Headroom on distortion pedals?

[picker]

In some of the posts of late, the subject of running pedals capable of it at 18v has come up. The advantage of that seems to be increased headroom. This seems to be the case on overdrive/distortion boxes, such as the Xotic SL drive, The Fulltone OCD drive and some Wampler pedals.

 

That confuses my rapidly aging brain. Isn't the point of using distortion pedals to cause signal clipping, which is a result of exceeding available headroom? I can see the desirability of increased headroom in a compressor, like the Xotic SP, etc. But wouldn't that defeat the purpose of a dirt box?

 

Can somebody help out a befuddled old fart, and explain this for me?

[KuruPrionz]

I've thought the same thing, that the word "headroom" was maybe not quite accurate.

 

They could mean that they've got more range of "not that dirty to kinda dirty to clipping hard", which does make sense and is something I really love about some of my amps. (all solid state - no tubes).

 

Some pedals are going to go straight into filtered square waves no matter what you do. Others have more range and maybe going to 18 volts increases that range, which could be called headroom I guess.

[CEB]

Sometimes there is clipping and there is nasty sag that farts out. Especially if you use hot pickup or want a dirt box for pedal steel.

[Caevan O’Shite]

It varies with the particular pedal, but running drive pedals on 15v or 18v (I've seen at least one made for 30v!) can give you a greater dynamic range for playing from softer to harder and having the pedal respond accordingly, with less squashy compression. Sometimes this also reduces 'sag', as CEB points out. Sometimes the pedal may seem more lively and present.

 

It can be a little like the differences between lower and higher watt versions of the otherwise same amp, with lighter-duty or beefier power-supplies, transformers, etc.

 

Sometimes, some players might prefer said pedals to be run on 9v, anyway, or even less. They might want a more compressed tone and feel; some dirt pedals maybe even sound a little darker at 9v or lower. Maybe even deliberately going for 'sag'.

 

Some pedals may not seem much different either way; and the guitar, pickups, other pedals- the player- all also come into play.

 

 

I have that Xotic SL drive Overdrive/Distortion, and I bought it to have a Marshall-toned OD/Dist pedal that wouldn't get flubby, blubbery, muddy and overly throbby with my Uni-Vibe in front of its input. The SL Drive succeeds very well for that, and even better when run on 18v (which it was designed to handle, as an added tone and feel option). It just opens up and sounds clearer and livelier on 18v; it's not a huge difference, but it is a noticeable and appreciable difference. The player WILL notice, an audience member might.

 

 

I also have a pedal based on the "triangle era" EH Big Muff Pi pedals, a VFE Fiery Red Horse (V1), that can be run on up to 15v, and also has its own built-in Power control to lower voltages to three parts of its circuits- and let me tell you, run on 15v with Power and Sustain maxed, it is MEAN! That way, it approximates the later "V4"/V5" "IC/"Op-Amp" Big Muff Pi stompboxes, that Billy Corgan of Smashing Pumpkins is so fond of- and I know what I'm talking about, a 1979 V4/V5 BMP was my second fuzztortion pedal way back when. (It was stolen years ago, before Smashing Pumpkins, when nobody thought it was special and everybody wanted the transistor BMP's- but I loved it and couldn't get the same out of the "regular" BMP's!)

 

If I run that same VFE FRH pedal on 9v, maybe roll the Power back just a smidge, dial the Sustain somewhere considerably less than maxed, it's then in David Gilmour/Pink Floyd land. That's great! But not what I want that pedal for... I want mean turbo buzztortion from it! Yeah! So 15v it is!