Today I delve into the world of the famous Boss DS-1 distortion pedal and the seemingly endless modifications for it.
Except I'm not doing the mods on a DS-1.
What you see on the left is a First Act MX-510 Distortion pedal. If you're not familiar with First Act, they make very inexpensive guitars, amps and other instruments aimed at children. They also make a higher-end line of guitars that have a decent reputation.
The best First Act story involves Paul Westerberg. He was on tour, stopped into a big-box store to get some shaving cream, and saw a First Act guitar. He bought it on a whim, and it soon was being used on the tour. Subsequently, First Act did a run of Paul Westerberg model guitars, which sold for under $150.
Back to the MX-510. This little pedal is a clone of the Boss DS-1. It went out of production a few months ago, and Toys-R-Us was selling them for (get this) $5 US! I bought two of them. And today I'm going to do some DS-1 mods to it.
There are 2 boards - the main board, and a second one for the controls. They're connected by two ribbon cables.
The first thing I did, and certainly the easiest and arguably most effective is to lift the two clipping diodes, D4 & D5. Don't short them - the pedal won't work if you do. I just unsoldered one end of each and left them in place in case I wanted to do more with them in the future.
The picture shows their location on the board. This mod takes care of the compression in one shot. It also moves the pedal out of the super fuzzy territory back into distortion mode. I really liked the pedal after this. If you do only one mod, this may be it.
This mod reduces the gain of the input transistor, Q2, and noticeably fattens up the tone. Two resistors are changed - R6 is changed to 150K, and R9 is changed to 1K.
This will leave you with a perfectly clean pad or tab to work with. This stuff is cheap - get it online at Mouser.
What still bugged me was the 'fizz' that the DS-1 (and MX-510...) are known for. This is especially noticeable on pick attack and during note or chord decay.
So I did a couple of things to reduce the treble and cut down the fizz. One was to change C7, on the control board up to 470pf. This cut the fizz and treble a fair amount. Interesting to note that a stock DS-1 has a 10pf cap here, while the MX-510 has a 100pf - which tells you that the folks at First Act are aware the fizz is an issue.
The last few changes went after the tone stack in order to flatten out the midrange dip that's prevalent in the stock pedal.
This set of mods evened out the tone and cut down the fizz a bit more. The fizz is still there, but it's not quite as annoying.
I made up a picture with all of the board components identified, which may be helpful if you decide to mod an MX-510.
This little pedal is a lot of fun to use now - it's much more dynamic and gets a nice overdrive tone. You can get these pedals very cheaply, and with a couple bucks worth of parts, you can have a 'boutique' version!