D*A*M - Ezekiel 25:17 Bass Distortion

"The path of the righteous man is beset on all sides by the inequities of the selfish and the tyranny of evil men. Blessed is he, who in the name of charity and good will, shepherds the weak through the valley of darkness, for he is truly his brother's keeper and the finder of lost children. And I will strike down upon thee with great vengeance and furious anger those who would attempt to poison and destroy my brothers. And you will know my name is the Lord when I lay my vengeance upon thee." - Jules Winnfield, Pulp Fiction - Taken from Ezekiel 25:17.

Yeah, Pulp Fiction's cool! Well, the D*A*M Ezekiel 25:17 pays tribute to one of the most famous scenes in the film:

Great name for a pedal don't ya think? Well, David Main (The Captain over at D*A*M) has offered the schematic for this pedal. So if you wanna build one - you can :-)

Firstly some info on this pedal:

"This monstrosity has so much bottom end it will surely move the planets from their celestial homes!

Ezekiel is a very high quality bass distortion amplifier that will cater for all your bass overdrive/distortion needs. Many flavors of distortion are available thanks to the unique four-position "Distortion flavor" rotary switch, from bright punchy valve like tones to raging heavily sustained Distortion. The Blend control adds further clarity and width to the tone and assures a true deep bass response by allowing you to dial in as much or as little of your clean signal as you feel necessary. Ezekiel is like no other Distortion effect available today it is not based or modified after any other effect it is the one and the only! no others come close.

It is a common problem for bass players that the choices of distortion effects available are limited by the fact that most guitar based effects will lose low end frequencies when used with bass. Not with Ezekiel, it was designed for bass players and will still maintain low end punch even when tuned down to C. Whether you use your fingers, thumb or a pick Ezekiel will always give you the control and clarity you need, from a smooth subtle growl you to an insanely saturated wall of fuzz, Ezekiel has the means to deliver.

Even though Ezekiel was originally designed for bass use, if your guitar is of the seven string rarity or you prefer to tune your axe down to D or C Ezekiel can give you the extra wide bass punch that you need.

THE CONTROLS
"Gain"- sets the amount of gain available
"Filter" - passive tone filter that assures top end attack or solid bottom end
"Level" - set the output volume
"Blend" - mixes the full distortion signal with your bass guitar clean signal
"Distortion Flavor" switch- dials through four different styles of distortion from subtle overdrive to seriously saturated fuzz."

And a demo video of the Ezekiel in action: 

Well, here's the schematic (drawn by David Main of D*A*M holiness himself!) [note - correction by IVIark]:

So, looking at the schematic we've got an opamp/diode based clipping circuit which has basically been optimised to work around the bass guitar's frequencies (the 470r/10uF network on the opamp clipper make sure all the availiable frequencies are amplified, unlike in something like a tube screamer where only freqs above 720Hz are amplified). The Blend control just allows you to add in a bit of the unaffected clean signal, this is a great idea and is used a lot with bass overdrives and distortions - it allows you to keep a nice plump bottom end :-D and we all like those now don't we?

As you can see you're going to need a rotary switch for this one (for the diode switching) - a single pole quad throw is what you need!

And here's IVIark's brilliant vero layout for it here (visit http://tagboardeffects.blogspot.com for many, many, many, many (I really mean many) more of IVIark's vero layouts!):

Here's the freestompboxes.org forum topic for reference and build reports: http://freestompboxes.org/viewtopic.php?f=7&t=13223