonder if going with one of these new active volume pedals and placing the delay after the VP wouldn't help?

Anyway, it all sounds damn good however I have it set up. It's just tough to give up those crisp highs once you get used to 'em.

John Lacey · Post by **John Lacey** » 18 Mar 2002 8:18 am

"The bottleneck factor and wanting the delays to fade naturally are the reasons I prefer using delays and most other effects behind the volume pedal." Buddy, I thought in previous posts about effects that you liked to run your effects after the vol. pedal?

Buddy Emmons · Post by **Buddy Emmons** » 18 Mar 2002 9:06 am

It was a poor choice of words John. I was thinking after and came up with behind.

jim milewski · Post by **jim milewski** » 21 Mar 2002 3:28 pm

how about the unnatural sound of backing off the volume pedal with reverb or echo in the mix and having it end suddendly