Anyone tried putting a preamp/boost in front of a drive circuit in a pedal?

[airvian]

So I thought about what I could build next and I wondered about putting a boost/preamp circuit in front of another OD circuit in a pedal, so I have a preamp and a master gain control of sorts. I was thinking about putting something like an EP3 preamp stage in front of a Tonebender Mk3 or something like a Fairfield Barbershop and keeping it all in one pedal with only one footswitch. Has anyone tried anything like it before?

[idy]

The old fashioned fuzzes "like" to be directly connected to guitar, so a booster before changes character/frequency response. But the fuzzfactory is just a fuzz face with added knobs fed by a  booster.

So booster into TB is maybe losing something you might want, but booster into Barbershop is how a lot of people use them.

booster into overdrive can push it closer to fuzz. Booster into fuzz=mayhem, maybe you want that...

Lots of us stack a clean booster before a drive pedal. Some leave the booster on all the time. Could put them in one box. Lots of examples: BYOC OD2, King of Tone (two ODs, people might set up one as a clean boost)... Some people want booster after drive.... Morning Glory...

[GibsonGM]

Yup, what he said.  If you have a transistor amp (like my little Marshall practice/recording amp, uses a 4558 opamp preamp drive circuit), you can juice it with a boost and get some good results.. Push too far and it just sounds like ugly fuzz tho.   Same for pedals - even keeping a distortion on 'half gain' and then hitting it with a boost is usually a totally different tone.

Play around, use discrete circuits....boost into whatever OD or disto pedal, see what you come up with. Then you could put them in 1 larger box, and have a 2nd footswitch for the boost on/off, too.  Some people come up with some pretty eccentric switching arrangements, putting the boost before or after the dist or what have you. 

[Mark Hammer]

I've built a few two-in-one pedals.  One of the features I include that is VERY handy is an order-flipper switch.  This gives the option of putting the boost into the drive OR the drive into the boost.  Having it be a toggle means no additional patching is needed.  Boost into drive increases the intensity of the drive, without necessarily increasing the volume much.  Most helpful for having a basic slightly dirty tone, and then kicking the dirt up a notch by boosting the input to the drive.  Drive into boost is for hiking up the volume level noticeably, for a solo, or to push the amp into saturation.

Two-in-one pedals are gaining in appreciation, and I've even seen a few include order-flipping.  Order-flipping can be done with a 3PDT toggle.  Some diagrams show a 4PDT switch for order-flipping, but I find the position of the bat handle on the toggle provides all the visual indication you need, so there's no need for the extra poles to switch LEDs.

[soggybag]

I like the boost after the dirt, especially if it's a boost you can overdrive, like Super Hard On, MOSFET boost, or Mini Booster.

[amptramp]

The input from the guitar is signal plus partials, signals that are almost harmonic but are slightly off integer multiples of frequency due to different amounts of damping and power delivery at each frequency.  The extra harmonics that come out of a boost are all lockstepped to the fundamental and are exact integer multiples.  The combination of partials and harmonics may cause some intermodulation which is the sum and difference frequencies so using a low-impedance input on a fuzz reduces the upper partials because the inductance of the pickup forms a voltage divider with the input impedance that gives reduced output at higher frequencies.

A boost stage preserves the higher partials and feeds them to the fuzz circuit, so the partials and the harmonics emerge from the fuzz if the booster is first.  If the booster is last, it just amplifies the signal the fuzz produces by itself.  The effect is completely different.  If you have linear stages, the order doesn't matter but if you have a non-linear stage like a fuzz in the mix, changing the order changes everything.

[Ben N]

booster into overdrive can push it closer to fuzz. Booster into fuzz=mayhem, maybe you want that...

Lots of us stack a clean booster before a drive pedal. Some leave the booster on all the time. Could put them in one box. Lots of examples: BYOC OD2, King of Tone (two ODs, people might set up one as a clean boost)... Some people want booster after drive.... Morning Glory...

I find that a flat response boost tends to push the OD towards fuzz, but boosts centered on a specific frequency work well pre-OD as a lead thing. I have used a clone of a Catalinbread Varioboost for this, and currently have a Pearl OD-05 clone with the drive set low serving that function. Works for mids & treble boost, depending on the sound you want and the OD being overdriven.

[marcelomd]

Clean boost -> Overdrive = More gain/drive/crunch
Overdrive -> Clean boost = More volume
Dirty boost -> Overdrive = Same as stacking overdrives. Which I find more interesting.

There are lots of dual pedals (2x overdrive, or boost+overdrive) out there, with and without order switches, like Mark said.

The Tech21 Character pedals have a mid control (boost and cut) before the main clipping stage, which changes the... character... of the distortion.

Wampler's Plexi Drive Mini has a switch that engages "a kind of tube screamer" in front of the main circuit.

[Mark Hammer]

The input from the guitar is signal plus partials, signals that are almost harmonic but are slightly off integer multiples of frequency due to different amounts of damping and power delivery at each frequency.  The extra harmonics that come out of a boost are all lockstepped to the fundamental and are exact integer multiples.  The combination of partials and harmonics may cause some intermodulation which is the sum and difference frequencies so using a low-impedance input on a fuzz reduces the upper partials because the inductance of the pickup forms a voltage divider with the input impedance that gives reduced output at higher frequencies.

A boost stage preserves the higher partials and feeds them to the fuzz circuit, so the partials and the harmonics emerge from the fuzz if the booster is first.  If the booster is last, it just amplifies the signal the fuzz produces by itself.  The effect is completely different.  If you have linear stages, the order doesn't matter but if you have a non-linear stage like a fuzz in the mix, changing the order changes everything.

Which is why most contemporary "clean boosters" will include some form of variable treble cut, to suit the purpose.

[airvian]

Thanks for all the replies and ideas. I use a solid-state practice amp at home (an old Vox pathfinder 10) and have lately just run different "preamp style circuits" pedals like the broadcast, benson, peavy decade preamp or IVP tube voice OD section into it as an always on kind of thing and then stack it with whatever I feel like. I usually run a bc183 fuzzface first in the chain and add in whatever fuzz/OD/octave circuit I have on the shelf after it but before the preamp. This gave me the idea to experiment with gain stacking a bit more in builds. Maybe with integration of a clean blend pot. My first idea was a boost into a tonebender mkiii but I really like the idea of running the ep3 into a barbershop but put a clean blend before the barbershop and after the ep3 so I can blend clean and dirt. I also thought about the thorpy fx gunshot circuit after a boost in a similar kind of pedal. If anyone has an idea on a different interesting circuit I could use let me know. On the shelf I already have bluesebreaker style pedals, a bd-2, timmies and the beforementioned preamp style circuits. Also some Muffs and hybrid tone benders and ring mods.

[Ben N]

I like the Barbershop as an always-on. I leave the gain low and the volume a tick or two above neutral so that ~5-6 on my guitar volume knob is my clean baseline rhythm tone, 7-8 is a nearly clean boost, and 9-10 is light OD boost. People recommend the BD-2 for this, but it never quite worked for me - always too touchy and too bright.