Richard Waghorn tests the TL Audio PA3001 alongside some of the best mic preamps available and discovers a good combination of price and performance.
TL Audio's new Crimson range of products makes their well‑thought‑out designs more affordable to us than ever before, by leaving out the valves and replacing the relevant circuitry with solid‑state devices. The layout and operation are otherwise the same as for the acclaimed Indigo series, itself a low‑cost alternative to the Classic series.
TL Audio's PA3001 4‑channel preamp is essentially a stand‑alone rackmount unit housing four mic preamps and a mains power supply. Continuously variable input and output controls and switchable high‑pass filters (90Hz), plus phase reverse and 48V phantom power, are fitted to each channel. Input to each preamp is via a rear‑mounted female XLR socket, electronically balanced and suitable for low‑impedance (150‑600Ω) microphones. Phantom power, for microphones that need it, is switched from the front panel independently for each preamp.
The input gain is variable from 10‑60dB; the associated peak LED blinks when you approach clipping. The LED begins to illuminate at +6dBu, and is full on at +16dBu with 10dB of headroom remaining. A high‑pass filter can be switched in to remove rumble and low‑frequency noise, and a phase reverse switch is fitted — this is useful in maintaining the correct relationship between microphones, particularly on close‑miked drum kits or in other multi‑mic situations. Finally, the variable output attenuator can be set to the optimum level for the next piece of equipment in the signal path (tape machine, mixer, processor and so on). The output appears on the back panel, at either an electronically balanced male XLR connector or an unbalanced jack socket (+18dBu maximum).
I found the PA3001 easy to install (there's no external power supply) and the levels were quick to set up. The single LED indicator, although minimalist, functions intuitively. The high‑pass filter is set to ‑3dB at 90Hz (12dB/oct), a sensible place to have a fixed roll‑off, although I miss the luxury of a variable filter. A phase reverse switch is one of those things that you never need to use until you haven't got one, so it's good to have one available. The output level range allows this preamp to be used in a broad variety of applications: live, it can be used to provide four low‑Z mic inputs to a mixer with indifferent mic amps; in the studio, its most obvious application is as a one‑stop, direct‑to‑tape microphone stage to get the cleanest possible signal to tape. Many small studio owners, myself included, are using high‑quality outboard to feed the recorder and a compact budget mixer to monitor back off tape. One useful addition would be to have instrument input jack sockets on the front panel for DI'ing guitars and unbalanced high‑impedance microphones.
Now for the subjective part. I am convinced that it's in the choice of microphone and preamplifier (performance permitting) that a good recording is created. A great recording, for me, must focus not only on the sound, but also the performance. The detail and subtleties must be heard, but the silence within which the sound is being produced should be sensed too. Ultimately I should be able to close my eyes and visualise the musician playing in front of me. The best preamps I have used to achieve this to date are the Neumann V76 valve amps designed in the late '50s. So with the TL Audio preamp under my arm, plus a couple of mics, I visited fellow sound engineer Mick Dolan, who possesses an arsenal of the aforementioned valve amps. I listened to the PA3001 alongside the V76, and also compared it with a Mackie mic input stage, while Mick sang and strummed an acoustic guitar.
As expected, the V76 sounded rich and beautifully smooth at the top end. The TL Audio channel fared well, although it sounded a tad thinner and harsher at the higher frequencies. Overall, the sound was somehow less well defined, though in all honesty the TL Audio preamp is probably less coloured than the V76, which includes both valves and transformers. The Mackie preamp, which I've always thought of as being good for a budget‑to‑mid‑price console, sounded in its turn discernably less well defined than the PA3001.
At just under £470, this unit offers four preamp channels at a similar quality to what you'd expect to find in a good (but not esoteric) pro desk. It offers a significant improvement over most of the budget consoles that I've heard, and, as TL Audio units usually are, it is solidly built and well constructed. Those who want to improve on the performance available from a budget console without the expense of a more sophisticated esoteric design should find this a strong contender.
- Value for money.
- Solid construction.
- Ease of use.
- No instrument input.
A cost‑effective mic preamp that fills the niche between typical low‑ to mid‑price console mic preamps and expensive top‑end designs.