What is it?
Electro-Harmonix The Mole Bass Booster from Nano series. Made in NYC in 2013.
As the one transistor, simple boosters in the EHX family go, here we have the “Bass Booster”. Circuit has pretty much the same topology as all the other simple boosters (LPB-1 and Screaming Bird). The component values are the ones that determine the frequency response and thus, determine if the circuit boost full-range, bass or treble. On full-range, we cut nothing out. On bass, we cut out the high. On treble we cut out the bass. Simple, isn’t it. I was expecting to see the same board as for LPB-1, but no. The Mole has its own design, even though the circuit is still simple, one transistor booster.
Here we have our modern EHX board with most of the design laid out in SMD, while couple of the caps are through hole. And the transistor is a classic TO-92 packaged device too. BC550C. I think EHX has bought those to last a lifetime. At least this type seems to be the weapon of choice for most EHX pedals calling for NPN transistors. Overall, simple and useful. Why?
How does it sound?
Useful due to how it sounds. Want to cut the high end off and give some volume for the lows? For very cheap nano series pedal, this is the way to go. While i don’t see myself using this on my main board anytime soon, i think of the unit as a tool to shape the tones in studio sessions. While it is very good unit, the lows tend to need a lot more power to get amplified. You know, your 50W all tube guitar amp will be louder than your 100W all tube bass amp. In reality, this isn’t exactly true, but due to how we humans perceive frequencies, it might as well be. Due to this, the Mole seems a bit sluggish for its output level, when compared to LPB-1 and Screaming Bird. It could be louder, but still. This one gives you decent kick for your lows while cutting the top end. Usable. Tool.