Prism MMA-4XR

4 Channel Mic Pre Amp

Prism MMA-4XR 4 Channel Mic Pre Amp

Review by George Shilling

This four channel mic preamp is part of the Maselec Master Series, an all-analogue unit designed by Swedish audio wizard Leif Masses. He started out at Abba’s Polar Studios in Sweden, but moved on to engineer records a number of major rock acts such as Led Zeppelin, Black Sabbath, and Jeff Beck, with whom he collaborated for many years, most notably on the Grammy-winning Jeff Beck’s Guitar Shop album. In the 1980s he achieved notoriety for designing a replacement circuit for SSL 4000 series EQs. Intended to possess some of the characteristics of Pultec EQ, it was christened Maselec, and this name has stuck for Masses’ designs, some of which are now marketed and packaged by Prism Audio in the UK. He also has his own company which is best known for its mastering consoles, he has recently been working on a multi-band compressor, and this year undertook a huge install of a custom archiving system for the Library Of Congress National Archives in the USA.

In the late 1990s Masses forged an alliance with Prism to market his stereo mastering compressor and stereo mastering EQ. These sell increasingly well, and are achieving something of a cult status. The original MMA-4 dates from a similar time, and the updated XR version brings a number of changes. Cosmetically, the front panel now matches the super-high-end ADA-8XR converter; this design is a deliberate attempt to indicate that they are perfect partners, mic preamps to match the high quality of the converters.

Prism MMA-4XR 4 Channel Mic Pre Amp

Internally, the circuitry has undergone almost a ground-up redesign, with only the PSU section and layout remaining similar. The topology remains the same, but over the years Masses’ admits to gaining knowledge, and he realised that he could improve on the design. The XR provides a maximum gain of 69dB as against the old model’s 60dB. This improvement was driven by the increasing popularity of ribbon microphones, but to achieve the extra 9dB Masses asserts that he needed three times the bandwidth, due to the bandwidth drop with higher gain. To this end, the front-end is a new discrete design with 10 transistors.

The MMA-4XR is indeed as well-built as the ADA-8XR, with the chunky curved front panel, and even some similarly reassuring relay clicks when powered up. Operation couldn’t be much simpler. Each of the four channels is mirrored on the reverse with an XLR microphone input and line output. The gain is switched in 9dB steps, and each channel provides phantom power, phase reverse and mute toggle switches, along with basic metering. Indeed the gain is clean and powerful, and the only function I missed was any kind of fine gain adjustment.

Prism MMA-4XR 4 Channel Mic Pre Amp

There is no (currently fashionable) adjustment for impedance. But there was no need, it sounded impeccable with any type of mic I could think of, revealing enormous detail. The preamps are extremely quiet, and if you want to hear the sound and character of a microphone, this seems about the best way to achieve that. Sometimes this starkness can seem a little dry, but there has been something of a trend of late towards natural-sounding recordings – if nothing else, one must have a pure signal in order to make use of all those crunchy virtual tape and console plugins! Masses is even slightly disparaging of “characterful” models, gently implying that such descriptions are an excuse for poor design…!

The price compares favourably with other high-end units, so if you simply want clean gain you should like this a lot.

Pros: Ultra-clean; Plenty of gain; Useful Mute switches
Cons: No fine-adjust of level or gain fader; Nothing ‘characterful’ about it!

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