Foot Volume Notes

Pedal to the Metal

I've been playing a lot with the foot volume lately. It's implemented very well. There's really only one thing I would change and it's really more of an enhancement than a fix: Instead of supporting two expression pedals to control volume at different points in the signal flow, I wish one of the expression pedals could be assigned to control various other parameters in the effects like, say, delay level. That would be far more useful.

It does work as advertised however. Here are some of the finer points I've discovered.

Which Expression Pedal?

If you don't have an expression pedal, the first question is going to be what pedal should you get? Boss lists its EV-5, EV-30, FV-500H, and FV-500L pedals as compatible and it recommends you only use one of these pedals, cryptically warning that it might damage something if you don't.

I've never heard of an expression pedal damaging anything unless it wasn't actually plugged into an expression pedal jack. So I'm a little skeptical of that warning. But there is definitely a legitimate reason to use one of their expression pedals. Different manufacturers use different value potentiometers in their expression pedals and a device like the Tube Amp Expander may expect to see a particular value of pot for the expression pedal to function correctly. So if you don't already have an expression pedal, the easiest thing to do is just buy a Roland/Boss. Here's my take on those pedals:
  • EV-5 – This is the most basic and least expensive expression pedal that Boss makes. It works fine and provides a minimum volume control, which is handy with the TAE as well as other devices you might connect the pedal to. The downside of this pedal is that it's plastic and its cable is not detachable (which makes it harder to replace if it shorts out), but if you treat it well it should be fine.
  • EV-30 – This pedal is a step up with an aluminum housing and dual expression pedal outputs. It also has a minimum volume control. The aluminum is nice, but you won't have any use for the dual expression pedal outputs with the TAE even though it support two pedal inputs. The reason is because both the outputs on the EV-30 are simultaneously controlled by the single treadle, which means that sweeping the pedal always affects both outputs. Why would you want to sweep both of the TAE foot volume controls at once?
  • FV-500H – This is another step up. The housing is built like a tank and has a really nice, adjustable treadle action. Mechanically, it's a top-notch pedal – comparable to an Ernie Ball volume pedal which I consider the gold standard for treadle pedals. The FV-500H can function as a guitar volume pedal placed inline between your guitar and amp or it can be used as an expression pedal. You could also do both at the same time, but I don't know why you would. It has a minimum volume control as well as a tuner output (which won't work unless you're using the pedal as an inline volume pedal). The "H" in the name is for high impedance, which means that it works fine with a guitar plugged straight into it when used as an inline volume pedal.
  • FV-500L – This is the one I have. I bought it as a volume and expression pedal for my keyboard rig many years ago. It works great as an expression pedal with the TAE. It's almost identical to the FV-500H, except that it is low impedance and it supports stereo signals when used as an inline volume pedal. This pedal is designed to work with keyboards, but if you have a buffered bypass pedal of some type (such as any Boss or Ibanez pedal) you can also use it as an inline volume pedal with guitar. Just put the effect pedal before the FV-500L in your signal chain. You don't even have to turn the effect pedal on because it will always output the low impedance signal that the FV-500L wants to see.


Out of the box, my TAE's default volume pedal settings had the Volume Max and Volume Min parameters set to 0. So the first time I plugged in the volume pedal, all the sound disappeared! And that led to a moment of panic that something was broken before I thought, "Hey, you know there could be something with the internal settings that is causing this..."

Each expression pedal input on the GA-FC foot controller (Pre-Effect and Main) has it's own configuration parameters, accessed in the the "System Settings" section of the Editor. When no pedal is plugged into the jack, the settings for that expression pedal input will simply be ignored.

Because they're System settings, they apply globally to all Rigs. So you can't change the behavior of the pedals with each Rig. Now that I think about it, making the pedal settings Rig-specific will be essential if they ever update the TAE so that the pedals can control more than volume.

If you want just a straightforward volume control, set Volume Min to 0 and Volume Max to 100. That will give you the standard behavior of heel-down is silent and toe-down is full blast. You can get a reverse volume pedal (volume goes down as you rock the pedal forward) by setting Min to 100 and Max to 0.

Let's say that you want to use the pedal to fade between a lower volume rhythm sound and a max volume lead sound. In that situation you'd want the amp to still have some volume when the pedal is in heel-down position.  If your expression pedal has a "minimum volume" knob (and all the Boss ones do), you should use that to set the volume in heel-down position because you can readjust it at any time without having to fire up the Editor. But if your expression pedal does not have that feature, then you can do it by setting the Volume Min parameter to something greater than 0. You'll need to experiment to find the value that works best for you. 

Off the top of my head, I can't think of a good reason to set the Volume Max parameter to anything but 100 except for configuring a reverse volume pedal as I described above. Setting Volume Max to less than 100 is analogous to putting a speed limiter in a car – the vehicle is capable of more but it's been artificially capped. And you can't remove or change the cap without using the Editor app, which would be a big hassle at a gig. If you can think of a good reason to limit Max Volume like that, please leave a comment!

The Volume Curve parameter sets the response curve of the pedal – how quickly or slowly the volume ramps up as you sweep the pedal. This is totally a personal preference thing. I like to use a pedal for volume swells and creating a slow attack envelope on notes and chords. For that, I like to have most of the volume ramp-up at the front end of the pedal sweep. So I use the Fast setting. If I used the pedal only to set volume for different sections of songs, I might prefer the Normal setting. Play with all of them and figure out what works best for you.

Main or Pre-Effect?

As I've said a couple of times, the TAE supports two expression pedals. One called "Main" which controls the volume at the end of the signal path just before the speaker and line outputs, and another called "Pre-Effect" which controls volume between the FX loop and built-in effects. I imagine a common question is which one should you use if you only have one expression pedal? Here's my take:
  • Main – Use this input when you want a volume that is effectively a variable mute switch. When you roll the volume down, it's going to silence everything instantly.
  • Pre-Effect – Pre-Effect volume will preserve reverb and delay tails to sustain your sound a bit after you've rolled back the volume. Use this input if you're going to do volume swells. Personally, I strongly prefer this way of controlling volume because I think it's way more expressive and it will still mute things quickly enough if I need it to.
One of the things I do a lot in my playing is roll back my guitar's volume to clean up my overdrive sound. I've done this a lot with inline volume pedals too. Unfortunately, it's not possible with the TAE foot volume feature. A volume control must be placed before the distortion-generating device to affect its gain. It's a drag that the TAE can't do it, but you can always use your guitar's volume control or a volume pedal placed inline before your amp or overdrive pedal if you absolutely need that capability.