In this post I will discuss some of the whys and wonders of the non-buffered effects loop. If any of you want to chime in with more in the way of technical details, etc., please feel free to add comments; it will be helpful for those who need to hear more about dB’s and volts.

For the most part, I will keep this post in layman’s terms, which is best for me too, because when I start trying to wrap my brain around some of this stuff, I get a headache! I just wanna play my guitar!

So here is the scenario: You finally get your D-style (or otherwise) amp and you might have opted out of the reverb option or the buffered effects loop (pedal level) due to the additional expense.

However, when you plug your pedals into the non-buffered loop, the amp sounds anemic, low in volume and your dreams of a sprinkling of cool effects on your expensive investment, seem to fall short of tonal heaven.

Then someone comes and tells you about a device called a Dumble-ator, or clone thereof, such as a Loop-a-lator by Bludotone, or the Kleinu-lator by Ceriatone, or the ELI 1/2 by Two Rock.

Well, these units will surely remedy the problem. But that means another piece of gear that you have to carry around to your gigs, more power chords to plug into AC, more 1/4-inch plugs to plug in (twice!) to the amp, and then a few more knobs to tweak. Please, no more knobs! Arghhh!

Then someone else tells you they just use pedals through the front of the amp that will work great: What? Why? Which?

First off, most of these high-end Dumble amps and clones come standard with a passive, +4 signal-level effects loop.

In layman’s terms (based on information that my engineer copied and emailed to me after my begging for simplicity on the subject!)  +4 is the “pro” signal level—the level that high quality units expect to see, otherwise referred to as “line level.” Cable connectors for this type of signal are usually XLR (like mic cables) or TRS—which are like guitar cables except they have Tip/Ring/Sleeve balanced connection (an extra stripe on the plug) as opposed to instrument cables, which are usually just Tip-Sleeve and unbalanced.

The alternative to +4 level is -10, which is the consumer or semi-pro standard. These connections are almost always unbalanced, and you need to maintain shorter cable lengths to avoid hum, buzz, radio interference, and signal degradation—  compared to good balanced line level cables (+4) can be run for a couple of hundred feet. The connectors on -10 equipment are either 1/4-inch guitar/instrument cables, or RCA plugs and jacks (like you see on a home stereo). Note that on many of these D-clones, the effects loop, even though it is +4 line level, will often have simple 1/4-inch guitar jacks for ins and outs. This is still compatible with the effect unit, even the the effect unit might have the TRS (ring-tip-sleeve). Both have 1/4-inch guitar jack connections.

So in a nutshell, if you use a guitar level pedal (unbalanced) with your D-Style effects loop, there is a mismatch in signal level, hence the anemic tone that you might experience. What is the solution? Well, there is the Dumble-ator, or clone thereof, of which we spoke earlier. This device, about the size of a single space rack unit or smaller, is the missing link that will correct this signal level disparity and restore your full tone. Depending on the model, it might also allow you to add in the appropriate and matched level of effect in parallel.

These loop devices essentially allow you to match the signal of the output and input of your amplifier effects loop with the signal of the effect device that you are using, whether balanced or unbalanced, +4 or -10. Of course, if the effects unit that you are using has the line level option, then you probably do not need them! (Unless you like the extra work of plugging stuff in and having and more knobs to tweak!)

An amp that comes with a buffered effects loop, essentially has a built-in Dumble-ator or maybe it is the other way around: a Dumble-ator is essentially the workings of an amp that make the loop “buffered,” except it exists outside of the amp. Hmmmm, well I guess the reasons for this unit being separate might be:

  1. amp is cheaper and possibly quicker to make (some of these boutique babies have a waiting list of two-to-three years!
  2. less “stuff in the amp,” so it can be smaller and lighter, and in simple terms, less complicated, technically, maybe even a little quieter.
  3. If you are going to be using high-quality studio grade +4 effects, a buffered loop, it is really not needed.
  4. Certain effects (other than delay and reverb) can simply go through the front of the amp, especially if your amp does not have an OD switchable channel

Most floor guitar effect pedals run inputs and outputs at the unbalanced level. And today most effects loops on non-boutique/mainstream amps are buffered. However, increasingly, we are finding manufacturers catering to the avid, growing population of folks owning high-end boutique amps that come ready with a +4 loop, ready for studio high-quality studio-grade effects.

TC Electronics seems to be on the wave of this trend with products such as their Nova System and Nova Repeater pedals. (Click on the images below to enlarge.)


Some other boutique manufacturers such as Fuchs also create some options for +4 effect loopers. Andy Fuchs makes a very interesting pedal called a Verbrator which has High Quality Tube Reverb along with what amounts to a built-in tube (Dumble-ator) effects loop. This comes in a relatively small pedal-sized packaged.

There are many rack units that offer this option, and few floor pedals that do. If there are any of you who are hip to any other high-quality floor pedal manufacturers that are offering the line-level option, please list in the comments section of this post. I like small, light, and not too many knobs!!

Now some of you might be just thinking, ‘Well, why not just plug in through the front of the amp?’ or  ‘Why not use whatever effects you have after the guitar before the amp?’

Well, the answer to that is: Hmmm, why not?

Well, I guess the most appropriate place for certain types of effects is after the preamp and tone-stack and before the power amp (through the effects loop). If your amp has an OD channel, as do most D-Style amps, and you plug your delay through the front of the amp, when you hit your OD footswitch, you will be OD-ing your delay sound. Well, that can be an interesting effect, but most agree that delay will sound better AFTER the signal has been overdriven. Effects such as delay and reverb sound best through the loop.

If your amp does not have an OD channel, the placement of effects in the chain, might be a little less crucial, since you are probably either turning up and cranking the amp or maybe using an overdrive pedal or boost to get your “up to 11” sound.

I will say that I think a high-quality effect unit, whether reverb, delay, or otherwise (or some combination of these) sounds HEAVENLY through a +4 effects loop. Essentially, there is no added noise and your amp will take on a 3-D quality.

Depending on your setup and pedal choices, it might makes sense to get a buffered effects loop at the time of purchase of your D-Style amp. It will probably add expense and a little weight to your rig.

Many manufacturers of these D-Clone babies don’t offer the buffered loop as an option. My personal optimal preference might be to just use this +4 effects loop with an effect that is high-quality line level. Seems that way, you carry the least amount of stuff to the gig. (Especially considering more pedal manufacturers are making this line level an option on their pedals, sometimes with just a flick of a switch.)

Please share your thoughts and experiences with this. Happy Looping!