M-AUDIO Tampa

May 1, 2004 12:00 PM, By Karen Stackpole

The Tampa is a Class-A, solid-state preamp that takes an innovative approach to achieving tubelike characteristics. According to the manufacturer, the Tampa's Temporal Harmonic Alignment (THA) technology controls the phase alignment of added harmonics in a way that preserves the original sound while emulating tube characteristics in high-gain situations. M-Audio asserts that the effect goes beyond the midrange enhancement that tube circuitry typically offers and affects the entire frequency spectrum equally.

In addition to the new technology, the 2U, single-channel Tampa offers a symphony of bells and whistles at a reasonable price. These include a dual optical-servo compressor, a digital output with selectable sampling rate, and variable input impedance.

A SHINING FACE

With its chicken-head knobs, sturdy toggle switches, VU meters, and metal handles, the Tampa exudes vintage class (see Fig. 1). At the far left are the power switch and a 48V phantom-power switch with associated red LED. The input section, outlined in black, includes a Neutrik combo jack that accepts balanced and unbalanced ¼-inch and XLR inputs, and a toggle switch to select microphone or instrument level. Above that is the variable input-impedance selector, which offers four choices: 300ž, 600ž, 1.2 kž, or 2.4 kž. The gain control gives you 34 dB of level, with an additional 20 dB of boost available at the flip of a switch. To the right of the input section is a switchable highpass filter that rolls off 12 dB per octave beginning at 80 Hz.

Next is the compressor, which includes a bypass switch and controls for threshold (-20 dB to +20 dB), ratio (1.1:1 to 10:1), attack (1 ms to 10 ms), and release (250 ms to 5 seconds). The left-hand VU meter shows the amount of gain reduction.

To the right of those controls are a switchable -20 dB pad, which affects the analog output only; an output VU meter that doesn't reflect the setting of the pad switch; a phase-inversion switch; a red LED that illuminates when the signal reaches +26.5 dBu (4 dB below the digital-clip level of +30.5 dBu); and the sampling-rate selector, which offers rates of 44.1, 48, 88.2, and 96 kHz.

The rear panel has 24-bit dual-mono S/PDIF and AES/EBU digital outputs on RCA and XLR jacks respectively; separate ¼-inch and XLR analog outputs; and a receptacle for the lump-in-the-line power supply (see Fig. 2). The ¼-inch analog output jack accepts balanced TRS or unbalanced TS cables. Both analog jacks pass signal simultaneously.

PRODUCT SUMMARY
M-Audio Tampa mic preamp/compressor $799.95
FEATURES	4.0
EASE OF USE	4.0
AUDIO QUALITY	3.5
VALUE	4.0
RATING PRODUCTS FROM 1 TO 5
PROS: Temporal Harmonic Alignment feature. Dual optical-servo compressor. Overdrive feature with 20 dB boost on input and 20 dB pad on output. Highpass filter. Variable input impedance. Digital output. Variable sampling rate. Phase inverter. CONS: Compressor's maximum attack time is too fast and minimum release is too slow. No makeup gain on compressor. Enhanced low-end sustain can reduce clarity in some sounds. High-end transients sound dynamically flat.
Manufacturer
M-Audio tel. (800) 969-6434 or (626) 633-9050 e-mail info@m-audio.com Web www.m-audio.com

DIRECTLY SPEAKING

I tested the Tampa next to a number of other preamps — a Universal Audio 2-610, a Peavey VMP2, a Grace Design 101, a Langevin Dual Vocal Combo, an FMR RNP8380, a TubeWorks DI, a Digidesign Digi 001, and the preamps in a Mackie 1202-VLZ mixer — to get a sense of how it sounds against a broad range of popular products. I used the preamp and compressor functions on acoustic guitars, vocals, and percussion; I checked the DI on electric guitar; and I finished up with a comprehensive loudspeaker test. For the recordings, I used Neumann KM 184 and AKG C 3000 B microphones and tracked to Digidesign Pro Tools LE and a Sony PCM800 digital multitrack. I was assisted by engineers Steve Orlando and Myles Boisen.

For a rowdy session with the band Jingle Punx, I ran the output of a distorted Fender Stratocaster through a Line 6 PodXT into the instrument input on the Tampa. Then I ran the Stratocaster-PodXT combo into a TubeWorks DI going direct into the Digi 001 preamp/converter. Both signals were sent digitally into Pro Tools.

Orlando, the engineer on that session, was initially frustrated that the Tampa's 20 dB pad couldn't be applied to the digital output, because he wanted to overdrive the signal and maximize the tubelike effects of the THA circuitry. As a work-around, he cranked the Tampa's input gain and squashed the signal with 20 dB of gain reduction through the optical compressor before it hit the digital output. This method was very effective for getting the tubelike sound he wanted, and it enabled the Tampa to compare favorably to the TubeWorks DI, with the added advantage of clearer and slightly brighter highs.

M-Audio informed me that there is less headroom in the digital signal than the analog signal, which is why the pad isn't applied to the digital output. The 20 dB gain-boost switch at the input is meant to be used in conjunction with the 20 dB pad at the output so that the input gain can be driven hotter without overloading the analog output. This trick allowed me to reap the benefits of the THA's distortion effect. Simply turning up the input gain and engaging the 20 dB boost to capture a quiet sound source yielded quite a bit of noise, so I preferred to use the 20 dB boost for its recommended overdrive function.

LOW-PRESSURE SYSTEM

Surprisingly, the Tampa seemed to increase the low-end and midrange sustain on certain sound sources, such as toms, acoustic guitar, and the dum of a dumbek, which added greatly to the character of each. The result was a reverblike blossoming effect, which I suspect is the THA circuit enhancing the decay of the lower frequencies. However, M-Audio suggested that the Tampa is merely revealing the individual characteristics of the microphones. None of the other preamps exhibited this behavior.

While the preamp enhanced the dum on a dumbek, it also altered the mid-frequencies, turning the bek into a bawk, which sounded great. Female vocals recorded with an AKG C 3000 B through the Tampa sounded warm and detailed. In addition, the Tampa brought out some of the high harmonic content of a classical guitar track, which the other preamps did not. This added depth to the sound of the instrument.

The Tampa exhibited more character than the understated RNP8380 and the Mackie 1202-VLZ. Compared to the Grace 101, the Tampa wasn't quite as detailed and clear in the high end, and the transients sounded somewhat compressed dynamically. The Tampa sounded closer to the Peavey VMP2 tube pre, but it wasn't quite as defined and crisp and was less dynamic. The Universal Audio 2-610 sounded drier and clearer in comparison with the Tampa's fat, wet sound. The Tampa's A/D converter held its own against the Digi 001's converter.

I also put the Tampa through some loudspeaker tests at Myles Boisen's Guerrilla Recording studio, and the results were revealing. Placing a Neumann KM 184 two feet in front of a single speaker, with baffling behind the mic to absorb reflections, we played several tracks of vocal pop and instrumental music through the system. In some instances, the Tampa's blossoming effect muddied up the mix. In addition, it diminished the airiness of a female vocal part slightly and reduced the punch of a kick drum. Overall, however, the Tampa sounded good.

THE SQUEEZE

The Tampa's dual optical-servo compressor is one of its major assets. Compared with the Langevin Dual Vocal Combo (which is one of my favorites for transparent optical limiting and preamp warmth), the Tampa performed well, although it didn't sound quite as smooth. The Tampa wasn't particularly transparent in radical compression situations, but it maintained clarity and didn't have the woolly sound you might expect.

Although it's not an application that's mentioned in the manual, I also used the Tampa as a standalone compressor to fatten up a vocal in a mix by giving it an overdriven, tubelike sound. The results were pleasing.

For my tastes, the Tampa's maximum attack time of 10 milliseconds is on the fast side, and 250 milliseconds as a minimum release time is a bit slow. In addition, the lack of makeup gain in the compressor was inconvenient. However, the Tampa's compressor is a useful feature that sounds great overall.

VISITORS WELCOME

The Tampa is a versatile preamp with a host of features you don't usually find on preamps in its price range. It has plenty of character, with a decent amount of clarity in the high end and a fat-sounding midrange and low end that sets it apart from other preamps. In addition, the THA feature is effective for adding tubelike characteristics. If you're looking to enhance your project studio with a quality preamp that has dynamics processing and digital converters, the Tampa is worth a visit.

Tampa Specifications
Analog Input	(1) balanced/unbalanced ¼" TRS/XLR Neutrik combo connector
Analog Outputs	(1) balanced/unbalanced ¼" TRS; (1) XLR
Digital Outputs	(1) S/PDIF; (1) AES/EBU
Input Impedance Settings	300ž, 600ž, 1.2 kž, or 2.4 kž
Sampling Rates	44.1, 48, 88.2, and 96 kHz
Word Length	24-bit
Gain Range	34 dB (12 dB-46 dB with +20 dB switch off)
Output Impedance	600ž
Frequency Response	20 Hz-40 kHz (±0.25 dB)
Signal-to-Noise	110 dBA
Power Consumption	12 VAC
Dimensions	2U × 5.5" (D)
Weight	5 lb.
Compressor
Gain Reduction	20 dB minimum
Threshold	-20 dBu to +20 dBu
Compression Ratio	1.1:1 to 10:1
Attack Time	1 ms-10 ms
Release Time	250 ms-5 seconds

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Karen Stackpole operates Stray Dog Recording Services and is Director of Studio Maintenance at Ex'pression Center for New Media. Thanks to Myles Boisen and Steve Orlando.