Mark Allen Earnest

Aspiring to play like Gilmour and solder like Cornish

News & Upcoming Events:

11/1/2011 I joined two collegues from Entology at the start-up consulting firm Identity Works LLC

3/19/2010 Luke Denver was born

11/1/2008 Entology purchased by PricewaterhouseCoopers

7/10/2007 Ryan Matthew was born

9/18/2006 I started my new job as an Identity Management Consultant with Entology Inc.

6/30/2006 Jen and I closed on our new house

5/27/2006 Jennifer Schell and I were married. Look for pictures to be posted here.

3/27/2006 I presented a talk entitled "Authentication, Authorization, and Identity Management" at the 2006 PSU Security Day


Guitars 'n 'at

I've been playing guitar since 94, mostly as a hobby but once with a band that I assure you no one who did not go to Penn State New Kensington in 1997-1998 has ever heard of. Recently I have begun to really get into achieving that perfect and elusive guitar tone I have always wanted (potentially making up for my average playing ability). This seemed a perfect way to use the geeky soldering and electronic skill I acquired during my ham radio building phase.

The Guitar

The guitar I have always had is my 1994 sunburst, made in Mexico Fender Stratocaster. I've improved this guitar (in my opinion) beyond that of the more expensive American Strat by adding locking tuners, Callaham Bridge, Fender Hot Noiseless Pickups, and improved electronics. Having played both, I really prefer the Mex Strats (although their quality seems to vary more from guitar to guitar than American Strats do), and with a little extra money can be made into a truly great guitar. Probably not worth as much on the resale market, even with the additions, but I bought the guitar to play.

I have recently acquired my dream guitar, a Rick Turner Model 1. I will get some pictures up soon.

The Amplifier

While my ideal amp would be a classic Hiwatt or one of the newer Reeves, I would be blowing my family out of the house with one of these. Plus I really should admit to myself that I am not playing gigs in large stadiums (yet) or actually anywhere anymore these days. That in mind, I still want that warm tube tone and enough headroom to handle my pedals and still have a clear tone. I did a lot of research and found exactly what I wanted, the Peavey Classic 30. I put in a set of JJ Tubes and it sounds great. There is a quiet hum that I have not been able to get rid of yet, but it is not a big deal as I am not recording from it.

The Pedalboard

All of my effects were built by me either from kits (mostly from the wonderful General Guitar Gadgets store) or from scratch with parts sourced from Mouser and Small Bear Electronics. I have not yet designed any of my own circuits mostly because I'm trying to get accurate reproductions of classic (and often out of production) pedals and because I am nowhere near that good yet. I am however getting more into experimenting on the pedals I have build and making some modifications.

Let's look at each of these effects in order

GGG Mod-Wah

This started its life as a totally unmodded GCB-95. I ended up completely gutting it and installing the GGG Mod-Wah board. I installed a 6-way selector for the different tone capacitors and a switch for swapping the input and outputs to get the high pitched modulation needed to achieve the "seagull" sound heard on Pink Floyd songs like Echoes and Is There Anybody Out There. For the all important inductor, I decided to give myself the most options possible. A classic Halo inductor is mounted on the board itself, and two Fasel inductors (Red and Yellow) are glued to the base of the base of the enclosure with a toggle switch between them for selecting one or the other. A 3 way rotor switch on the side will select between the Halo, Fasel (whichever is selected by the toggle switch), and both the Halo and Fasel in series for a more full wah sound.

BYOC Fuzz Face

This is electronically the simplest pedal I've built, but the second hardest for me to get to sound right. I spent many hours trying different transistors (various combinations of germanium and silicon) before I settled on a matched pair of NPN Germanium OC140. I set the bias by ear then was later pleasantly surprised it was the exact recommended voltage. This is a great pedal for Cream (White Room) or Hendrix style tones. Cleans up very well with the volume knob and when backed off it sounds very much like a treble booster (which is good because my overdrive is usually set to boost bass frequencies).

Custom Compressor with GGG Orange Squeezer and Ross Compressor

I had a Dynacomp and I liked it, but I wanted something both a little smoother and something with a little bit more aggressive "squashing" tone (think Steeley Dan solos or early Mark Knofler). I took some inspiration (or more accurately, ripped off the idea) from AnalogMan and put both a Ross Compressor and Armstrong Orange Squeezer into the same pedal. Also, since my pedal chain is getting a bit long, I decided to build an IC Buffer to pass the signal into before it hits either compressor. This is kept always on making this the only pedal on my board that is not true bypass. The rational for placing this in the compressor is that you do not want a buffer before the Wah or the Fuzz Face as this will adversely affect both pedals operations. I may put one at the end of the chain as well, but I am not positive about that yet. Those of you electronically inclined will notice that when ordering parts for the Ross board, I learned the hard way the difference between axial and radial electrolytic capacitors. Rather than deal with my mistake by ordering the correct parts and waiting to build it, I just made them work.

Baja Real Tube Overdrive

This is truly an undiscovered gem in the world of guitar effects. I was considering getting a BK Butler Tube Driver (like everyone else looking to get close to Gilmour's recent tone) but the price tag was a bit high and I accidently ended up with a pretty cool "all homebuilt" pedal scheme going on. Searching for alternatives to Tube Driver I ran across the above linked thread on and was intrigued. Bajaman sells these pedals himself but I really wanted to build one. He was kind enough to sell me a pre-etched and drilled circuit board (two actually, I expect to start wanting a second one of these someday). I had some difficulty drilling the enclosure since unlike every other pedal I have built, this one has all the jacks and controls mounted right on the board requiring more precision than I normally can achieve with a drill. This pedal has fast become my workhorse overdrive and really gives me the "crunch" sound I have been looking for. I drive it with a ECC83S (12AX7) pre-amp tube from JJ Tubes. It really shines as an overdrive providing some additional power to the Big Muff Pi, but it also sounds very good on its own.

GGG Big Muff Pi

I've built this to the vintage Triangle Version Specs. This is also the first pedal kit I built. This is my standard workhorse distortion box for when I need something heaver than the ITS8 and Baja Tube Overdrive and do not want that Fuzz Face Tone. Think Comfortably Numb solo type tone (notice how so many of my tonal references are Pink Floyd related?). I generally do not ever tweak this one. I have the tone, volume, and distortion set where I want them and just kick it on when I need it.

GGG ITS8 Overdrive

This is a good pedal, but it honestly sounded much better with a solid state amp rather than a tube amp. This overdrive (clone of the ts808 Tube Screamer) can give me anything from a clean signal boost to a warm tube sounding overdrive to a raw screaming overdrive. I've done the standard GGG mods with a three way selector switch to go between asymmetric diode clipping, LED clipping, and no clipping (just boost). I've also added a switch to give a strong bass boost. Since the addition of the Baja Real Tube Overdrive, this pedal is primarily used as a booster or a mild overdrive with the LED clipping.

GGG Phase 45

I replaced an MXR Phase 90 with this pedal for a couple of reasons. (1) The Phase 90 is not a subtle effect by any means, and I like to have a subtle modulation effect to kick on when I am not using a stronger one like the Flanger (or the Univibe I am building), (2) This was the last non-homebuilt (and non true bypass) pedal on my board, and (3) I accidentally plugged the Phase 90 into my 18v power supply and it really did not like that. Like the Phase 90, it is a one trick pony that does that one trick very well. It has a very unique sound which does not overpower the tone.

BYOC Analog Chorus

Chorus is a pretty common modulation effect, and one that can be used to subtly color a tone without overpowering it (I'm looking at you, Flanger). This pedal is a kit from BYOC which produces a very warm, analog sounding chorus which I really enjoy. As I am clearly running out of space, this sits on top of my Mistress Flanger. The circuit seems to be based loosely on the classic Boss CE-2, but I think it has a distinctive sound on it's own, sort of a cross between a CE-2 and an EH Small Clone.

Homemade Electric Mistress Flanger Clone

Unlike the kit pedals, I started this one with just a PCB from GGG and an increasingly hard to obtain Reticon SAD1024 delay chip from SmallBear. From there I sourced all the parts (mostly from SmallBear and Mouser) and built something that is not quite to the normal specs, but still very flanger sounding. I experimented a lot with this one, probably more that I should have since I blew the SAD1024 once and almost melted the resistor after the voltage regulator when I inserted the opamp backwards). This pedal offers everything from a mild flanging for clean strumming to a strong modulation for soloing. It does not suffer from the noise and volume drop that the original has. I need to spend some more time adjusting the trimpots to get better control over the speed, but overall I am happy how this turned out.

R.G. Keen Neovibe

This is not a clone, this IS an exact circuit reproduction of the classic Univibe made famous by Jimi Hendrix, Robin Trower, and of course Gilmour. This board was designed by the godfather of the DIY pedal scene, R.G. Keen who was kind enough to help me debug some of my issues while building this extremely complicated pedal. This pedal was build using a circuit board from GGG and parts sourced from Mouser. I probably spent more time on this pedal than all of the other ones combined. Using all discrete circuitry and an incandescent light bulb surrounded by optical sensors to produce an organic phasing effect, this is my favorite modulation effect. However, it is something you don't want to overuse as it is also very distinctive and not really subtle.


I love echo (we have established I am a Pink Floyd fan) but I hate how digital echo sounds. I love the warm decay of a good analog or tape echo and that is just what I get with this. I've recently added a toggle switch to double my echo time (at the expense of audio fidelity). This pedal gives me really good Another Brick In the Wall style syncopated echo sounds, however it reacts very oddly to the flanger which seems to severely cut the level of the repeated notes. Still have not figured that one out, but not a huge problem as I do not often really want to use the two together. This pedal also had the most complicated board, and probably took the longest to build if you don't count the times I rebuilt the flanger over and over again.


The layout is always subject to change, and is currently where it is as a result of many hours reading up on pedal placement theory, and many more hours of ignoring what the experts had to say on the matter and figuring out what sounded good to me. The Wah is first because it really needs to be since I like to use it with the Fuzz. The Fuzz otherwise would be first because I want the purest signal going into it (too many buffers can affect the guitar volume knob cleanup). The compressor is next mostly because I use it to control the volume into the overdrive and distortion boxes. The overdrive is after the Muff because I like to give the muff a little extra boost occasionally. The phaser is often considered a filter effect and placed with the Wah. I personally think it sounds better in the modulation section at the end. At any rate I do not like the sound of a phaser before distortion. The Flanger is placed after the phaser mostly for physical layout issues, I don't use the two together so it really does not matter. The echo is of course last so I get a true echo of the generated tone. The entire board is wired up with George L's cables. And if you are really curious, the board itself is a plywood door to an Ikea desk with metal handles I bought at Home Dept (along with the roll of velcro).