Neve's venerable 1073 preamp and equaliser are both now available in API's popular 'Lunchbox' format. Were they worth waiting for?
The Neve 1073 channel module, designed back in the early 1970s, is probably the most revered and most copied preamp design on the planet, with countless replicas, 'homages' and repackaged versions to choose from. Its popularity is not lost on the current AMS Neve company, of course, and the same core design is still manufactured in four different formats, including the retrofit 1073 preamp/equaliser module, the 1073 DPD and 1073 DPA rackmount dual preamp, and the subject of this review — the new 1073LB version, intended for use in a 500-series 'Lunchbox' chassis, which provides the housing, power supply and I/O connectivity.
If you've ever seen inside an original 1073 channel module, you'll know that squeezing all that circuitry and the large transformers and inductors into an API 500-series Lunchbox module format just isn't physically possible. Consequently, AMS Neve has split the 1073's preamp and EQ sections into two separate but related Lunchbox modules. The 1073LB is the preamp proper, accommodating the transformer input and output stages into one unit, while the 1073LB EQ contains the separated equaliser section. These two Lunchbox modules are designed to be used together via a bespoke 'insert mode' configuration, which recreates the original signal path from the preamp's input stage, through the EQ and back to the preamp's output stage. Alternatively, each unit can be used entirely independently, and to that end the EQ module is equipped with its own electronically balanced I/O stages. I'll discuss the EQ section more in a moment, but first let's look more closely at the 1073LB.
This module is based very closely indeed on the original 1073 microphone preamplifier design, using exactly the same architecture, the same class-A circuitry, and even the same hand-wound input and output transformers. However, the method of construction is obviously very different, simply in order to fit everything into the constrictive Lunchbox module format. For example, the original expensive and bulky multi-level gain switch has been replaced with a simpler one controlling relays to provide the functions instead. Some might argue that this re-engineering has an audible effect on the sound character that was undoubtedly influenced in part by the hand-wired looms and plug-in amplifier circuit board arrangements of the original units. While this may be true in a strict A-B comparison, it wasn't something that I noticed or was concerned about. To my ears, the character that shouts '1073' is still there, loud and clear!
The original module's rotary gain control and output polarity inversion button have been retained in their original form, and have been supplemented with a front-panel microphone input impedance button (this facility was always present in original 1073 modules, but required the appropriate chassis connector wiring). Another divergence from the original design is the addition of a useful +5/-10dB rotary Trim control. This serves much like the fader of a console-mounted unit and is a facility that has proven very useful in the 1073DPA and DPD rackmount versions. To assist in optimising signal levels, AMS Neve have also fitted a 'signal presence' LED (green above -25dBu and red over +26dBu), and another push-button selects the front panel 'combi' XLR input connector instead of the Lunchbox's chassis' rear-panel input. Thanks to the transformers, both mic and line inputs, and the line output, are all fully balanced and floating (earth free), and phantom power is automatically disabled when the gain control is rotated to a line-input position. Phantom power is available when the gain switch is at any of the microphone settings, toggled on and off by pressing the Trim control.
As anyone familiar with the original 1073 will know, the rotary gain switch is more complicated than most, but the same functionality has been retained on the 1073LB. The microphone side of the switch is calibrated in input signal levels from -80 to -20dB, in 14 steps of roughly 5dB, with an 'off' position between the 50 and 55 dB marks. The review model measured 79dB with the Trim at its centre detent position, and an astonishing 84dB with the Trim control fully clockwise. The minimum gain in microphone mode measured 18dB, and the 'off' position provided just 7dB of gain.
Moving around to the line-input side of the rotary switch, which is separated from the mic side with another 'off' position, the scale is again marked with input signal levels from -20 to +10dB, again switching in 5dB increments. The input impedances are relatively low for all inputs, being just 4kΩ for the line input and either 1200Ω or 300Ω for the mic input, depending on the front-panel switch setting. There is no dedicated instrument input facility.
A two-way DIP switch on the rear panel provides an alternative module-earthing mode (necessary to enable phantom power in some non-API Lunchbox chassis designs), and to enable the 'insert mode' when integrating a 1073LB with a 1073LB EQ module. When the insert mode is enabled, the audio signal from the 1073LB's input stage is routed via a socket on the module's rear panel, through a supplied link cable to the EQ module, and then returned via the same cable to the preamp module's output stage. This same insert facility will be compatible with other modules, including the 2264 ALB compressor, announced shortly before we went to press.
Despite its diminutive size, the 1073LB packs the full punch — both sonically and electronically — of the original 1073 module, and in use the 1073LB did all that was expected of it. There is no doubting the pedigree in its distinctive sound character and the slightly quirky operational controls. The control knobs and buttons match the original styling very closely and work in exactly the same way. However, I was a little frustrated by the method used to enable phantom power: in reaching for and rotating this control, I often found I inadvertently toggled the phantom power supply off or on, with all the attendant bangs and thumps! Clearly, space for switches is severely restricted, but perhaps a more benign function should have been allocated to the Trim switch, such as the output polarity inversion?
As you'd expect, the module's test measurements are all very good, with distortion coming out well below 0.07 percent, even when driving the output to +20dBu. The dominant distortion character is almost equal amounts of second and third harmonic, with the latter being slightly greater. The frequency response is easily within ±0.5dB between 20Hz and 20kHz, falling to -3dB at about 8Hz and 40kHz when working at full gain. At low gain settings there is a very subtle LF bloom, and at high gain settings the extreme HF is very slightly subdued. Whatever the gain setting, the preamp always delivered a full and rich bottom end, a detailed and present mid-range, and a smooth, silky sheen at the top end. Plenty of modern preamps are quieter, but I never found input noise to be an issue, even at high gain settings.
The 1073LB EQ is the partnering four-band equaliser for the 1073 preamp module, and is designed to fit a single Lunchbox module width. As shipped from the factory, the equaliser module is configured as a stand-alone unit, with its I/O accessed through the Lunchbox chassis connectors in the usual way. However, it can also be user-configured to operate as an insert within the signal path of a 1073LB module, so that a conventional 1073 module audio path is properly replicated, and this configuration is called the 'insert mode' (see below).
The 1073LB EQ replicates exactly the same EQ functionality as the 1970s original 1073 module, with a fixed-frequency high-shelf section, adjustable-frequency mid and LF sections, and an adjustable high-pass filter. In stand-alone mode, the line input and output stages are modern, electronically balanced affairs, which allow the pure character of the inductor-based equaliser circuitry to shine through without the subtle transformer-thickened veiling that is inherent in a conventional 1073 channel module. To help minimise any problems associated with stray magnetic fields from other modules or the Lunchbox power supply affecting the EQ's inductors, the 1073LB EQ is protected in a mu-metal case.
As with the original console module, the EQ section is equipped with a global on-off button, although the low-shelf, mid-band and high-pass sections all have their own independent 'off' modes too. To assist with level management, an LED provides an indication of signal amplitude, illuminating green above -25dBu and red above +24dBu.
The LF-shelf section is operated with the traditional dual-concentric rotary control comprising a continuous boost/cut level knob mounted above a rotary switch to set the turnover frequency. The gain range is ±16dB, with turnover frequencies of 35, 60, 110 and 220 Hz, and Off — all the same as the original. The mid-range bell section also employs a dual-concentric control, providing a slightly wider gain range (±18dB) and centre frequencies of 0.36, 0.7, 1.6, 3.2, 4.8 and 7.2 kHz, and Off. Again, these are exactly the same options as the original.
However, in a slightly confusing departure from the original design, the high-shelf section is also provided with a dual-concentric control. In this arrangement, the upper knob provides up to 16dB of boost or cut with a fixed 12kHz turnover — the same as the original fixed HF shelf — while the lower rotary switch section is used to control the high-pass filter turnover frequency. The 18dB/octave high-pass filter frequency options are the same as the original 1073, of course, offering 50, 80, 160 and 300 Hz, and Off.
This non-standard arrangement is a little confusing for anyone who is familiar with traditional Neve modules — not least because it looks very similar to the later 1084 module arrangement, which introduced switchable HF-shelf turnover frequencies. Of course, the reason for this variation of control format is simply because the size of the Lunchbox module precludes the original arrangement. While possibly offending Neve purists, I have to say that this configuration is quickly assimilated and certainly works well enough in practice.
My bench tests revealed that the EQ module performed precisely as specified, achieving a signal-to-noise ratio of 105dB (with a +20dBu input) and a THD+N figure of an impressive 0.002 percent. There is a mild tendency towards third-harmonic distortion when the input level is pushed hard, but the tonality is otherwise very neutral. The EQ curves produce text-book plots, with well-proven and musical results.
Conversion to insert-mode operation involves changing a rear-panel DIP-switch setting, just as on the preamp module, and connecting the supplied link cable between the bespoke sockets just below the main edge connectors on each module. The cable can be arranged to sit neatly under the Lunchbox backplane circuit board in most cases. When configured for insert-mode operation, the EQ module's Lunchbox chassis input XLR becomes redundant, but the corresponding output connector still carries the EQ'ed output signal via the electronically balanced output stage. The processed signal is also available via the preamp module's output XLR, of course, and comes via the preamp's transformer output stage. It's interesting to compare directly the quality of the EQ section with and without the coloration associated with the preamp's transformer I/O stages, simply by swapping the output cable between the preamp and EQ module output XLRs.
The Lunchbox provides a very popular means of allowing users to build up a varied collection of signal processors in a cost-effective and manageable way. Third party replicas of and homages to the 1073 have been available for some time, but to have an official product built to the original technical standards, and especially one which can be used so flexibly, with the original EQ design intact, holds a very strong appeal indeed. It's all good, and I want some...
There are plenty of high-end 'character' preamps and EQs around these days, and that applies as much to the API Lunchbox format as to the more traditional 19-inch rack units. API themselves, for example, offer both preamps and EQs, and there are many boutique manufacturers offering a different take on the general 'character' theme. For a distinctly 1073-like character, though, there are a few Neve imitators around. Sound Skulptor, for example, offer the MP573 preamp and EQ573 EQ — and if you're looking to save money, these can be bought as DIY kits. Rupert Neve Designs offer the RND517 preamp, which is a more recent design by Rupert Neve, but at the time of going to press they didn't have a 500-series EQ available. There are also plenty of non-500-series designs around, from Neve themselves, and various others such as Brent Averill Engineering.