Friedman BE-OD

Friedman makes some really nice stuff and BE-OD was probably the hottest pedal in 2016. Being a big fan of the hot-rodded Marshall sound, I had to jump on that train one way of the other. I considered buying the pedal, but the good people at FreeStompboxes.org forum managed to reverse engineer it and one of them even produced a pro-quality PCBs, so I went the DIY route once again and decided to build the pedal myself. The PCB came from PedalPCB.com and is really nicely done. At the time of writing, they have updated the PCB to be even better and made a cool PCB that unifies BE-OD with Dirty Shirley circuits.

Build

The build is fairly simple to complete. I used PedalPCB’s build docs as a reference for drilling the enclosure and everything fits well. There’s no room for a battery, but I don’t need it, so it’s ok. Should you need a battery, it’s probably possible to squeeze one below the bypass switch if you move the switch up, and maybe everything else for a bit. Earlier versions of the PCB were designed for 1/8W resistors that I didn’t have so I mounted my resistors vertically, but the latest PCBs should be able to take 1/4W resistors horizontally. As far as the part selection goes, I used nice Nichicon electrolytics, a mix of Wima and Nichicon film capacitors and a mix of Dale and no-name resistors. For op-amps I used NE5332P for U1 and U2 and TL072ACP for U3, as I had those at the moment.

Finish

For design I went with a hot pink enclosure I bought long time ago and waited for the right project. I though it would be cool to host a brutal sounding pedal in a girly box with colorful knobs. So I got some yellow and green knobs, a blue footswitch cap and a large green LED. I drew a vector design for the label and had it printed on the self-adhesive transparent foil, commonly used for taxis or shop window labeling. Around the LED I drew an eye, making a nice little play on the “Brown Eye” name, or in this case “Pink Eye”. It turned out pretty cool I think.

With a piece of very fine sandpaper I sanded the surface of the LED to make it diffuse the light more evenly and glow in all directions.

Results

BE-OD is really a one-trick-pony but it’s very good at delivering very aggressive hot-rodded Marshall tones that work equally good for heavy rhythm and lead playing. In most cases it sounds great with everything at noon. Having the ability the control the high and low frequencies at two different stages of the circuit is very cool and allows us to dial in the perfect amount of bass and treble – make it fat without making it boomy, make it roar without making it shrill. The four EQ controls are really nice to have but they are there only to tune the pedal and match the guitar and amp being used. They don’t dramatically change the character of the pedal. Gain control is similar. It somewhat increases the saturation, but the character of the sound remains the same throughout the range of the Gain control.

Mods

BE-OD is a relatively complex circuit that leaves a lot of room for experimenting. With so many choices it’s easy to get lost, so I focused on two parts of the circuit and used gold-plated sockets so I can play with different components:

  • Clipping diodes. There are three places in the circuit where diodes clip the signal, producing distortion – a pair of red LEDs in the feedback loop of U1.2, a pair of BAV99 (or a quartet of 1N4148) in the feedback loop of U2.1 and finally a pair of red LEDs between U2.2 and U3.1 in shunt-to-ground configuration. Using different types of diodes can change the amount of distortion, compression and the character of distortion. It’s easy to tell by the way the the last pair of LEDs glows that they clip real hard, so they are the first candidate for experimenting with different options. Later stages generally clip sooner than earlier stages, so going backwards is a good strategy. LEDs produce distortion that’s different than other diode types and has slightly harsher or aggressive character to them, that I typically associate with distortion solid state amplifiers. One way to change the character of clipping is the swap the LEDs for different diode types. I experimented with BS250 MOSFET (wired as S -> D+G) in series with a germanium diode to polarize it. The MOSFET has a forward voltage drop around 1.9V, so combined with a Ge diode, it comes up to around 2.1V which is very close to the forward voltage drop of 2V for a typical red LED. However, MOSFETs clip very differently, producing warmer and more gradual clipping that resembles how overdriven tubes clip. This also reduces the amount of distortion, so I had to dial the internal gain trimpot slightly higher to keep the pedal in high gain territory. Another benefit of this configuration is that it increases the range of the Fain control and makes the pedal sound more like a regular plexi at lower gain levels.
  • Capacitor C13 chops the high end harshness off and can be increased if you find the high end to be too rough. I used a stock value of 120pF (ceramic instead of mica used in the original), but I put socket to be able to experiment if need be.
Final Thoughts

It would be really nice to be able to control the mids like on the Dirty Shirley pedal. Luckily, after I completed my build, Bugg from PedalPCB.com started selling “Brown Betty” boards that unify BE-OD and Dirty Shirley circuits (which are mostly the same anyways) and it features the additional Middle control. I would suggest building this version as it offers the best of both worlds with bigger footprint as the only downside.

Comments
5 Responses to “Friedman BE-OD”
  1. Jeff Smith says:

    Cost mainly the reason for not buying the actual thing. Thanks for the suggestions. I’ll look for a kit online with all the parts. They do exist right? I’m new to all this.

    • bancika says:

      I’m not aware that anyone sells kits yet, but things are changing fast, there will probably be one soon enough.

    • bancika says:

      You can try asking at freestompboxes.org, there’s a thread for BE-OD. Someone might be able to help you.

  2. Jeff Smith says:

    /How did it turn out and sound? Any chance you are building them for others? I’m so not electronically inclined to make something like that and would pay for it?

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    The idea behind this site is to share my experience with Do It Yourself approach to guitars, amplifiers and pedals. Whether you want to save a couple of bucks by performing a mod or upgrade yourself instead of paying a tech, or want to build your own piece of gear from scratch, I'm sure you will find something interesting here. Also, this is the home of DIY Layout Creator, a free piece of software for drawing circuit layouts and schematics, written with DIY enthusiasts in mind.