William has been developing pedals and tube amps long before the formation of WMD. A few of them are detailed on this page. The old projects were mainly for fun, but our upcomming products incorporate many of the things we've learned from the projects of the past. This section is under construction, we've loaned some of our pedals out to friends and have yet to get them back for pictures!
The Ultimate Tube Pedal (2008)
This pedal is 7"x4"x2" box size with stuff sticking out the top totalling about 4.5" in overall height. It has six tubes, two transformers, three channels, sixteen pots, zero circuit boards, and two watts maximum output power. It will drive a speaker cabinet or can be used as a preamp to drive a larger amp or directly drive a recording console. It has a 280VDC power supply internally and a rectified 6.3V heater supply. This is the ultimate bedroom practice amp head and an even better recording amp.
The Blue channel is simple: vintage low-medium gain with versatile bass and treble eq. The Orange channel is modern high gain with dramatic bass, mid, and treble eq. The Red channel is experimental medium-high gain, out of phase to the other two, with push pull pot treble and bass eq controls and a bass response/tightness 6 position switch for creating perfect just barely breaking up distortion. In addition, there is a presence control and a line output with a line out tone knob.
The tubes used for the pedal are the 6CG7 as the input driver tube for its really nice drive characteristic and sound. The blue channel uses a single stage of a 12AX7 for a soft overdrive. The orange channel uses three cascaded 12AX7 stages for a hot modern lead channel. The red channel uses a 12AT7 cascaded for a medium high gain. The phase inverter is a nicely balanced Tung-Sol 12AX7 which drives a 12BH7 preamp tube set up as a push-pull output stage.
Video and sound samples will be available soon.
The Parallel Monster (2004)
The Parallel Monster takes a guitar signal and buffers it into four channels. The first two split to a simple creamy overdrive and a nasty opamp distortion circuit. The following two channels are sent to output jacks for connecting other gear. There are then two returns that mix in wit the first two channels. The footswitches control the signal going to the simple mixer. The Parallel Monster lets four seperate overdrives run in parallel, layering themselves upon eachother for some very thick tones!
William hand painted the box with a paper towel and green enamel, then splattered orange and purple with a brush onto the surface. For the lettering, the box was fully masked in painters tape and taken to a laser cutting machine. The laser burnt outlines of the letters and they were painstakingly peeled off with an exacto blade. Then filled with paint. After that dried the remaining tape was peeled off and a sweet textured paint was left. Unfortunately this was incredibly time consuming and was prone to chipping, which is why we now use high quality powder coat to keep the finish everlasting.
The overdrive circuit is the "Blue Magic" circuit from the General Guitar Gadgets website. The distortion is a cascading opamp circuit based on the DOD 250 overdrive. The buffers are JFET design and the mixer is a simple opamp buffer. Each circuit has its own board and created an incredibly messy wiring problem.
This parallel channels idea formed the basis for the Ultimate Tube Pedal.
The Purple People Eater (2007)
This is a very special tube amp designed completely from the ground up by William with a few influences from various tube amp people on the web. The amp is based around a two channel preamp using a 6CG7, 12AX7, and a 6SL7. The high gain channel runs through six gain stages and the clean chanel runs through two. The channels are switched by a relay controlled footswitch.
The special part of this amp is the power section. Instead of using a resistor network on the phase inverter driving the two EL34s, a choke is used and allows more current to the screens of the power tubes. This allows the tubes to distort more evenly and sooner, producing a more saturated tone than the typical long-tail pair found in most class AB amps. This design is based on the Boozhound Labs BHL-15 amp.
The PPE features variable bias for easy adaptation to different power tubes. The output stage and transformer are also specially designed in that they can be switched between Triode, Ultra Linear and Pentode operation. Pentode is the standard output mode since it offers the most wattage and highest efficiency. Pentode is very loud and brighter than the others. Ultra Linear is great for really clean tones, distortion in the power stage is around 2-3%, it is a little softer in volume and tone than Pentode. Triode is my favorite mode, it cuts the highs away in a very musical way and distorts with lower levels of odd-order harmonics. This produces a creamier overdrive like sound as opposed to the more harsh and metally sound of Pentode operation.
The inside of the Purple People Eater is based around a turret board holding the power stage of the amp. The signal path is all point to point wired directly on the tube sockets and pots. All signal path caps are Mallory 150s, as they sound nice and smooth.