Audio Simplified Pedal Pusher

This box aims to provide all you need to use your pedals with a mixer or audio interface.

As we explored in some depth in our SOS April 2021 cover feature (https://sosm.ag/mixing-with-pedals), guitar pedals needn’t be the preserve of guitarists — they can be truly inspirational mixing tools as well. While plenty of pedals have now been emulated pretty well in plug‑in form, there remain many that haven’t, notably many distortion boxes, and the hands‑on control of hardware can also lead you down very different creative paths than software. Pedals, though, tend to be much higher impedance devices than studio outboard gear, especially at the input. They usually work at lower signal levels too, so as to match the output from a typical guitar pickup, and most have unbalanced inputs and outputs. Simply hooking them up to an audio interface’s line‑level I/O risks driving them into distortion.

This collection of problems is what Canadian company Audio Simplified’s Pedal Pusher devices are intended to solve. There are currently two products in this range: the Pedal Pusher itself, and the more compact and affordable pedal Pusher Mini. We were sent the full version, and for this one you have a choice of using it as a desktop/pedalboard unit or buying it with rack ears to turn it into a 1U 19‑inch rackmount device.

Design & Functionality

The idea of the Pedal Pusher is to put in one box everything you need to hook your pedalboard up to a mixing console or professional audio interface, so that you can use your stompboxes in the same way as you would any other piece of studio outboard gear. In other words, it takes care of converting your audio interface’s low impedance, balanced output to an unbalanced, level‑ and impedance‑matched feed into your pedal, so that the pedal receives a signal similar to what it would expect from a guitar. It also takes the pedal output and passes that back to your DAW as a balanced, line‑level signal. It caters for two mono send/return loops, though as I’ll explain it’s a little more versatile than that.

Conveniently, it incorporates a pedal power supply, with six isolated outputs. Inside the case is a low‑noise, universal voltage, 50/60 Hz power supply, which powers both the active circuitry for the pedal loops and the six isolated, high‑current (1A each) pedal power outlets. The latter feature selectable voltages (9, 12, 18 and 24 Volts DC), as indicated by small LEDs, and these are selected using a screwdriver‑controlled switch to prevent accidental switching. A further over‑current LED warns you if any pedal is trying to draw more than one Amp, which is a nice touch. Some pedal power cables are included in the price, but it’s worth noting that each PSU output is wired centre‑pin‑negative (the most common format for pedals), so if you need centre positive you’ll need to use a swap‑over cable (not supplied). With all this on board, you could conceivably site the Pedal Pusher on a large pedalboard, to keep the unbalanced cable run nice and short, and use a longer balanced feed to/from your DAW. (The Mini Pedal Pusher omits the pedal power supply section).

The rear panel hosts the two pairs of balanced XLR audio connections for interfacing with your DAW or other line‑level device.

On the rear, you’ll find two sets of balanced XLR I/O connections for connecting to your audio interface’s ins and outs, and on the front are the two sets of unbalanced quarter‑inch jacks which provide the To and From connections for your pedals. This arrangement allows you to run two mono pedals/chains or one stereo or mono‑to‑stereo pedal/chain. The output impedance is 15kΩ, to approximate a guitar output, and the input impedance is 1MΩ, which is typical of guitar amps, and the designers point out that the outs will also work as reamp outputs — you don’t need a return signal to use them.

Each input also has a Pickup push switch for emulating the impedance of passive or active guitar pickups, and a high‑frequency variable EQ, available only in the passive position, emulates the loading of a typical guitar cable. While this control has only a modest range, it is very effective, with the fully clockwise position being the brightest‑sounding one, as you’d expect. After the pedal return, the signal is converted to a low‑impedance, balanced feed at the correct level to feed line devices, such as studio outboard gear or an audio interface.

The two pedal loops each have a polarity‑invert switch alongside their Active/Passive switch. Channel two has two additional routing switches that allow for feeding both loops from a single XLR input or both outputs from a single DI source. With the Loop Src button pushed in, the Pedal One signal is delivered to both of the front‑panel To jacks, which is useful if using two pedals or amps in parallel, fed from the same source. With the DI Src switch pushed in, the front panel From jack of Pedal One feeds both of the rear‑panel XLR outputs.

Performance

The Pedal Pusher is one of those products about which it is difficult to write a long and involved ‘how it performed’ section, because conceptually it is so simple. But that’s no bad thing in my book! It has been thoughtfully designed and it is well made, and I can confirm that in practice the Pedal Pusher sounds clean and does exactly what is expected of it, without any fuss. The two routing buttons on Channel two are a practical and useful addition, and so too is the cable‑emulation EQ control. I can’t fault the pedal power supply section either; a few simple tests with a multimeter confirmed that the pedal PSU outputs are indeed fully isolated, and in use they powered my pedals very happily without introducing any noise or hum.

Conveniently, it incorporates a pedal power supply, with six isolated outputs...

I tested the Pedal Pusher as a means of hooking pedals up to my Logic Pro X DAW, via my audio interface. Logic, like most modern DAW software, has a dedicated I/O insert plug‑in that allows you to select which physical ins and outs it addresses on your audio interface, and it can also ‘ping’ the circuit to detect and compensate for any latency. Helpfully, then, when nothing is plugged into the front panel of the Pedal Pusher, the To and From jacks are normalised — this makes it super easy to check that your insert routing is correct without you having to connect a pedal. The Logic I/O plug‑in configuration can be saved as a preset, so if you want to insert a pedal you simply drop the I/O plug‑in into the appropriate insert slot. Once you’re set up in this way, there should be no need to change anything other than which pedal or pedals you decide to plug into the front panel. That said, it’s still advisable to ‘ping’ each time you change/add/remove pedals, as not all of them will have the same throughput delay time.

To put a few numbers on the performance, the balanced I/O can accept levels of up to +24dBu, with +4dBu being the nominal level. The output level is again a nominal +4dBu but can accommodate up to +27.5dBu into 600Ω when balanced or up to +22dBu unbalanced. The frequency response is essentially dead flat to just over 0.1dB from 20Hz to 20kHz and the noise level is a respectable ‑90.5 dB A‑weighted, with a THD quoted as 0.00847 percent and intermodulation distortion as 0.011 percent.All in all, Audio Simplified’s Pedal Pusher is a practical and well thought‑out piece of kit that makes integrating pedals into your mixing setup very convenient. It should hold appeal for any guitarist wanting to make use of their pedalboard in a home studio context, or to mix engineers wanting to put these little boxes of inspiration to good use.