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DIYRE Colour

Modular Audio Processor
Published December 2015
By Matt Houghton

DIYRE Colour

This novel 500-series module has the potential to be any processor you want!

Some people are put off the 500-series format because they think it too fiddly. If you’re one of them, you’d better look away now, because the DIYRE (DIY Recording Equipment) Colour system is a modular analogue processor platform that lives inside a single 500-series module. There’s so much more to this than subminiature modularity, though: once set up, it’s as far from fiddly as you could get, and anyone who enjoys experimenting with analogue saturation should find it rewarding.

The Perfect Host

Under review are the Palette, a single-width 500-series host module, and a range of the Colour modules themselves. The Palette is a mono, electronically balanced line-level device that can accommodate up to three Colours, and it’s one of two different 500-series hosts offered by DIYRE. The other, announced while I was evaluating this lot, is a mic preamp which can host a single Colour; the preamp itself is intended to be clean-sounding, and you then choose the flavour of (bypassable) saturation you wish to add. I say ‘saturation’, as that’s where this concept started out. As you’ll see, though, there’s more than that on offer, from filters and simple delays all the way up to an 1176 FET compressor clone. The Palette itself stamps no discernible character of its own on the signal, and its only purposes are to route audio through or past the various Colour modules you’ve installed and to adjust the levels of the audio going in and coming out.

This being an open platform, I expect to see further variations on this theme emerge. It’s not hard to imagine a stereo version, for example, or bass or guitar stompboxes that can host Colour modules; and we may well see third-party manufacturers offer Colour hosting options, in the way many already cater for 990-format op-amps. Indeed, the two companies who sell pre-assembled Colour units in their respective territories (Big Bear Audio in the UK/EU and Black Market Modular in the USA) are already developing or offering their own designs. Also, as the two host units and many of the Colours are available either ready-made or in DIY kit form, it would be perfectly possible to build such devices yourself. If you’re thinking of the DIY route, the Palette and the mic preamp are among the simplest self-build projects you could wish to find: all parts are included (with nice features such as DIL sockets to make it easy to place and replace ICs) and the instructions are clear. If you can solder, you’ll be able to build them quite easily. It’s thus a great place to start if you’re thinking of building your own gear.

The Colour modules themselves, some of which are designed by DIYRE and others by third-party manufacturers, vary rather more in complexity, meaning that some are easy builds while others are more challenging. The most complex designs are available only in pre-assembled form, not as kits. More on that later, but first, let’s examine the Palette.

A Refined Palette

The assembled Palette features two variable gain/attenuation stages, one for the pre-Colour input signal and one for the output, and three buttons (with status LEDs) that are used to select which of the three Colour circuits is inserted in the signal path. One, two or all three may be engaged, with the signal running in series from the first Colour via the second to the last. (If you’re on a budget, it’s perfectly possible to start with a Palette and just a single Colour — you don’t need three.) That’s all the control you have on the outside but, as we’ll see, some of the Colours themselves feature internal jumpers and pots which you can tweak to change their behaviour.

DIYRE ColourBehind the front panel is a single PCB, on which is arranged a sparse collection of high-quality components, such as the THAT Corporation ICs, which take care of the electronic input/output balancing and gain stages, and Nichicon capacitors. The card is dominated by three very blank-looking rectangles with a hole at each corner — this allows the Colour daughterboards to be clipped into place via plastic spacers. I found that these spacers were a little too easily broken, but you soon learn how to handle them; they’re also easily and cheaply replaced and a spare is included in the kit. As with all 500-series modules, the signals are delivered to and from the unit via the 500-series host chassis.

Colour Me Good

There’s very little to say about the performance of the Palette itself, other than it executes its intended function admirably: it’s very intuitive to operate, the LEDs and the dial positions tell you what it’s doing, and it sounds very clean. Thankfully then, DIYRE sent me a range of different pre-assembled Colours to try out, so I have something of substance to write about! Without further ado, here are my thoughts on the various modules I tried, starting with DIYRE’s own offerings...

DIYRE 15ips Rev A: It’s important to stress that this Colour is not an emulation of a tape machine plus analogue tape: it’s not adding the noise, it doesn’t apply any low-end head bump, and so on. Instead, it’s all about the saturation effect of analogue tape itself. Being honest, it doesn’t quite do the ‘tape thing’ to my ears, but that’s not a problem: for £35$49, and judged on its own merits as an analogue saturation device, it’s a gorgeous effect on some sources. It was great on blues guitar sounds, for instance, when adding just a little nicely controlled warmth. Via the input pot, I was able to set precisely the point at which things would start to break up.

As with all the modules I evaluated, I found that I wanted to fine-tune the results by applying some EQ, but the unique saturation effect was unmistakable — and rather more impressive than I typically hear in software plug-ins. The 15ips setting also did some very nice things to close-miked snare drums that I felt needed a little more presence in the context of a kit or wider mix. I found it rather less good used on a mono drum bus (it was mono because I had only one Palette and module for testing), because it tended to ‘splat’ on headroom-hogging kick hits. That said, I could certainly imagine it being used to good effect on a parallel high-pass-filtered version of a drum bus or loop.

DIYRE CTX Rev A: This is quite a simple circuit, the price being due largely to the presence of a fairly chunky audio transformer. The idea, obviously, is that you use the Pallete’s input gain and output level controls to drive this transformer into saturation. It’s quite a subtle effect, just adding a hint of low-end thickening, and that makes it great for bass-instrument and drum processing. I can imagine that this would be a very good candidate to occupy the single Colour slot in the CP5 mic preamp, or that a pair of them used in stereo might provide a nice means of imparting just that hint of analogue character to a mix bus.

Three Colour modules — DIYRE’s 15ips (top) and CTX (bottom), and XQP’s Colourphone (middle) — fixed securely in place in the Palette 500-series module.Three Colour modules — DIYRE’s 15ips (top) and CTX (bottom), and XQP’s Colourphone (middle) — fixed securely in place in the Palette 500-series module.XQP Audio Colourphone: The Colourphone is very much a one-trick pony, but it performs that trick with aplomb. Its aim is to recreate the sonic characteristics of an old analogue telephone. Partly, this effect is achieved via an analogue band-pass filter, but there’s also a diode clipper and a telephone transformer in there. It certainly comes closer to achieving ‘that’ character than EQ alone can deliver, though I did find that I wanted to tweak the results once I’d got the signal back in the box. That’s not a criticism of the Colourphone — it’s simply that I could only envisage this being used (in music-making at least) as a special effect, and you’re going to want different things from an effect for different sources and songs.

XQP Audio Colourupter: Described as an ‘optical disrupter’, this Colour’s circuit is taken directly from XQP Audio’s 545 Optical Disrupter. What is an optical disrupter? In essence, it’s a feed-forward optical compressor, the performance of which has been deliberately compromised by sending the audio signal directly to the detector circuit, rather than first converting it to a DC control voltage. The result is asymmetrical distortion. The optical element smooths this a little, though, so you never get into hard-clipping territory. In my tests, the Colourupter sounded great on many signals, but it’s worth noting that it performs noticeably better on individual sources than on more complex material. It sounded great on electric guitar and bass, for example, and on the latter in particular it provided a really quick route to a sort of ‘smooth dirtification’, for want of a more technical phrase. But while it could be used to good effect on individual drums, particularly snare, I found that on a drum bus or room mic the kick too often triggered distortion that made the rest of the kit sound unpleasant. That’s neither a surprise nor a criticism of this design, given what it’s doing, more an observation on its potential uses. (Perhaps placing the aforementioned high/low-cut filter Colour before it in the Palette, and using the whole chain in parallel with the source would yield better results?)

Louder Than Liftoff Pentode: This is one of those modules which isn’t available as a DIY kit. As the name implies, it’s a vacuum tube amplification circuit, and is made by Louder Than Liftoff. It employs a subminiature tube in the circuit and it sounds lovely — there’s none of that syrupy over-warmth you get from cheap valve devices. It’s fairly clean-sounding in general use, but when you wind up the input level you’re greeted at first with that familiar bright ‘edge’ that tubes can offer, before progressing into dirtier-sounding (though by no means sludgy) overdrive. One tiny misgiving I should mention is that when you press a switch on the front panel of the Palette, the mechanical vibration results in an audible ringing from the tube. Brad at Louder Than Liftoff kindly sent a second unit for me to test and the ringing, being at a much higher frequency, was far less annoying than on the first unit I tried. This isn’t really a design fault — Brad tried various tubes, tested various means of damping, and so on — but it seems to be down to microphony in the individual subminiature tubes. However, while the ringing might make direct A/B comparisons more challenging, it lasts only a second or two, and as this isn’t a unit you’re going to switch in and out in normal use it won’t adversely affect your precious audio signal — once switched in it does nice things!

The three other Colours on test, from left to right: XQP Colourupter, and Louder Than Liftoff’s Pentode and Implode.The three other Colours on test, from left to right: XQP Colourupter, and Louder Than Liftoff’s Pentode and Implode.Louder Than Liftoff Implode: This Colour (again, only available pre-built) is rather pricier than anything I’ve described above and quite rightly so, too: it’s so much more ambitious than the others. What we have here is the full circuit of an 1176 Revision F FET compressor in miniature! The physical size means that there are some limitations, of course. Chief among these is that the choice of ratios is limited to 4:1 or 100:1 (the famous all-buttons-in mode), and can only be set by a jumper on the Colour circuit board. Another jumper allows you to bypass the detector circuit, allowing the circuitry to colour the audio but without any gain reduction taking place. The attack and release times and output level are more tweakable, this time by variable pots on the PCB.

The idea, Louder Than Liftoff explained to me, was to make it easy to build several units to create ‘1176 presets’. That does make good sense to me — it’s quite a common trick to use two 1176s in series: one as a compressor, the other as a limiter, for instance. But, while the manufacturers don’t recommend it, a capable DIYer should find it a relatively simple job to wire the Implode Colour into a DIY host with more external controls. As for the sound, the Implode does indeed seem, to my ears, to offer the sound of an 1176. My only wish, if it could be packed in somewhere, would be for a wet/dry blend facility and/or a high-pass filter for the detector circuit — internal controls for these would enable much more precision when configuring your ‘presets’.

A Sound Investment?

I’ve been very taken with the whole Colour/Palette concept. I’ve spent quite some time comparing various saturation devices, and one thing that’s irked me is how expensive it can become to assemble a collection of different ‘flavours’ — I’ll generally only use one or two at a time, but will want to try various options before settling on something that feels right in any given situation. The Colour platform makes this approach both easier and more affordable — much more affordable, in fact, if you’re happy to do a little soldering. You just flick a switch, tweak the levels, listen and decide. Making it yet more of a bargain is that a Primary Colours Bundle is available, giving you a Palette and three of DIYRE’s Colours (15ips, CTX and JFT, which offers transistor-based saturation) at a discount.

As the Implode, in particular, shows, you needn’t limit yourself to saturation. There are plentiful opportunities for manufacturers to build on this whole concept with more capable versions of the Palette: perhaps a stereo version, in which a single button would switch in a matched pair of Colours; perhaps a version with parallel signal paths and a blend control; perhaps, as I mentioned earlier, a version optimised for electric guitar and bass, and so on. And to encourage DIY users to experiment, an unpopulated Colour card is offered for a pittance. Yet, while I certainly hope to see some interesting developments along these lines in the future, the whole concept and execution already works brilliantly: DIYRE’s Colour platform is a great way to add a little analogue character to your setup, or to dip those first tentative toes into the world of DIY. 


Pre-built and DIY Palettes and Colours are available from Big Bear Audio, who are also designing their own Colour-compatible products. See the table below for prices of units described in this review, and visit the Big Bear and DIYRE web sites for details of other modules in the range. All prices include VAT.

ProductPre-builtDIY Kit
Primary Colours Bundle£280£120
CP5 Mic PreampTBA£120


DIY kits and prebuilt Louder Than Liftoff Colours may be purchased directly from DIYRE. Prebuilt Palettes and other prebuilt Colours are available from Black Market Modular.

ProductPrebuiltDIY Kit
Primary Colours BundleTBA$225
CP5 Mic PreampTBA$149
Published December 2015