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Review: BAE 73MPL 500-Series Mic Preamplifier

By Rob Tavaglione. All things considered, the Neve 1073 mic preamp/EQ module is likely the most popular mic amp in history.

All things considered, the Neve 1073 mic preamp/EQ module is likely the most popular mic amp in history. The reason, in a word, is saturation. There’s also St. Ives transformers at mic input and line input; a second amplifier circuit providing gain over 50 dB; a particularly sweet EQ with HPF circuit; and an output level control (not found on Neve original console modules, but useful for attenuating the hot output of a purposefully overdriven preamp stage) which all work together for a sound revered on vox, drums, basses and especially guitars. The result is big, dirty, crunchy rock guitars.

The industry’s love of 1073s spurred an enterprising Brent Averill to rack up 1073s and 1272s, which then led him to manufacturing his own clones. It must have been a really good idea. There now exists a cottage industry of classic Neve clones, actual AMS-Neve units slightly modernized, lower-budget Neve-like re-creations, plus Brent Averill Enterprises (now British Audio Engineering, led by Englishman Mark Loughman from a North Hollywood manufacturing facility) have their own 1073 (complete with EQ) as well as 1073 MP and DMP (rackmounted and tabletop, no EQ), among others.

[For more on BAE’s history and future, read Frank Wells’ recent interview with Loughman here: /article/view-from-the-top-the-student-becomes-the-master-mark-loughman-president-bae-audio/19532Ed.]

The 73MPL is BAE’s 500 Series 1073-type mic pre with no EQ. Design-wise it offers a challenge, since fitting that much circuitry into such a little space demands some compromise. BAE removed the line input transformer, retained the absolutely crucial mic and output transformers (the originals—the company has changed names to Carnhill), retained the critical level control and added a back-panel variable impedance (either 300 or 1,200 ohms) and thankfully provided a quarter-inch front-panel DI (see the “insides” photo below). Here’s the full rundown:

As luck would have it, I was called on for a thick and simple bass line the first day I got the 73MPL. The signal path I chose was vintage passive bass, front panel DI (which actually bypasses the input transformer), a little more gain than required (to harness that harmonically-enriched bottom end) and then a little attenuation and a little compression. Bam! My client loved the resulting tone–thick and not bright, clearly defined but not harsh. It’s a tone that sat easily in a folky mix. No problem.

I tried recording acoustic guitar and wasn’t immediately impressed. Don’t get me wrong—the sound was full, sweetly polite up top and natural. It’s just that I was aiming for something a little thinner, sparkly and cutting. A switch to a small diaphragm condenser helped the tone, but with 50 dB of gain there was some noise apparent.

Next session found me stacking electric guitars and the 73MPL stepped right up and could do no wrong. I didn’t even miss the EQ because it wasn’t needed. The tones were certainly deep enough and warm/thick enough. Its mids were focused without any obtrusion; its top was smooth, sexy and non-forward; and the subtle grit gave me requisite options. A suggestion: add gain excessively until just the right amount of extra “beard” appears and then dial back the output level until you’re safely below clipping on you A/D converters. If you don’t like this guitar sound, you’re probably wrong!

I tried the 73MPL on snare and really liked the response. The heft to the low-mids, the transient response and the saturation is all really very nice for rock. A quick check on toms and kick proved consistency. The only caveat is that users will need many channels of these to use them on a whole drum set.

I tried the 300 ohm setting with my AEA R92 passive ribbon and, sure enough, the lower impedance seemed to let the ribbon breathe with a more realistic sound and imaging, lower noise floor and better frequency balance. With most of my condensers I preferred the 1,200 ohm setting, but impedance variability is always a nice option to have, even if it’s rather inconveniently mounted on the back panel.

I came to learn that the 73MPL sounds nice on most everything and grabs tones that are thick and full, but it doesn’t need EQ. Here’s my proof: my Roland TR-8 drum machine tracked in mono via the 73MPL’s quarter-inch DI, passive bass DI’d too, acoustic guitar via a Blue Hummingbird SDC, tambo with a Blue Hummingbird and synth-pad (in mono) via the quarter-inch DI. This clip is raw with no compression, no EQ and not even an HPF—just pure 73MPL output, analog summed:

Without any actual 1073s, 1272s or clones on hand at my studio, I compared the 73MPL to my memory of those units and found it to be an ample competitor in today’s “sounds like a 1073” sweepstakes. I’d say the 73MPL is one of the darker/fuller 1073s I’ve heard, with slightly woolier low-mids and slightly-more-tame high-mids (they are the only manufacturer to use Carnhill at both input and output, after all). Maybe it’s not the ideal scenario for quiet string instruments or deep vocals (especially considering the noise floor at gains over 50 dB), but for basses, percussion, synths and electric guitars, the balance is spot on.

Considering the reasonable price of $899, the nearly-universal desire for project studios to acquire their first Neve (or at least their first Neve-like component), and the popularity of 500 Series racks in many big and small rooms, I expect the 73MPL to be a hit.


Just as this review went to press I received word that BAE had completed an update to the 73MPL’s design, an improvement that—you guessed it—addressed my only significant complaint: the relatively high noise floor above 50 dB of gain. I near-immediately received a production unit and closely compared it to the beta unit I still had in my possession.

Count me as cynical when it comes to 11th hour design changes, as such issues are my bane, but this improvement is well worth the effort. Currently, the 73MPL’s noise floor is dramatically reduced—whether using 300 or 1,200 ohms, quarter-inch DI or mic input, and especially when paired with passive ribbon mics; any noise is now lower in pitch, too. The difference at +70 dB is huge; it slowly tapers with each five dB step.

Please see the screen grab (below), which illustrates the difference proportionally:

The production unit captured the same rich and euphonic tone as the prototype review unit, as I re-tracked bass guitar, acoustic guitar and vocals with v2. I am satisfied with the changes and look forward to recording both loud and quiet sources with the 73MPL in the future, as I have purchased this production unit.

British Audio Engineering