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TL Audio Crimson 3011 & 3012

4-band & Parametric EQs By Paul White
Published February 1997

Do TL Audio's designs stand up without valves, or is it a case of tubeless tires? Paul White endeavours to find out.

TL Audio have made a big impression creating high‑quality, tube‑based audio processors, and their relatively recent Indigo range (see reviews in the August, September and November issues of SOS) brings tube performance within the reach of most serious project studio owners. However, there's still a pool of end users for whom even the Indigo range is too expensive, and there are even people out there who don't particularly like the sound of valve gear. To address this market area, TL Audio have launched the Crimson series — a range of processors almost identical to the Indigo range, but incorporating all solid‑state circuitry.

The two models on review are the 3011 2‑channel equaliser and the 3012 2‑channel parametric. There are five units in the series at the moment, the others being the 3001 quad mic preamp, the 3021 2‑channel compressor and the 3041 2‑channel, 100W power amplifier (due for release in Spring). All five Crimson models are built into 1U, mains‑powered boxes, and are fitted with both balanced XLR and unbalanced jack audio connectors — even the power amplifier.

Common Features

As with the Indigo series, both units run on mains power, and both unbalanced jacks and balanced XLRs are provided for the audio inputs and outputs. The front panel, high‑impedance instrument jacks have been retained, and these have dual sensitivity to allow them to work with guitars, keyboards and so on. A continuously‑variable front‑panel gain control (affecting all inputs), with +/‑ 20dB of range, is available for level matching, and all three inputs (jack, XLR and instrument jack) may be used simultaneously, though there's no independent control over their levels.

Even though they don't contain valves, these are very heavy units, but unlike the Indigo series, there are no ventilation slots. Even so, they run very cool indeed. The front panels are a sort of 'well‑oxygenated blood' colour with white and orange‑brown legend, while the rest of the case, including the rear panel, is plated. Mains comes in via an IEC detachable mains lead, and the operating voltage may be selected using a recessed switch adjacent to the mains connector.

EQ3011 Dual 4‑Band Equaliser

The EQ3011 is a dual, 4‑band equaliser with shelving high and low controls and two sweep mid‑range controls. It's more like a console EQ than most stand‑alone equalisers (and that may well be where it started its days). At the start of the signal chain are the three input types mentioned earlier, and the gain control. The Hi instrument setting is for use with sources such as electric guitars and basses fitted with passive pickups, though you can plug in high‑impedance mics as well, if you need to. Each channel has its own EQ In button with green status LED, and the mains switch is located at the extreme right of the front panel, also with a green LED. A Peak LED lets you know when you're getting close to clipping.

There are switchable LF and HF frequencies for the shelving filters (80Hz/120Hz and 8kHz/12kHz), and as with the two mid‑band controls, the available range is plus or minus 12dB. Unlike the Indigo EQ, which has switchable mid‑range frequencies, the Crimson's mids are fully variable, which to my mind is rather more flexible, albeit at the expense of accurate stereo matching. The mid‑range bandwidths are preset to provide a fairly wide, musical EQ rather than for precision surgery. If you need to do detailed work, the parametric EQ — which I'll come onto in a moment — is probably going to be more useful to you.


The 3011 drives like a typical desk EQ, but I have to admit that even without valves, it sounds a lot better than most. The fully‑variable controls make it slightly more flexible than its Indigo twin, but the downside is that you lose out on the subtle valve coloration. The sound is tight, detailed and free from harshness or phasiness, giving it more of a classic feel, but given that the parametric costs exactly the same, I think I'd be tempted to send my money in that direction, purely because there's so much more control. Even so, this is a very nice, easy‑to‑use EQ.

3012 Parametric Equaliser

While there are slight differences between the control functions of the Crimson and Indigo 4‑band equalisers, the parametrics seems identical in all respects other than the lack of valves. The 3012 is basically a dual‑channel, 2‑band device, though both channels may be cascaded so that the unit can be used as a single‑channel, 4‑band parametric EQ when required. In single‑channel mode, the output of channel A feeds the input of channel B, though output A still remains active.

All four bands have a +/‑15dB cut/boost range and the frequencies are continuously variable, as you'd expect. Band 2 has a 'divide by 10' range switch, while band 3 has a 'times 10' range switch, in order to provide optimum spectral coverage in both 2‑band and 4‑band modes of operation. A single button switches between 2‑band stereo and 4‑band mono operation, and once again, each channel has its own In/Out switch, complete with green status LED.


The 3012 is definitely the most flexible of the two units I've looked at here (though that's not to demean the performance of the 3011 in any way). Most of the time I tend to need stereo EQ, but even though the 3012 only provides two bands per channel in this mode, there's still plenty of scope for spectral tailoring — and to be honest, I know very few people who can make constructive use of more than two, or perhaps three parametric bands at one time. The 3012 has a clean, shimmery top end that doesn't lapse into harshness as soon as you pile on more than 2‑3dB of boost, and the low end manages to keep the bass sounding tight and well integrated.

Used over a full mix, this equaliser lets you add air and detail to the top end without wrecking the overall feel or tonality, and by the same token, if the bass end needs a bit of help, this can be achieved without making it sound flabby. Similarly, if you have a nasty peak to deal with, simply wind up the Q and dig in — the 3012 can handle it.

When applied to single tracks or instruments, the 3012 has the ability to shape the sound in a very natural way, but at the same time, there's more than enough range to radically change a sound if that's what you need, especially using higher Q settings. As with the 3011, there is a slight sense of missing something — at least if you've had a chance to hear the tube‑powered Indigos — but tubes aside, both these equalisers are very competent performers.


Choosing Crimson over Indigo will save around £200 per unit, and though my own preference would be to hold out for the Indigos, the Crimsons deliver a quality equaliser feel at a price not far above more run‑of‑the mill boxes. What's more, anyone involved in live performance might feel more secure if they don't have to worry whether the valves have survived the last trip or not!

From a marketing viewpoint, the Crimson range makes a lot of sense, as it allows TL Audio to offer high‑end, mid‑price and near‑budget priced studio gear without having to compromise their sonic ideals. As with the rest of the range, the Crimsons look great, they're good at what they do and they're affordable. If you can't stretch to the luxury of valves, the Crimsons might well suit both your ears and your pocket.


  • Smart styling and realistic pricing.
  • Quality EQ sound.


  • After the Indigos, you do miss that little extra tube magic.


The Crimsons offer excellent value for both project studio and live use. If you can't justify the cost of the Indigos, or you don't like the tube sound, I can recommend these professional units at a very reasonable price.