PRODUCT DESCRIPTION

No matter how much you spend on a microphone, its ultimate performance depends on how it interacts with the preamp it's plugged into. Many high-end mic preamps can effortlessly amplify the slightest sonic nuance, creating an aural panorama that's breathtakingly realistic, excitingly vivid, and truly 3-dimensional in scope. For years they've provided fidelity that just hasn't been possible with the "stock" mic preamps built into mixing consoles. Until now.

To develop the new XDR™ (eXtended Dynamic Range) mic preamp, the engineering team started with blank paper, concerned only with matching or exceeding the performance of $500 to $2000-per-channel esoteric preamps. They went through hundreds of iterations and revs and spent countless hours subjectively listening (and arguing). They started all over again several times. They scoured the world for rare parts. Then they spent more time critically listening and evaluating the design with every high-end microphone you can think of. Then they brought in veteran recording and live sound engineers for more exhaustive listening tests.

What they ultimately ended up with is not just an awesome sounding design. XDR is also a) highly resistant to damage caused by "hot patching" (caused by routing a phantom powered mic through a patch bay); b) remarkably independent of cable-induced impedance variations; and c) able to reject extremely high RF levels without compromising high frequency response.

Because a mic preamp must amplify faint one millivolt input signals up to a thousand-fold (60dB), its rectification components can also pick up radio frequency interference (RFI) from AM and FM stations, cell phones, and pager transmitters — even microwave ovens — and amplify them to audible levels.

Mackie assaulted RFI on 3 fronts. First, they incorporate bifilar wound DC pulse transformers with high permeability cores that reject RFI but don't attenuate the sound at 15kHz and above. Second, they use carefully matched, high-precision components for critical areas of the XDR preamplifier. Third, they direct-coupled the circuit from input to output and used pole-zero cancellation constant current biasing (which also avoids increased intermodulation distortion at high common mode signal levels).

Bottom line for the non-technical: you can use the new XDR mic preamps at the end of extremely-long cheap mic cables in an RFI-saturated urban environment while talking on your cell phone...without hearing a trace of RFI.

If a mic preamp isn't designed right, it will actually sound different depending on the impedance of the microphone and the cable load! XDR's Controlled Interface Input Impedance system accepts an enormous range of impedances without compromising frequency response.

0.0007% Total Harmonic Distortion. The lowest ever in any compact mixer.

Flat response. Not only are XDR mic preamps flat within a tenth of a dB across the bandwidth of any known microphone, but are also only 3dB down at an astonishing 192kHz!

Super-low intermodulation distortion at very high operating levels thanks to instrumentation-style balanced differential architecture, linear biasing, and use of DC-coupled pole-zero-cancellation constant current that frees the mic preamp from power supply fluctuations.

Think of the 1604 as an ultra-premium, esoteric mic preamp... that just happen to have really excellent compact mixers attached.

Features
Ultra-low noise, highest headroom in its class

16 new precision-engineered XDR™ Extended Dynamic Range premium studio-grade mic preamps with: Ultra-wide 0-60dB gain range, 130dB dynamic range for 24-bit, 192kHz sampling rate inputs, +22dBu line input handling, distortion under 0.0007% (20Hz-20kHz)

Advanced DC pulse transformer RF rejection

4 subgroups with left and right assigns and direct outs

16 line inputs, 16 channel inserts

60mm long-wearing logarithmic-taper faders

Constant-loudness pan controls

Switchable AFL/PFL Solo

6 aux sends per channel with 15dB gain above Unity

Aux 1 and 2 pre/post

Aux Send 1-2 Master section with level controls, Solo switches, and Solo LEDs

Level, pan; -20, Solo and OL LEDs on each channel

RUDE solo light doubles as a mini-tanning booth

4 stereo aux returns, 8 direct outs

3-band active EQ with sweepable midrange

18dB/oct. 75Hz Lo Cut filter on each channel

Control Room/Phones outputs with multi-input source matrix

RCA tape inputs and outputs

Tape input level control and Tape To Main Mix switch

Balanced 1/4 in. inputs and outputs (except inserts)

Switchable phantom power for condenser mics

5 physical configurations via rotating I/O pod

Rugged steel main chassis, sealed rotary controls

Built-in power supply, rack mount kit included

TECHNICAL DESCRIPTION

Main Mix Noise
20Hz-20kHz bandwidth, 1/4 in. Main Out, channel Trims @ unity gain, channel EQs flat, all channels assigned to Main Mix, odd channels panned left, even channels panned right

Main Mix faders down, channel faders down: -100dBu

Main Mix fader unity, channel faders down: (90dB Signal to Noise Ratio, ref +4dBu) -86.5dBu

Main Mix fader @ unity, channel faders @ unity: -84.0dBu

Total Harmonic Distortion (THD)
1kHz @ +14dBu: 20Hz-20kHz

Mic in to Main out: below 0.0007%

Attenuation (Crosstalk)
1kHz relative to 0dBu, 20Hz-20kHz bandwidth, Line in, 1/4" Main Out, Trim @ unity

Channel Mute switch engaged: -84dBu

Channel fader down: -84dBu

Frequency Response
Mic input to any output

20Hz to 60kHz: +0dB/-1dB

10Hz to 100kHz: +0dB/-3dB

Equivalent Input Noise (EIN)
Mic in to insert Send out, max gain

150 ohm termination: -129.5dBm unweighted

Common Mode Rejection (CMR)
Mic in to insert Send out, max gain

1kHz: better than 90dB

Maximum Levels
Mic In: +22dBu

All other inputs: +22dBu

Main Mix 1/4 in. TRS outputs: +28dBu

All other outputs: +22dBu

Impedances
Mic In: 1.3 kilohms

Channel Insert return: 2.5 kilohms

All other inputs: 10 kilohms or greater

Tape out: 1.1 kilohms

All other outputs: 120 ohms

EQ
High Shelving: ±15db @ 12kHz

Mid Peaking: ±15dB, sweep 100Hz-8kHz

Low Shelving: ±15db @ 80Hz

Low Cut Filter: 18dB/octave, -3dB @ 75Hz

Power Consumption
120VA.C., 50/60Hz, 50 watts

Fuse Ratings
120V: 1A Slo Blo, 5 x 20mm

220-240V: 0.5A Slo Blo, 5 x 20mm

Weight
20 lbs. (9.1 kg)