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TL Audio 2 Fat & Fatfunker

Valve Processors
By Paul White

TL Audio 2 Fat & Fatfunker

TL Audio's latest additions to their popular Fat Man range are more versatile than their names suggest.

When TL Audio's Fat 1 and Fat 2 table-top, valve-based compressors were first released, they attained a high degree of popularity, especially with less experienced users, as they were one of the first compressors to include presets designed for a range of different musical sources. Never being able to resist a good pun, TL Audio have followed up these models with the even fatter '2 Fat' valve compressor, and the dedicated guitar preamplifier, the Fatfunker.

Fat Enough Or 2 Fat?

Like many TLA products, the 2 Fat is a hybrid design, in this case functioning as a mono tube front end with a built in compressor, for home and studio recording applications. Like its earlier Fat friends, it has been designed to make dynamic processing as easy as possible, featuring both mic and instrument inputs. The input drive has enough range to add significant tube dirt to the signal, should you want it. The unit boasts a compressor with 15 remarkably good factory presets, covering a range of applications for vocals, keys, guitar and drums. Unfortunately the presets are not customisable, but there are manual controls that enable you to create your own settings from scratch.

All of the presets have been optimised for specific sound sources, but as this is a compressor, all the presets are level sensitive, so some adjustment of the input level is necessary to get the best results. The manual provides a brief overview of the applications that each preset can be used for, but given the lack of tweakability of the presets, it would be helpful if they documented the exact settings used, so that you could recreate them using the manual controls and then fine tune from there.

There is also a 'Fat EQ' button that applies a preset EQ curve to beef up and enhance the sound — which is extremely useful for warming up vocals or giving your guitar a more 'chunky' feel. It can also work well in conjunction with the bass roll-off function, giving the higher-mid tones some added punch.

According to TL Audio, there will soon be a new digital output option — it doesn't come as standard — which is sensible, as you won't be paying for digital expansion if you don't need it. For those who do need it, it will be based on the same 24-bit/96kHz card that you'll see on the Ivory range and can be fitted easily by the user.

In contrast with the original desktop Fatman, the 2 Fat is a standard 19" 2U rackmount design. It feels sturdy and businesslike and, as befits a near relation of the original Fat Man, it has a rosy-red face. The input stage is a solid-state, low noise amplifier offering low distortion and maximum bandwidth. This is fed through to the second stage, based around an ECC83 triode valve to provide the classic valve sound and progressive overdrive characteristics, so you get the best of both worlds — low noise at the front end where it matters and variable tube drive later in the chain.

Controls And Connections

The controls are grouped by function and flow from left to right, following the actual signal path: Input, Process, Output. Although most of the connectors are on the rear panel, the input panel includes an unbalanced (TS) instrument input with a gain control, allowing the straightforward connection of guitars, keyboards and so on without the need for a DI box. Four black buttons toggle the selection of high/low gain for mic- or line-level inputs, plus there's a 90Hz bass roll off, -30dB mic pad and 48 Volt phantom power.

The 2 Fat includes a range of compressor presets that have been well chosen, but don't be scared to try them on different instruments: the vocal preset seemed to work equally well on guitar!The 2 Fat includes a range of compressor presets that have been well chosen, but don't be scared to try them on different instruments: the vocal preset seemed to work equally well on guitar!There are also two small LEDs: a green one, that displays the amount of valve drive, and a red one to indicate an input level peak that's close to clipping.

Compressor program selection is via a large, rotary switch, labelled with the 15 presets. You cannot override the preset parameters in any way other than adjusting the input gain, as the manual controls are only enabled when the dial is switched to the 'manual' position. Fortunately though, the presets seem pretty good.

To the right are the manual compressor controls, comprising the usual threshold, ratio and gain make-up, along with four small buttons to toggle between slow/fast attack, slow/fast release, hard and soft knee and compressor on/off. The only difference between this and some other compressors is the way that the threshold control works: the control starts at a 'plus' value in the counter-clockwise position, and decreases to a 'minus' value as you rotate the control clockwise. The 2 Fat manual states that TL Audio "think this is logical, whereas the common method of turning the control 'down' to achieve more compression is not". This essentially means 'more clockwise' means more compression, which should be intuitive to musicians who are inexperienced with studio recording.

The output section includes an output level control, the Fat EQ switch I mentioned earlier, and an illuminated VU meter, with two associated switches — one of which enables you to meter either the output level or gain reduction, whereas the other adds +10dB to the level meter, making the reading more meaningful with certain soundcards and interfaces that require a hotter level.

On the back of the unit is a standard XLR microphone input, a balanced line input and a balanced output, the latter two on TRS jacks. The line Input and output are compatible with both balanced and unbalanced signals, with sufficient input and output gain control range to cover all conventional signal levels without requiring -10/+4dB switching. The instrument input is unbalanced and has a high impedance, as it is specifically designed for use with passive guitar and bass pickups.

Practical Testing

This unit is designed to work well as a front end for recording all vocal and instrument sources, including DI'd guitars and basses, though it works equally well as a mix-warming tool. I devised a few practical tests to see just how flexible it was.

Firstly, I plugged my guitar into the instrument input on the unit and then took the output to my guitar amplifier. This added a full, rather pleasing tone, but turning up the input gain a notch brought a gorgeous, creamy valve overdrive. Such distortion can sound nice when subtle. Should you want to push things further, the higher you make the distortion level, the more obviously gritty it becomes. Of course, this worked best running through a guitar amplifier — if monitoring via a desk or a computer you'll want to use speaker simulation to tame the high end.

The guitar compression presets were good. The first added a light compression that just polished off the sound slightly, while the second preset compressed a lot more assertively, giving a fuller and more tonally dense sound. In fact, many of the presets — whether intended for guitars or, for example, vocal — brought out something useful in the sound of the guitar, so don't be afraid to try all the presets on all sources just to see what you can get.

On vocals, I found the 2 Fat worked really well. As well as smoothing out level changes, the vocal presets added a subtle warmth, with slightly more high-mid in the overall sound, and seemed to really deliver that extra edge needed to help the vocal sit well in the mix. The 'compressor on' switch was useful here, enabling direct A/B comparison between the pre and post compression signals.

The input gain could also be used as a creative tool when experimenting with vocals, as well as with different instruments. The input gain is variable between +16dB and +60dB for the mic input, and-20dB and +20dB for the line input, allowing a wide range of sources to be handled properly, but there's also enough headroom to deliberately overdrive these sounds. Increasing the input gain pushes more signal into the valve, thus generating harmonic distortion. At the same time the output level can be turned down to maintain a reasonable output level, so you can go anywhere between almost clinically clean, via warm, to overtly dirty. Increasing the input gain setting will also tend to push the signal towards and possibly over the compressor threshold setting, so this control will have a pronounced effect on the amount of compression taking place, especially in the preset modes where the manual compressor controls are inactive.

In manual mode, the results are just what you would expect, but operation is still simple as the attack and release times are switched, rather than completely variable. The manual controls will cope with a threshold between +10dB and -20dB with compression ratios between 1:1.5 and 1:30, which means it can be used for applications from gentle compression through to hard limiting. At the end of the chain, gain make-up of up to +20 dB is available to restore any level lost through the compression process. In either manual or preset mode you need to check the meter in gain reduction mode to see just how much gain reduction you're applying so you can adjust the input level (or threshold in manual mode) to get the best result.

Why Do We Like The Sound Of Valves?

Valve (or vacuum tube) compression yields a particularly special sound that tends to flatter the signal source and is often used to counter the supposed sterility of digital workstations or recorders. The reason valve equipment sounds so distinctive is mainly due to harmonic distortion and natural compression that increases at higher gain settings. As the signal through the valve is increased, it generates a particular type of subtle and musically pleasing distortion (mainly second harmonic distortion) that is difficult to emulate precisely using solid state circuits. Valves also tend to naturally compress an audio signal, particularly when the input signal level is increased to the point where the valve is driven into soft clipping. An important point about this unit is that the valve circuitry is a proper high-voltage design — not a 'marketing' tube running from 12 volts that does little more than warm up the inside of the box. Many designers also believe that valve circuitry produces less offensive dynamic distortion under real signal conditions as the circuitry tends not to rely on as much negative feedback as solid-state designs. Whatever the reason, the 2 Fat sounded gorgeously warm on just about everything I tried it with.

2 Fat Conclusion

The 2 Fat is a lovely compressor, with something to offer both the home studio user and the professional. The hybrid circuit design provides a clean, low-noise signal, with the flexibility to dial in just as much valve warmth as you need. Offering both preset and manual operation, it combines versatility with simplicity — though I'd prefer it if the manual controls could be used to tweak the presets. Although the digital option isn't as inexpensive as I'd hoped, the 2 Fat itself is sensibly priced, given its pedigree and polished sound.

Stand-alone compressors are having a hard time of it in these DAW-dominated times, but by combining a compressor and a good quality mic/line/instrument preamp section, TL Audio have provided a solution that works well with computer recording systems. If you want a good quality front end that doesn't cost the earth, and you like the idea of a unit that takes some of the pain and hassle out of setting up a compressor, the 2 Fat might just be the solution you've been looking for.


Styled and packaged in the same vein as the 2 Fat and also using hybrid circuitry, the TL Audio Fatfunker might sound like it should be a bass guitar effects pedal, but in reality it is a fairly conventionally set out recording front end comprising a mic/line/instrument amp, a manual compressor section, with hard or soft-knee modes, and a four-band, console-style equaliser, with switchable shelving frequencies at the two extremes, two mid bands with fixed bandwidth and four switchable frequencies per band. There's also a very simple 'one knob' gate to kill noise during pauses. As with the 2 Fat, the output stage includes a moving-coil meter that can be set to monitor the input level, the output level, the output level +10dB (for feeding those hungry soundcards) and compressor gain reduction. Switches in the master section place the EQ pre- or post-compressor and there's also a link button that works in conjunction with a rear panel jack to allow the compressor sections of two linked units to track correctly in stereo.

The Fatfunker is not as aggressive as its name suggests. In fact, the EQ turned out to provide a very crisp and focused sound, which will be useful for a wide range of studio applications.The Fatfunker is not as aggressive as its name suggests. In fact, the EQ turned out to provide a very crisp and focused sound, which will be useful for a wide range of studio applications.By way of connectivity, the instrument input is on the front panel, with the line inputs and outputs being available on both jacks (unbalanced) and XLRs (balanced) on the rear panel, alongside the XLR mic input. The line input may be switched between two different sensitivities to accommodate +4dBu or -10dBV sources. Power is delivered via a fused IEC connector, and there's also a slot for the digital expansion card.

The front end offers similar facilities to the 2 Fat but uses a four way rotary switch to select mic, mic with phantom power, line or instrument sources. A drive LED shows you when there's enough front end gain to get the tube stage cooking and there's the same peak LED, low cut filter and mic 30dB pad arrangement as on the 2 Fat. At first glance, the compressor looks similar to the manual section of the 2 Fat but closer inspection reveals that it has four switchable attack and release rates rather than just two. The manual tells us this uses a transconductance gain element, rather than the more common VCA. In most respects it seems broadly similar to the compressor section of the 2 Fat but in this case there are no presets. It does however have a TRS jack side-chain insert point for adding an equaliser, enabling it to be used as a de-esser, and there's that useful gate which, despite its knob coming to the right of the compressor, is correctly located in the signal path before the compressor. A single LED shows when the gate is closed and setting up requires only the setting the threshold at which it opens, as the attack and release times are preset. Separate bypass switches are available for the compressor and EQ sections but in order to disable the gate, you simply set its threshold to minimum.

Although the equaliser has no mid-band Q controls to qualify it as parametric (the bandwidth is set to a gentle two octaves), the lower-mid can be switched to operate at 250Hz, 500Hz, 1kHz or 2.2kHz while the upper-mid works at 1.5, 2.2, 3.6 or 5kHz. At the low end, the shelving filter can be set to 60, 120, 250 or 500Hz, while the high end can be set to 2.2, 5, 8 or 12kHz making it pretty flexible. Up to 12dB of cut or boot is available in each band so at high boost setting you may need to turn down the master output level to avoid clipping.

Weight Watching

Despite its name, the Fatfunker is a pretty well-behaved front end, and you have to push it pretty hard before it turns nasty. For example, if you drive the mic amp so that the tube drive light comes on, you can get that slightly compressed, slightly warmed up tube sound but it isn't too hyped. Similarly, while the compressor adds the impression of mid-range when used heavily, it actually sounds reasonably transparent at sensible settings and doesn't mess up the high end the way some more heavy-handed compressors do.

Like the 2 Fat, the Fatfunker includes balanced and unbalanced inputs as it can operate either as a mic preamp or as a high-class DI for guitar and bass.Like the 2 Fat, the Fatfunker includes balanced and unbalanced inputs as it can operate either as a mic preamp or as a high-class DI for guitar and bass.When it comes to EQ, the result is crisp and focussed with none of that cheap EQ 'blurring', though I have to admit that I found the switched frequencies a bit limiting. The choice of a wide bandwidth mitigates this to some extent though and, to be fair, you probably don't want to be doing too much surgical EQ during recording, as it is very difficult to correct later if you get it wrong. As a general tonal shaper, the EQ section is actually very musical-sounding and works as well with instruments as it does with voice. Guitar or bass DI'd through the Fatfunker comes over as tight and detailed with no audible background noise and the combination of compression and EQ can really help get your source sound a lot closer to what you want to hear in the final mix. The tube drive adds thickness and warmth to instruments without going so far as to make them fuzzy (unless you deliberately ignore the clip LED), so as an all round front end, the Fatfunker comes over pretty well. The only area in which the lack of flexibility shows is in the gate section, which closes fairly quickly. This is ideal for vocals, but when used with a noisy guitar, you can often hear the gate closing before your note has died away fully — something that could be avoided by offering a choice of long and short release times.


Both these units behave predictably and in a very musical way, as we've come to expect from TLA's outboard range, with, the 2 Fat's presets being particularly helpful for less experienced users. As a general purpose input channel, the Fatfunker is really very good and is also sensibly priced, so don't let the slightly aggressive name put you off; this isn't some hyped-up overdrive monster but a really sweet and versatile front end. 


  • Good-sounding hybrid design.
  • Variable valve coloration.
  • Very easy to use.
  • Digital output option available.


  • Gate action is sometimes too fast for certain instruments.


The Fatfunker doesn't really deliver the attitude its name suggests but in my book this is a bonus as what TL Audio have produced is a very straightforward, good-sounding input channel that has the benefit of variable tube warmth.

TLA 2 FAT £410


  • Good-sounding hybrid design.
  • Variable valve coloration.
  • Very easy to use.
  • Digital output option available.


  • No way to modify the presets (or to find out what settings the presets use).
  • Digital card adds significantly to the cost.


  • Sensibly priced.
  • Very musical with both vocals and instruments.
  • Quiet signal path with adequate headroom.
  • Digital output option available.


  • Gate action is sometimes too fast for certain instruments.


The Fatfunker doesn't really deliver the attitude its name suggests but in my book this is a bonus as what TL Audio have produced is a very straightforward, good-sounding input channel that has the benefit of variable tube warmth.

2 Fat £410, Fatfunker £586
Prices include VAT.

TL Audio +44 (0)1462 492090.

+44 (0)1462 492097.

Published February 2007