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Roger Mayer 500 Series: 68MP, 58LM, 456HD

Modular Channel Strip By Neil Rogers
Published November 2020

Roger Mayer 500 SeriesPhoto: Neil Rogers

Mayer’s all‑analogue tape emulation is joined in the 500 series by a mic preamp and limiter.

Roger Mayer is perhaps best known in the UK for designing and building guitar pedals for some of the legendary names of the ’60s: Jimi Hendrix, Jeff Beck and Jimmy Page, for example. But across the pond, where he moved in the late ’60s, he’s just as well known for a range of outboard gear that graced many studios, including Electric Lady in New York. Today, Roger is based in his native UK, where he continues to make high‑quality pedals and studio processors, and I mean ‘make’ literally: the units are hand built by Roger himself.

My interest in his recent designs was first piqued when producer Dave Eringa (Roger Daltry, the Manic Street Preachers) spoke almost evangelically about how much they’d transformed his approach to recording and mixing. And having tried, loved and then bought a couple of the 456HD 500‑series tape‑machine emulation modules, I decided to check out the two newer 500‑series units in Mayer’s range: the 68MP mic preamp and the 58LM limiter. Together, these three modules have the potential to form an interesting recording channel.

Beauty In Simplicity

All three units sport the same styling as Roger’s outboard offerings, with simple, brushed‑steel metalwork adorned with a glossy white background for the clear and colourful control markings. The controls feel solid and functional, and while the appearance is not displeasing, the main focus is clearly on what’s happening under the hood.

They’re all derived from standalone devices in the Roger Mayer range, so I made a point of speaking with producer/engineer Sean Genocky, who has been deeply involved in the development of these modules, to find out more of the thinking behind them. Sean explained how keen they were to make some of Roger’s designs more affordable, which these modules do even when you factor in the 500‑series chassis: they’re each available for £600$650 or under, whereas Mayer’s full‑sized rackmount devices (some of which, admittedly, have several channels) can cost five or six times that. But he was also keen to discuss workflow, and referenced an era when recording and mixing was a simpler experience: recording an artist who knows what they’re doing through a high‑quality recording chain really shouldn’t be an overly complicated process. Hence the focus is not only on delivering the sound of the larger units, but also on keeping the controls fairly minimal and simple to use.

The 68MP

It’s sometimes hard to find interesting things to say about mic preamps, but Mayer’s 68MP is an exception. Like his other modules, this one runs on internal 48V rails, stepped up from the standard 32V 500‑series supply for greater headroom. Unusually for a modern design, 48V phantom power is always available; there’s no on/off switch. Roger explained to me that by using an input transformer rather than the [electronically balanced] op‑amp approach, the 68MP can safely provide phantom power without the engineer having to engage it; it’s how all of his console designs operated ‘back in the day’ at Olympic and Electric Lady studios, and he considers it to be perfectly safe. There’s a body of opinion that disagrees with him on that point, but I experienced no issues when hot‑swapping a variety of mics during the review period, and if it does bother you there’s always the option of turning the 500‑series host chassis off when changing mics.

The 68MP: a quirky, but great‑sounding mic preamp.The 68MP: a quirky, but great‑sounding mic preamp.Photo: Neil RogersAnother point of interest is Mayer’s approach to metering. The 68MP uses a simple three‑LED meter system that gives a very broad but surprisingly helpful guide to what are sensible operating levels. The meter displays the signal peak level but employs a concept known as hysteresis in the detector circuit so that the LED remains lit for a while as the signal decays. Thus, rather than the meter dancing around and distracting you, you see a more gradual, smoothed movement. When in a busy session, that’s helpful: you can glance at your preamp and swiftly get an idea of whether you’re in the right ballpark. If two LEDs are lit, you’re good; if only one is active you can add a bit more gain; and if three are lit then you should consider backing things off a bit. As all my 500‑series units are set off to one side of my listening position, this worked really well for me while recording; I found setting a healthy level quick and intuitive.

These two more unusual features aside, you can find all the usual controls you’d expect on a mic preamp, including a polarity inverter, a ‑20dB pad and a high‑pass filter. The filter is set by default with a 12dB/octave slope at 120Hz, but if you prefer a less or more assertive setting that can be specified when purchasing.

In use, the 68MP sounded excellent. It always gave me confidence that it was helping whatever mic I was using to capture the full range of a signal. It isn’t what I’d describe as a ‘character’ preamp; other Mayer devices are intended to cover that side of things later in the chain. But neither is it entirely neutral. Frequent comparison with my Neve 1073LB, a familiar point of reference, revealed that the 68MP has a cleaner, brighter sound, yet it also delivers a pleasingly full‑sounding bottom end on sources such as kick and bass. It became a particular favourite on acoustic guitar, a source for which I find some preamps seem to convey too much low‑mid ‘mud’, and more generally I found it usually helped me to capture as much detail as I needed on many different sources. In short, it sounds good and is quick and easy to use. I have no complaints.

58LM Limiter

In Bob Thomas’s review of Mayer’s RM58 limiter in 2019 ( he offered an excellent, detailed explanation of the ‘feedforward’‑style design that Roger has developed over a number of years. Physically, the 58LM bears little resemblance to the full‑size RM58, of course: the lack of panel space in the 500‑series format led Roger Mayer to give it fewer controls (fewer than most dynamics processors, in fact). But similar circuitry is employed inside and it shares many of the RM58’s characteristics.

The 58LM is based on the feedforward circuitry used in Roger Mayer’s highly respected RM58 stereo limiter.The 58LM is based on the feedforward circuitry used in Roger Mayer’s highly respected RM58 stereo limiter.Photo: Neil RogersFirst up is a Wave knob. This allows you to control the nature of the harmonics that are generated when the limiter is acting. This is followed by a threshold control labelled Drive; you turn the control ‘up’ for more gain reduction. The last two controls are an output level knob and a Mode switch. The latter toggles between two different attack and release profiles. These two default options (medium attack/slow release, and slow attack/fast release) are well judged, and seem to me to cater very well for most sources.

There are many more options on the full‑sized RM58 but accommodating them on the front panel in this format was impractical, so instead you can use jumpers on the inside to access a further six attack and release times, giving you up to 36 potential combinations in total. If this sounds a faff, it’s worth noting that you shouldn’t find yourself needing to use the jumpers often. As I say, the defaults work well, and the idea really is that if you wanted to dedicate a 58LM to a particular source (a bass or snare recording channel, say), you could tailor the specific module accordingly.

I initially found the 58LM to be a curious beast, since it wasn’t immediately apparent what control was doing what. Usually, these things are reasonably easy to discern by ear, but since there’s no metering and this feedforward style of compression can sound so incredibly transparent, that was harder work here. Consequently, I found it rather difficult to use during early tracking sessions: I could hear that it was making a bass guitar feel firmer and more solid, for example, but on more transient‑heavy material, it never really sounded ‘squashed’, which took some getting used to.

It was in the more controlled surrounding of a mixing session where I really got the chance to get a good feel for what it can do — it was very impressive. I was able to reduce the dynamic range of a snare drum with ease, without losing any of its sense of attack or ‘punch’. The same was true when I used the 58LM to process a picked acoustic guitar track, and it worked superbly on an electric guitar rhythm part. In general, I liked it a little less on lead vocals, where I’m often seeking more of a ‘compressed’ sound. However, I found that I could use it to make a vocal more dynamically consistent and I was able to dial in a bit more aggression in a vocal by playing with the ‘wave’ control.

After getting to know the 58LM a little better, I realised that my initial nervousness when using it during tracking had been unfounded. Actually, it’s really quite hard to mess things up or make it sound bad. Partly that’s because there are so few controls; once you have your head around how it works, you just have to use your ears to get the best from it.

I now use the 456HD on pretty much everything I record.


The 456 tape emulation circuitry is Mayer’s secret sauce, and it has made its way into several products now. It first emerged as a guitar pedal, but was soon updated to create a standalone half‑rack stereo device (which Matt Houghton reviewed back in 2014: The same circuitry has now found its way into a number of rackmount devices, including some multichannel mic preamps and the aforementioned RM58 stereo limiter.

The 456HD aims to recreate the sound of a perfectly aligned Studer open‑reel tape machine with Ampex 456 tape, but without the noise, wow and flutter.The 456HD aims to recreate the sound of a perfectly aligned Studer open‑reel tape machine with Ampex 456 tape, but without the noise, wow and flutter.Photo: Neil RogersThe design aim was to recreate the sound of a perfectly lined‑up Studer A80 with Ampex 456 Tape, and while I don’t know how authentic an emulation it is (I haven’t had the chance to make a direct comparison), I can say with confidence that it sounds different from any other hardware or software processor I’ve used. I’ve owned a pair of the 456HD modules for a few months now, so have a little more experience with these than the other modules sent for review, and I have to say that they’re seriously addictive. In fact, I now use them on pretty much everything I record, and have even used them on the mix bus for a couple of projects.

You can drive them hard to achieve saturation if you want to, but they’re not really intended to sound lo‑fi or too obviously ‘tapey’ in the way some plug‑in tape emulators can. They do a wonderful job of shaping a source, so that it seems to require less by way of other processing, and that’s especially the case with bright sounds such as cymbals or particularly bright vocals. They help somehow, subtly, to control the dynamics of a source whilst also delivering that tape‑like head bump and rounding off the very top end in a pleasant way. The bias control is handy for fine‑tuning: I tend to use it rather as I might a tilt EQ, to achieve a brighter or darker result. As I’ve got more used to the 456HDs, I’m increasingly using them while tracking, largely because the cumulative effect of processing various individual sources through them at that stage is that I seem to require fewer plug‑ins at mixdown!


In short, then, the preamp sounds excellent and while the limiter may not be the best choice for a novice, it is good and offers something nothing else in my studio can. The 456HD provides many of the better qualities of recording to analogue tape, without the unwanted noise, wow and flutter; it always seems to make things sound better. But the combination of the limiter and 456HD is particularly delicious. Put all three together and you have a superb recording front end for any DAW. Indeed, the project on which I used only these three modules as a recording channel needed very little additional processing in the mix. They’re all more than worthy of your attention.


There are plenty of 500‑series mic preamps to choose from but fewer feedforward limiters; the API 527, which is switchable between feedforward and feedback operation, is perhaps the best‑known example. There are vanishingly few tape emulators in this format, the obvious competitor being Rupert Neve Designs’ Portico 542. Sound Skulptor’s more affordable TS500 Tape Simulator is also worth checking out. Of course, a number of saturators, such as Looptrotter’s Emperor 500, Elysia’s stereo Karakter 500 and Bereich 03 Audio’s Density, might sound different but could perform an equivalent function in the signal chain.


  • Good pricing.
  • Great‑sounding preamp with clever and useful metering.
  • 58LM limiter is very transparent.
  • 456HD processing really does make digital recording easier.
  • The three units combine to make a great channel strip.
  • Simple controls encourage you to use your ears.


  • The learning curve for the 58LM could put some off.
  • Unusual approach to phantom power.


Roger Mayer has successfully brought his studio preamp and limiter designs into the 500‑series format. With the excellent 456HD tape emulation, these form a high‑quality channel strip that can both help shape your recordings and encourage you to stray out of the box when mixing.


68MP £600. 58LM £570. 456HD £480. Prices include VAT.

68MP £500 (about $645). 58LM £475 (about $608). 456HD £400 (about $512).