Plexi Drive / Velvet Fuzz

The Velvet Fuzz is basically a Plexi Drive with two switchable boost sections in front of it, so I built mine to work as a standalone Plexi or with either of the boost sections engaged. I made my own layout for the boosts sections and used the IVIark layout for the Plexi.

To be able to fit two boards inside a 125B box I had to go creative and mounted one of them under the lid and other under the top side of the box.

This is my layout for the Velvet boosts board.

MXR Phase 90

I built this using the layout by Harald Sabro at sabrotone.com. For it to work properly you need a matched set of JFETs, if you are in Spain like me, you can do as I did and buy a matched set from retroamplis.com. It worked right the first time and I'm loving it.

It is a tight fit for a 1590b but if you are tidy it should be no problem.

Simple CabSim

Schematic

This is a nice and simple cabinet simulator designed by Lart. You can find more information about it on diysompboxes.com. What I really like about this cirtcuit is that it only does one thing and it does it well, without external controls this is a perfect solution to drop in a preamp stompbox or a D.I. box.

Alternative transistors

I have simulated it in LTSpice with pairs of PNP / NPN from different series. In the next plot you can see the frequency response using the specified BC560C/BC550C pair, 2N5087/2N5088 and 2N3906/2N3904.

As you can see, 2N508X come pretty close to BC5X0C, with 2N390X having a smoother curve.

Veroboard layout

I have drawn a vero layout to build it, its a bit croweded but smaller than I was expecting. I recommend using a multilayer ceramic for the 1uF capacitor.

My build

This is my build, I used 470pF and 220pF in parallel beacuse I didn't have any 680pF, and 2N390X pair being the only pair I have at hand.

This sounds really well with a 1W PUNCH amp, I'll post a video when I have it boxed up.

11/09/2014 Update: I have uploaded my LTSpice file for anyone who want to try it. Right click on the link and choose "Save as": SimpleCabSim_yeraym_vulcanofx.asc

StoneGrey Distortion

Shoot the Moon Tremolo

Mxr Headphone Amp + ROG Condor Cab Sim

This is  my silence practice rig, it is an mxr heaphone amp (layout by mirosol) and a runoffgroove Condor Cab Sim in one 1590bb box. Each one has its own input and output jacks, but I used switched jacks and the output of the cab sim is internally connected to the input of the headphone amp when neither of them has a cable connected. This is not one of my best looking builds but its the most used one.

I did my own layout for the Condor, and included a switch to select between condor and marshall simulator. I used a bicolor led.

Deep Blue Delay with TAILS mod

Update 03/2015: see this post for and alternative daughter board.

I have modded my Deep Blue Delay because I really think that having tails is an essencial feature for a delay pedal. I took the idea from the Merlin's Small Time Delay. By adding a FET analog switch at the input of the PT2399 we can bypass the input of the IC while getting the output in form of tails.

The analog switch is in a daugther board. Terminals A & B are interchangeable in the main and daughter boards. Using a DPDT on/on and a 3PDT footswitch we can select between buffered bypass with tails and True Bypass.

Using the layout by Mark the mod include adding a cut, moving one leg of a resistor one row down and moving one 1uF cap. The A and B wires have to be soldered in the middle of the board instead of on the side but there is enough room for them without moving other components.

This is the layout with mods.

This is the daughter board with the off board wiring.

I built mine without the volume mod, and this is how it's looking, with a few scratches on the paint but I like it.

In this pic you can see the daughter board next to the output jack.