Review: Aphex USB 500 Rack

Sam and Dave, Morecombe and Wise, corned beef and cabbage. There are some combinations that just work. And others – Donnie and Marie, lager and lime – that make your heart sink. So now that Aphex has released its 500 USB frame combining 500 module flexibility with USB connectivity, the question on everyone’s lips is, “Lennon and McCartney or John and Yoko?” Alistair McGhee has the answer. 

The Aphex USB 500 Rack is built into a sturdy well-finished steel frame and is made in America. The unit has slots for four 500 series devices and a frontpanel control section two slots wide. The Aphex takes an IEC mains lead and has a frontpanel power switch. Power it up and the Aphex logo above will be illuminated in tasteful green. 

Above the power section are two 0.25in jacks for headphone outputs, each with an independent volume control and at the top of the section a monitoring volume control with associated mono and dim push buttons. These buttons share the Aphex green illumination when engaged.

The twin headphone outputs carry the same signal but have independent level control, watch out as you reach to move your headphones from one socket to the other; I managed to switch the rack off while doing so. You, of course, will be more careful.

Using the 500 USB with OSX is easy – plug it into a Mac and away you go. On an ageing iPad 2, plug it in via the USB camera kit and fire up GarageBand and hey presto it works. Beware though, a couple of other iPad apps didn’t work so well. For Windows you need a driver – download it from the Aphex site, install and then plug in the rack and all should be peachy. I had two Windows systems to hand – one running 7 64-bit and the other running Windows 8.1. Plugging into 7 64-bit brought an interesting issue into focus. Windows mapped the Aphex’s multiple outputs in terms of speakers, so my headphones were centre and sub. This is because the Aphex allows you to work with the main outputs separately from the headphone outputs. I also found that my foobar media player preferred using Asio.

My Windows 8 system has Pro Tools 11 on board and I was half expecting a bit of hardware wrestling to get the Aphex to work. As it turned out, reading the note in the manual about leaving your existing hardware plugged in did the trick and once the driver was loaded it worked first time without a hitch.


As you have a combined USB interface and 500 rack, your routing is a little more complex and indeed more flexible than your average standalone rack.

Each module (apart from slot 1) has a choice of three inputs – the XLR on the back of the device itself, the neighbouring module to the left, or a USB input from the computer. So you plug something in to the XLR, you take the output from the previous module in the rack or you take a feed from your DAW.

We’ll start with the last of those options. One of the really nice features of a 500 system is using the modules as inserts in your software mix. My USB 500 came from MSL Professional and they kindly included some of the Aphex 500 modules to garnish the basic rack dish. I began with the EQF 500 – a 21st century take on an Aphex classic from the 70s.

Aphex provided some basic instructions on how to do this in Pro Tools and I followed along without too much trouble. If you don’t want to bother with adding a bus then just add an aux track to your mix. Then route the output of your original track to the module input in the rack and route the module output to your Aux track. Don’t forget to switch your module to USB input, and that’s it. In Reaper why not avail yourself of the glories of ReaInsert, which allows you to do proper send and return insertion on your track without using any more screen ReaLestate. Sorry about that.

I should say that I found the EQF 500 a very musical equaliser. It’s three band and the top and bottom sections are switchable between shelf and bell functionality.

You also get sweepable high and low pass filters. The EQs offer plus and minus 12dB. It’s probably symptomatic of being a certain age but I do enjoy the physical process of fingertip processing; I know that in itself adds nothing to the result but I can’t help it, there will always be a place in my heart for the physicality of audio.

Having worked through the insert process you begin to see the power of melding your USB interface with a 500 rack. All the routing and plugging takes place down your standard USB cable. This allows you to make the most of digital flexibility while enjoying the analogue benefits of external processing.

Of course, the other big deal is on the input side. If you can afford the choicest plums from the likes of Prism Sound or Metric Halo then maybe you don’t worry too much about the quality of your mic amps, but for the rest of us the chance to pick and choose our mic amps is an opportunity not to be missed.

I had the choice of three Aphex units: the A Pre 500; the dual RPA 500, replete with valve technology and the J Pre 500, with Cinemag and Jensen transformers on board.

My 500 preamp of choice is the Grace Design M501, but this is hardly the place to start a mic preamp punch-up beyond saying that Aphex’s 500 series gear is tidy, as we say in Wales. Hopefully we can do them more justice when space allows, especially when the new Project 500 module arrives.


So, in summation, the Aphex is definitely a Jagger/Richards sort of combination. In terms of convenience, flexibility, and usability it is a hard product to beat.

The boards are awash with demands for bigger models and there’s a real buzz around the product. I’m just sorry now that the French didn’t get more of a grip on the USA back in the day. Pourquoi? Well, because losing rack screws, like death and taxes, is a certainty, and while metric options abound the 4-40 screws found in the Aphex are very hard to find. [MSL Professional assure us they would be able to source them from the factory without too much trouble – Ed].