The Send and Return sockets of the effects loop have a few tricks up their sleeves. The loop functions in the traditional way, by allowing ‘time’ and ‘modulation’ based effects to be injected after the preamp for better effect definition. There’s also a ‘normalling’ switch inside the Return socket. Plugging out of the ‘Send’ side alone re-routes signal through the unit, side-stepping the cab and voicing options so that it can be run as a valve preamp in front of a physical guitar amp. While this may be a novel approach to isolating the preamp stage, it may be a hindrance to those wanting to use the effects loop as intended.

The Remote socket can interface with both analogue and digital external footswitches. This option may be beneficial to users who plan on mounting the pedal under their pedalboards in a set-and-forget fashion. The Ampster can also be run on a standard centre-negative 9V DC power supply, however this won’t provide the headroom required to run a cab, for those seeking a ‘headless’ rig solution.

Finally, there’s a three-way Voicing switch controlling the roll-off of lower end content. From the ‘performance-view’, having the switch set to the centre position produces a full-range result, which suggests that it’s bypassing the section. Switching to the right, results in a gentle low end roll-off, while switching to the left shifts this adjustment range further into the mids. This is quite an effective way to clean up overly rich, or swampy guitar tones.

CLEAN MACHINE

The Ampster behaves much like a Fender Twin, having a similar responsive interaction when picking notes. It also has enough clean headroom on the input to handle densely processed signals without sounding choked. The Presence control dials in the quack nicely, adding to the performance feedback, and the Bass, Middle, and Treble of the EQ section seem well tuned in a pleasingly additive and musical way — without clouding, or detracting from each other.

With a clean guitar tone the Gain is able to dial in a gentle grit. Carl Martin’s press release suggests a “decidedly British overdrive”, hinting at a Marshall likeness. This becomes more evident once the 12AX7 sees hotter signals from pedals that can push a bit of gain. Overall, it has a nice, round low-end response, with nothing woolly or muddy sticking out. It is responsive, with a smooth picking attack that has a bright, crisp, character that is never brittle.

CABINET RESHUFFLE

The Cabinet footswitch toggles between the 2×12 open-back, and 4×12 closed-back. The selection status of these are indicated by a solid red or green LED which flashes when the pedal is muted. In the 2×12 position, the pedal adds a bright, open responsiveness to the signal, while the 4×12 mode results in a much beefier, intense performance. 

These two options can be further tweaked by way of the Voicing switch, which is able to make subtle or bold adjustments to the overall signal. The left and right positions of this parameter colour the signal in a similar way to that of a close mic’d speaker when pointed at either the dust-cap or outer edge.

These three layers of EQ control — the three-band EQ, two cab sim options, and three-way voicing switch — have a harmonious interplay which make this simple, flexible unit an intuitive and effective piece of gear to use. Carl Martin has provided musicians with an enticing alternative in an increasingly DSP-centric world.