Line Magnetic LM-512 CA preamp/LM-845 Premium integrated/power amp

The LM-845 Premium is a real gas guzzler of an amplifier built on two chassis, with the main one alone weighing 40 kilos and the ‘smaller’ unit coming it at over 20kg. The latter houses the output transformers, which gives you an idea of the manufacturer’s ambitions and how little the company is prepared to compromise. As you might be able to tell from the array of controls on the front panel, the LM-845 operates as both an integrated amplifier or as a power amp, and there are four line inputs (one on XLR) plus a preamplifier input and a control to choose between operational modes. There’s even a remote handset for volume. The array of knobs and meters on the front would suggest that it’s a measurement device for good reason as it can also measure the bias on the various tubes sprouting from the top.

There is also the option to adjust negative feedback between minimum and maximum. I listened in its full-on mode because that was how it arrived and would lend itself to less sensitive speakers than are generally chosen for 30 Watt amplifiers. However, I gave the minimum feedback option a try and got a more ethereal and soft sound that worked well with classical pieces but less so in situations where rhythm is crucial. The tube array consists of 12AX7 triodes in the input stage, pairs of 310A and 300B drivers, and the eponymous 845 triodes in single-ended mode, providing the loudspeakers’ power. The latter usually looks pretty significant, but on an amplifier of this scale, they don’t seem extreme in the least.The output transformers in the second, Premium, chassis connect to the amp with a pair of chunky umbilical cables, and speaker cabling connects to one of three impedance taps (4, 8 and 16 Ohms) on the back of this unit. Fit and finish are once again excellent, but the styling is more restrained than the main amplifier.

Listening commenced with the 845 Premium as an integrated driving Bowers & Wilkins 802 loudspeakers that are strong on sensitivity if not easy to drive. Still, the pairing worked well, unusually so for a single-ended triode. The critical tube quality of tonal colour was immediately apparent on Arve Henriksen’s trumpet and the atmospheric electronica that surrounds it. There was good depth to the soundstage too, and not too much midrange forwardness. The latter is all too common with SETs when they struggle with a heavy load, but there wasn’t much struggling going on here. I loved the depth of tone it pulled out of the basses on ‘Magnet Pulls Through’ [Tortoise, Thrill Jockey], and the weight behind the kick drum was round and deep. When the snare comes in, you can feel its snap and the pulse of the soundfield produced by the bass, which is tactile music reproduction with lots of nuances. Immediacy is a classic triode characteristic, one of the reasons for this ancient technology’s appeal, and you get plenty of it with the Line Magnetic, which brings Leonard Cohen and Herbie Hancock’s version of ‘The Jungle Line’ to life [River: The Joni Letters, Verve]. The amplifier enhances the gravelly-voiced description of Rousseau’s painting, making the imagery that much more vivid and lush.

Adding the LM-521 CA preamplifier to the system significantly enhanced all-round transparency; the low-level resolution was clearly increased, which meant that even simple pieces of music took on a far stronger sense of realism. One such being ‘Grandma’s Hands’ [Bill Withers, Just as I Am, Sussex], where the voice gains depth and shape as you might expect, but the rhythm section comes into full focus as well, now you can feel the groove as well as follow the tune. The preamplifier brings precision and definition of the quieter elements that, while it’s more revealing, is also beneficial to the musical flow. There often seems to be a trade-off between resolution and musicality, but this pairing brought a balance to these key qualities that were extremely rewarding. Allowing you to play jazz, classical, rock, you name it… and feel emotionally and intellectually involved with every piece.

Voices are a speciality, of course, each one offering up so much of its distinctive flavour when Van Morrison sings ‘Who was that Masked Man’ [Veedon Fleece, Warner Bros]in a falsetto, it strikes you to the core in a way that rarely happens. With more up to date recordings, the effect was equally provoking; the sheer presence of notes in the room giving the music a power to captivate that was inspiring. Out of interest, a pair of PMC twenty5.26i speakers were harnessed to this amplifier; these showed that the 845 Premium is no slouch when it comes to timing, letting the groove shine through on whatever was played.