MXR Distortion +

This is a classic. The MXR Distortion + (aka Distortion Plus aka D+) came out in ’74. It is a rather simple circuit that bears great similarities to the DOD 250 pedals. Those came out more or less at the same time. Pedal aficionada and historians seem to be still debating who came first.
The version I got is second hand and all I can tell you is that the stamp on the inside of the lid has the Dunlop logo, and Dunlop bought MXR in ’87.
Another hint is on the outside: A sticker with the CE logo as well as the “Electronics don’t belong into the trash” picture, so I assume this is a fairly recent model. The WEEE (that European law that regards e-waste recycling) was implemented 2012-2014, so I guess this pedal is less than 10 years old.
So much for the model.
From holding it, I can say that it feels very solid – the weight is a lot more than expected. The Yellow is a beautiful shade and it’s applied with a rough texture, giving it a matte look, a great contrast for the black writing. Of course it comes with side jacks (Why?).

Operation is 9V, and my unit has the common center negative barrel jack, there is a battery option, too.
Simple pedal, simple description. Nothing special so far, but in the early 70’s the pedal market was not that big and you did not need to stick out from the crowd. Actually, I think the MXR was the first pedal to have the word “Distortion” written on its shell, so that actually was some novelty back in the day.

In 1974, when they were released, the Idea of hard clipping was brand new, and the setup of the pedal is very simple. Same as the DOD 250, the MXR Distorion Plus uses a LM741 operational amplifier chip to drive a germanium diode into hard clipping, all controlled by a single gain knob.

There are some similarities to the Klon, regarding the frequency response along the travel of the gain knob. Look at this handy graph, made by electrosmash.com :

With rising gain, there is a massive increase in the area of 1.5kHz. For guitar use, this will push a lead passage nicely through a mix. For bassists, this will mainly be conceived as a drop in the low end. It does not render the Distortion + completely useless for the low end fraction, but it means that one will have to watch out not to ride the gain so high that the high mids bump gets too out of hand.
Switching on the Distortion + with the gain at minimum will already yield a sound that is a little fuzzy around the edges. Increasing the gain will go from there to a raw sound that introduces heavy compressed clipping. There is a certain amount of touch response, although it cannot compete with pedals that are known for their responsiveness. As a bassist, there is a “soft cap” to be found just a bit past noon, where you can feel that the bass will not keep up with the rest if you increase it further. You get a metallic clank by then, and a very aggressive sound. The rawness of the sound is somewhat accentuated by the lack of tone controls.

The idea of using that pedal was quite simple: Imagine it’s the seventies and music is evolving rapidly. Black Sabbath has put out their fifth album and heavy metal is a thing, Lemmy Kilmister is still with Hawkwind, but Judas Priest has just entered the scene of signed artists and released Rocka Rolla. Things are wild and the future is looking even wilder. There is still a decade to wait until Spinal Tap takes amps to 11, so you are stuck with your amp on 10, craving more.
The MXR Distortion + is the thing you were looking for. That pedal takes your overdriven amp and sends it further. A lot further. This is what you were imagining in the wilder dreams you had about guitar sound.

Fast forward five full decades and into the lab of a bass player that is obsessed with dirt pedals.
The bar by which a pedal gets measured here sits in a completely different position, and measured by that bar, the first impression is that the MXR Distortion+ is quite boring. The way the grit comes into my signal feels quite artificial when I run it through my standard setup and try to use it as the device that generates the overtones, harmonics and dirt. The limited throw of the gain knob does not allow for a massive wall of distortion as long as I’m not prepared to sacrifice my low end to get there. Pedals have come a long way, and the expectations have also climbed to higher levels to meet the raised standards. Frankly speaking, I don’t really find a way to include the Distortion + into my setup that makes any sense. Of course I could use it to drive another pedal, the Origin Bassrig for instance, into another level of drive – but I would really prefer to get some kind of tonal control over that stage of the gain, and especially since there are loads of pedals out there that offer those options, I don’t really feel the benefit of using that particular pedal. If you are planning to play music from that era and look for that particular sound, I guess that firing the D+ into your driven amp might have its merits, but the cork sniffing pedal snob in me sees less of a classic here and more of a dated design that has been replaced by much better works of pedal building art and is completely redundant at this point.
It’s a bit like a Volkswagen Bug. Something that’s nice to see on the road, but you really would not want it as your daily driver.