Sometimes you need a Boost
And possibly too much treble.
This could be the slogan for the Dallas Rangemaster Treble Booster or a wide range of stimulants. Just look at the notes on this thing—they’re literally off the charts. But that was the 60s, and no one had ever heard a Boss Metal Zone into a Peavey 5150. By modern standards, it is, perhaps, a bit more mild.
I have a friend who also makes pedals and I mentioned to him that I was making this. His [slightly sanitized] reaction was, “Screw Rangemasters, they don’t even sound good.” I’ve never heard one in person, and everything is subjective, but he also likes a lot of bands with names like Among the Abhorred, or Futile Triumph, or Fatal Ångst, or Dour Syzygy, or Sepülchre Œuvre, or Me Want Cooookie, or Quetzalcoatl’s Cloaca, or I’ve Already Abandoned Hope All Me Who (Whom?) Entered Here. I think in a lot of that stuff, the 9th string on the guitar is tuned 5 octaves below middle C and the bass guitar can only be heard by whales, at which point, one more transistor and a filter cap isn’t going to excite anyone. The Rangemaster came from a time when a little Eric Clapton was hobbling on one crutch into a guitar shop on Denmark Street, whimpering, “Please sir, I’m keen on this music I’ve ‘eard, but me guitar goes all flub-a-dub when I do the hoobly-joobly,” at which point the Rangermaster was just the analgesic that was needed to get through that exchange.
Does it even sound good? I don’t know. It’s no Wyld Stallyn, but it certainly does a thing. I mostly liked that I could build it entirely with parts that I had on hand, and it gave me a reason to make a pedal utilizing the color scheme of my mom’s Tupperware.
The Mild Stallion is not an accurate representation of the Dallas Rangemaster circuit, but is a treble booster in a similar vein. The original Rangemasters used germanium PNP transistors, and this does not. Germanium transistors have some absurd problems, like being electrically inconsistent and temperature sensitive. They’re also increasingly rare, since they haven’t been used in non-guitar electronics in decades, and can be expensive due to both their scarcity and the fact that you wind up paying reputable sellers for their time in sourcing them and sorting out the ones that are garbage. Despite this (or because of this) they are considered highly magical by pedal people on a tone quest, but it’s not a well that I can bring myself to fall down. The “PNP” part refers to the nature of their internal bits (positive-negative-positive), and PNP transistors can be more difficult to use in pedals that are meant to be powered the “normal” way that modern pedals are powered, (which is, of course, backwards from the way everything else is powered). The Mild Stallion uses a more common, though still outdated, silicon NPN transistor: a 2N3904.
The circuit used in Mild Stallion is once again one of dylan159’s, the same person who designed the circuit for the Extra Medium. It’s his Troupple Booster, which is an original design released under a Creative Commons BY-NC-SA license.
The one modification that I made was to add a switch to change the input capacitance, and therefore the amount of low frequency content that gets rolled off before the signal gets amplified (which is how it boosts treble). I tested a bunch of values when I breadboarded it, and wound up using a 4.7nF capacitor, which is the suggested value and creates a high-pass filter similar to a Rangemaster’s, plus a 100nF capacitor as the second setting, which amounts to a tiny amount of low cut, but a grittier boost. The cutoff frequency of a high-pass filter (which isn’t a hard cutoff in a first order high-pass) can be calculated with 1/2πRC, but “R” was difficult for me to figure out because in this case, it’s the input impedance of the circuit. I did too much math, a β got in there somehow, and I think the stock cutoff frequency is around 2KHz. When the 100nF cap is engaged, it’s more like 100Hz, which is barely overlapping with the fundamental frequency range of a guitar but a lot more rumbling junk gets through to the transistor. dylan159 specifically recommended that I not try to make it full range with the second setting, and I may yet dial it back, but I’m trying it for now.
I don’t think it sounds bad. I originally imagined that its main use would be pushing the front end of a mostly clean amp into breakup, and it will do that, but it may be more interesting for its ability to add articulation to a heavier guitar sound. I like the way it makes a guitar feel when going into another distortion pedal or a cranking amp, and in a mix with drums and bass, I don’t miss the low end. The following sound sample has several tracks:
- Main guitar: Emomaster > Mild Stallion > mostly clean Deluxe Reverb with light “vibrato” engaged
- Other guitar: Coronacaster > Mild Stallion > George Washington Slept Here > Deluxe Reverb
- Bass: Who puts a treble booster on bass? Probably no one, but here we are. P-Bass > Mild Stallion in “fuller range” mode > DI