Earthquaker Devices Monarch Overdrive

30th October 2014 - Put on hold pending investigation :o)

Info about the original:

The Earthquaker Devices Monarch Overdrive is an FET, all discrete dirt machine that will get you some truly vintage and organic overdrive. The Monarch Overdrive is based on a certain UK hard rock amp's input stage that shares the same color as the Monarch's brilliant design. This pedal provides high gains that are largely compression free, for a truly organic and natural sounding overdrive tone that really gets the sound of an overdriven vintage amp. The treble and bass controls are essentially frequency boosters, and not simply the run-of-the-mill roll off filters found in most all overdrive pedals. These controls are centered in the preamp section and really provide some depth to the tone and overdrive characteristics of the pedal. This provides you with a solid bottom end and clear and crisp top ends for rich harmonic overtones that ooze vintage overdrive. This is the overdrive pedal to get for larger-than life fat chord work and a thick and significant bottom end. The Earthquaker Devices Monarch Overdrive can also be used with higher voltages to yield more headroom, a fatter and more focused tone and a wider gain range.

The Earthquaker Devices Monarch Overdrive is one thick and meaty overdrive. Taking the best elements of a vintage UK rock amp, this pedal delivers some balls-out tone. As with other Earthquaker Devices, you have some real control over the tonal characteristics of this overdrive, by boosting frequencies rather than rolling them off. The Monarch Overdrive gives you some real vintage overdrive, but also some real tonal variety when you call for it.

Features:
    Gain: Controls the amount of overdrive
    Level: Controls level of output
    Treble: Boosts highs
    Bass: Boosts lows
    Power: Regulated 9-18v power supply with negative 2.1 mm center barrel

Maestro MPS-2 Mini Phase - ON HOLD

Not the most compact layout (as expected with most phasers) but should fit comfortably in a 125B mounted sideways, and maybe even a 1590B if someone has the patience.

One thing I will say is that until this is verified I wouldn't recommend it being built by anyone who may not be prepared to do a little tweaking.  The effect is slightly different from similar phasers in that it has no resistors between the drain and source of the JFETs and this may be a benefit of the 2N4303 JFETs used in the original.  If you substitute these for 2N5952 or similar as mentioned on the layout, then there is a chance that the circuit will need tweaking to get it working as intended.  I have left a space to add resistors if necessary just to make this easier to tweak for anyone who would like to give it a go.  As usual with these phasers, a matched quad is recommended.

The original BJT transistors were TIS97's which are NPN and around 300 hfe and so I have suggested a 2N3904 or similar as an alternative to those.  Maybe a BC547-550 or 2N5088 would get you in the ballpark a bit better than the 2N3904 so I'll leave that selection up to you.

The original also used 6 x 741 single opamps and so to save space I have opted for doubles.  I'd make sure you socket these as you may want to audition a few to see which double hits the sweet spot for you.

One obvious mod recommendation is leaving out the Oscillator Amplitude trimmer (top) and adding an external pot to control the depth.  If you do want to do that just take the wires for the pot from the holes on the board that the trimmer is connected. 

I can't find any info about the original, or any clips, so the first person to build it and post a vid on youtube will have their vid added to the post! :o)

.. and the schematic:

Opamp 3 channel splitter/mixer ON HOLD

Updated 6th February 2014

I have a TC Electronic G-Force and Eventide Eclipse in the parallel effects loop of my amp and use a rack mixer to keep them in parallel with each other, and so allow me to use them both 100% wet and so avoid having to digitize my dry signal.  I do have OCD about keeping my core dry signal out of the digital domain completely.

But I also have an Eventide Pitchfactor and would like to put this in too, and although the rack mixer can accomodate 4 in and 4 out, adding the Pitchfactor to an already limited rack space would be a pain, so I wanted to make a little 3 channel utility splitter/mixer to use instead of the rack mixer to save 1U and allow me to put two pedal trays in my 6U rack.

I used the splitter scheme you can see at Paul in the Lab, and a generic mixer circuit I found so that everything can be done with one quad opamp.  I may even make this with 3.5mm jacks for the send and returns, make up my own high quality cables and then this will all fit comfortably in a 1590B.  It would pretty much be a set and forget utility for me so I suppose I could even use trimmers instead of pots, set the levels and tuck it away somewhere.  So I thought I'd add it here and it may be useful for others to adapt for their own uses.

Pearl OD-5 Overdrive

Do not start building this one yet as it contains errors. Norwichbadger's amazing footwork on the comments will tell you how to fix yours, if you've built it already. I'll be fixing the layout or redrawing it at some point...

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Olav's relentless requesting took a few things before i got it done. First, he stated that he's happy with the PCB layout he found on the internet. :) And about four months. Told you it was going to be huge.

Transistor pins are once again made for modern everyday transistors like 2N3904, 2N5088 and so on. Original unit has 2SC2240s in it, so if you want to use those, just mind the pinout. Anyway. Here it is. Let's just hope it is correct. And happy easter for everyone!

Catalinbread SCOD

On hold for now, pending verified schematic.

Death By Audio - Soundwave Breakdown

One for the Fuzzynoise-ophiles.  Description of the original:

The Soundwave Breakdown takes the idea of a screaming fuzz pedal and turns it inside out. It uses specially matched transistors turned backwards to get it's bombastic sound. The one knob controls extreme biasing of one of the transistors and the other controls intense filtering. Although this sounds simple the results are perplexing. The combination of allow a vast universe of fuzz | distortion | overdive | buzz | grind | bleeps | synth sounds | harmonies | and soundwave manipulation. The exact positions of the knobs yield completely different sounds for endless great insane fuzz tones.

Video of the 2 knob version, this layout for the 3 knob version with additional volume control.