Hoof Fuzz

This is a great BMP version by Earthquaker Devices with germanium transistors for Q2 and Q3. I really like the mid shift control in the tone section, it adds flexibility and a lot of new sounds.

I used the schematic at bigmuffpage.com to draw my layout. I found info about the germaniums used in different versions in ilovefuzz.com forum:

v1 / rev4 board 2n1302

v1 / rev4 board CV7351 / 2N1308

v2 custom rev5 , 2N1308

v2 / rev5, 2n1308

The consensus being that 2N1308 its the best choice. I used 2N1308 537A I found on ebay. For the clipping leds I used 3mm red as the forward voltage should be the as the 5mm ones for the same color.

House Of Mirrors BASS D.I.

I finished my D.I. Box, its based on the MXR M80 without the distortion and noise gate sections. I won't link the schematic but you can find it on line (google is your friend). It has EQ and Colour, which is a pseudo cabinet simulator. The Colour section only works if the EQ is engaged. With the EQ disengaged its a straight buffered unbalanced output and active XLR balanced output. The main reason I built this its because it can work with phantom power. With the EQ engaged you have a lot of flexible options with boost and cut for Volume, Bass, Mid and Treble.

This is my first designed PCB layout and althought it works pretty well I made some obvius errors, the most noticeable one is that the pots works backguard, so I made it look like a design decision in my decal design. Other important error in the layout its that I didn't check the footprint of some components, mainly the bipolar electrolytics. I also forgot to add VCC pads for the leds so I had to piggy back the connections in some pads on the solder side of the board, I can't take them from the DC jack because they should work with phantom power too.

I'm not really happy with the colour section, it sounds too muddy. As you can see in the next plot it is heavy scooped and a lot of treble attenuation, I'm not sure if schematic its correct in this section, I don't think the original unit works like this.

Tweaking the EQ knobs its possible to get a more useful frequency response. The next plot show the response with bass at min and mid and treble at max:

Ginger Bass Overdrive

In my search for my bass tone I'm looking for a bass overdrive, I want to add a bit of grit and some coloration with no low end loss and I may have found it in the runoffgroove.com Ginger. It is designed to emulate the sound of an Ampeg SB-12 Portaflex. I really like the EQ before the gain section, it has great flexibility. For me this could be an always on pedal with medium gain setting.

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