The Asterion Overdrive is our take on the Klon overdrive with more dynamic headroom, more top end sparkle, and an extended low frequency response that is great for bass guitar.
Back when Broughton Audio did custom designs we made a couple of Klon overdrives for guitarists. While they sound great for guitar, they leave a lot to be desired for bass. On paper it sounds like a great idea for bass: an internal charge pump for huge headroom and a clean low passed parallel path. However, the gain is still too much for bass, making the clean transients clip the op amp stage with nasty distortion, and the germanium diodes squish the signal too much so that there is no articulation. There is nowhere near enough bass, and the top end is too dark. With some experimentation, we've taken this great overdrive pedal for guitar and made it great for bass.
The first major change was to tune the low frequency response so the bass comes through. Like so many other guitar pedals, the frequency response is basically a bell curve centered between 700 and 1k Hz, with a taper off in both directions. While this may sound great for guitar, it's pretty bad on bass without some clean blend. Even the clean parallel path inherent to the pedal is not enough.
The second major change was to reduce the gain of the summing amplifier to allow the clean dynamics to shine through, and to reduce the saturation of the dirty path to allow more of a touch sensitive response. The added benefit of reducing the gain at this stage is allowing more high end to come through so the signal is not so muffled. No longer is it a sustain inducing guitar pedal, but a clear and punchy drive with low end depth and top end clarity.
The third major change was to re-tune the low passed signal so that the clean mids come through. The original Klon is low passed at 100 Hz. This is fine to retain some deep subs, but bass guitar really needs clear mids to cut through the mix. For this reason the clean section low pass has been raised to 1 kHz.
The final major change was to expand the EQ section to include a bass knob. The existing treble control is an active baxandall topology. With some clever design work, we put in the bass half of the classic bax stack without messing with the original tone profile of the treble control. The bass knob covers over 30 dB of range for 100Hz and below, ensuring you can dial in plenty of low end as needed.
With all of these changes, the heart of the Klon still shines through. It is a germanium based overdrive with a unique gain section that warms up the drive signal as gain is applied. It has the parallel clean path to allow low frequencies to punch through. It has huge headroom due to the unique power supply scheme. And finally, the tone controls reach a wide spectrum of highs and lows to be able to fit your playing style.
The pedal requires a 9 volt DC power supply (not included). The DC supply should be a standard Boss style connector, center negative polarity. The current draw is approximately 10 mA.
Asterion Overdrive has a true bypass switch.
Dimensions: 4.77" long x 2.6" wide