Gakken SX-150 Review: Taming the Beast

(Editor's Note: I finally deleted my Myspace accounts, but I wanted to save this review. So, you're getting a recycled post instead of something new. I've been busy learning the Juno and falling in love again with the Xio.)

When I accidentally discovered the SX-150 in late summer, 2010, I felt compelled to own this handful of cheap analogue goodness. The first thing you notice is the size: yes, it really is a handful, and not much more. (Note: I wrote that sentence before my Monotron arrived). The DIY part of the project takes about 15 minutes and fills you with the vague satisfaction that you have understood some Japanese. (Yes, they still ship it with the magazine). And you also have now created an analogue synth: a cheap, plastic synth that you play with a stylus smaller than an IKEA pencil. Oddly enough, the SX-150 is also capable of creating some very lovable low end. What you’ve got sounds good, but is a pain in the palm to play in a meaningful way.

I doubt that anyone has that has owned a SX-150 for more than a week has left it stock. Much of what has been written about the SX-150 concerns modifying it in order to impose some control over what notes you play, taming the beast using whatever means available. Indeed, the SX-150’s popularity appears to be directly related to how easily it can be modded / hacked. Honestly, some of these mods (especially the midi mods) are way beyond me, but then I have trouble telling the difference between a circuit board and a billboard. At the same time, some mods cost more than the SX-150 itself, which seems a little self-defeating. Most SX-150 owners have probably seen the Novation BassStation sequencing video (http://www.synthtopia.com/content/2010/01/06/sequencing-the-gakken-sx-150/). However, it has also been pointed out that it is a little silly to have a $400 piece of gear driving a $40 synth. Still, the BassStation video demonstrates best what needs to be done with a SX-150: plug it in to whatever you’ve got, or plug whatever you’ve got into it: I plug it into a SansAmp GT2, crank the bass and get an amazing tone. With the Monotron and the Punk Cosole, you have the Poor Man's Modular. Connecting the PMM to the Electribe promises to be great fun.

My Mods

As you can see from the photo, I haven’t done much: the main thing was removing the original speaker, which really should be the first mod everyone makes to their SX-150 – it is a piece of crap that does not do the synth justice. With the extra space, I was able to install a ¼” jack (which is a much hotter signal than the stock 1/8”) and The Big Black Knob.

i. Terminal A to the left of the ribbon

ii. Terminal B to the stylus connection

iii. Terminal C to the right of the ribbon

Advantages:

- Don’t have to play with the stylus: instantly less geeky

- Can set a note & leave it: drone, excellent with tremolo or flange

- You get to play with a Big Black Knob

Disadvantage:

- Sound is constant, thus making Attack and Decay redundant. And as the Pitch envelope barely works and the Cutoff only works from 12:00 to 5:00, you are really only left with the LFO Rate/wave to shape the sound. However, if you ask me, that is enough: get the LFO and the pulse-wave working together and you’ll understand.

I promised myself not to cover this synth in stickers, but I really messed up the resonance switch hole: I wanted to replace the switch with a pot, but while trying to remove the switch (which was solidly soldered in place) I made a right mess of the circuit board and had to abandon the idea. However, I had already made the hole big enough for the pot, so I had to cover it up somehow, and if you have an eight-year-old daughter, Hello Kitty stickers are easily available.  

Peace

TJ