The Line Magnetic 845i (3999/US$4895/3999) is an integrated amplifier with three line-level RCA inputs and a low-ish power output. Even to seasoned audiophiles, 22wpc into 8 Ohms wont sound like much. Thats because this Chinese-designed (and made) amplifier is a valve-based design where glowing glass bottles are deployed in its pre-amplifier and power amplifier stages. Also known as vacuum tubes, the valves ride on a single-ended Class A circuit. Digital capability? Nope. Phono stage? Nope. Headphone output? Nope. Heck, the 845i doesnt even have balanced inputs. Nothing about the 845i nods to the modern world. Weighing in at 35kg, its a million miles from modern-day Class D designs. Only a pre-amplifier input that recasts the 845i as a power amplifier differentiates it in spirit from amplifiers coming to market sixty years ago. That and a small metal remote for volume mute. Front the Line Magnetic with a streaming DAC (as I did) and you have a neat two-box system. With an amplifier thats arguably more future-proof than many modern counterparts, where built-in digital-to-analogue converters can sometimes see the unstinting march of digital quickly leave them behind. Back to those valves. Is their 22wpc enough to drive normal loudspeakers properly? And how does the Line Magnetic sound? Does it stick to the stereotypical view of valves buttery bass underpinning a sumptuous midrange and silky top end or does it tread its own path? Features operationThis Line Magnetic integrated uses seven valves in total, each one (or pair) having different characteristics suited to a particular job. The single 5AR4 is a two-element valve without a grid thats used for rectification, turning AC power into DC. In addition, the 845i has 2 x 12AX7 valves in its input stage and 2 x 6P3 valves as drivers. Plus the two large 845 output tubes that give the amplifier its name. The 845is RCA inputs are on the rear (not always the case with valve amps). Next to them sits a single set of loudspeaker terminals with options for 4, 8 or 16 Ohm connections. We should use the ones closest to the nominal impedance of our loudspeakers. The front panel is simple; two dials on the right one for volume and one for input selection plus an on/off switch to the left and a small bias current meter in the centre. Two switches and four small slots on top allow us to adjust the bias current and eradicate mechanical hum from the three large transformers. Some valve amplifiers offer auto biasing. Not the Line Magnetic, but adjusting the bias isnt too onerous. Flick the switch for the chosen output valve, check the meter, adjust with a screwdriver if necessary. Youre aiming for 70mA. Repeat for the other valves. Finally, tweak the hum-balance slots if you can hear any buzzing (I never did). It sounds complicated but isnt. Just watch your knuckles, those 845 valves run hot. Everyday operation is methodical. Turn the volume to zero, switch the amplifier on, wait 30 seconds whilst it soft-starts. If you turn it off, wait two minutes before switching it on again. This better protects the valves. And dont turn any valve amplifier on without speakers connected you risk damaging the transformer and/or output valves. Looks build qualityThe Line Magnetic wears its underpants on the outside; the valves are all prominently displayed in front of the output transformers (hidden away in the towers behind). Everything appears well screwed together. The finish is gloss black, lending the amp a dark and brooding air and, for some, the antithesis of chic. Using the supplied valve cage designed to keep inquisitive fingers away from not inconsiderable heat dampens the vintage vibe a little. User discretion is advised. Personally, I love the Line Magnetics retro look. Those 845 valves are things of beauty; large, complex and mysterious. With the lounge lights low and the 845is cage removed, theres a real romance to proceedings. Alas, after ten days of use, the 845i gently shut itself down without warning. Its main fuse had blown, so back to (sole) UK dealer VAL HiFi it went. A faulty valve-base and associated diode were replaced. The damage had probably occurred in transit; it transpires that this sample had already done some serious mileage, visiting several other reviewers before arriving at my door. Once repaired, the Line Magnetic performed without issue. Review equipmentThe Graham LS6 standmount speakers (2300, review here) have a manufacturer-rated 87dB sensitivity. Thats average for a standmount of their size and a more than fair test partner for the 845i. KLHs The Fives up for review next also got a brief run. At 87.5dB, their sensitivity is similar. Cambridge Audios Edge NQ streaming DAC (4500) played source. Gold Notes 300wpc PA-10 monoblocks (2600/pair) were used for a chalk-n-cheese power amplifier comparison. I also tried briefly my regular Pro-ject S2 Stream Ultra / Mytek Liberty / SBooster front end with the 845i. However, a slight audible harshness put paid to further listening. That was interesting. In every other system, this combination had shown itself to be on a par with the Edge NQ. The 845i exposed a more pronounced performance delta that favoured the Cambridge unit. Sound qualityI played some gentle classical guitar to (literally) warm up the 845i and I noted a very pleasant sound, even when I wasnt focusing all that much. Then onto Sooki Sooki from Gerald Albrights 30 album for a blast of funk. The sheer force took me by surprise. The 845i had announced itself, sounding much stronger than any 22wpc solid-state design. Want dynamic slam? The Line Magnetic gives us it in spades. At the same time, out the window went any (clichd) notion of bass looseness. Treble was also more direct than I had expected. Sweet n sugary it isnt. More than once was I reminded of the live music vibe felt during time spent with the Klipsch Heresy III and Forte III. However, the 845is treble comes on as beautifully judged. With Brittens 1st String Quartet, it positively shimmers. Thats especially noticeable once the Endellion String Quartet reaches the very highest registers. This is where most other amplifiers I know tip over into screeching. The detail on show is a cut above, coaxing even more information from David Gilmours Great Gig in the Sky (from Live in Pompeii) than previously heard by this commentator. Normally, we hear Bryan Chambers join the song halfway through. In the Line Magnetic rendition, we realise hes present from the beginning, subtly underpinning the vocal acrobatics of Lucita Jules and Louise Marshall before taking centre stage himself. Just glorious. Theres more. The 845i comes on as properly propulsive on The Sound of Afrotronica by Kaidi NK-OK and it makes The Danish String Quartets Prism 1 sound almost achingly poised. Theyre Calling Me Home from Rhiannon Giddens and Francesco Turissi also captures the raw directness of her singing. Its fair to say that it pushes all the right buttons for me. ComparisonsI hooked Cambridges Edge NQ into the 845i pre-amplifier inputs to bypass the Line Magnetics own pre-amplifier stage. The two sound very similar, but the Edge cant quite match the realism or the directness of the Line Magnetic. The sound is slightlypaler, player outlines a little more amorphous.Switching back to the 845i removes a fine mist that, hearing the Cambridge alone, youd likely not notice. That said, other factors might push you closer to the Edge NQ e.g. the convenience of in-Roon volume control. For overall sound quality, the 845i gets the nod. Just. Enter the Gold Note PA-10 monoblocks to go up against the 845is power amplifier. Theyre both operating at the same high level but theres clear water between them on presentation. The 845i has a lighter touch, the Gold Notes favour a darker palette. Whisky drinkers will find the difference analogous to Laphroaig (845i) versus Bowmore (Gold Note). In the coffee shop, wed be talking lighter vs. darker roasts. The Gold Note pair also sound more solid in the bass, mining the Grahams deeper than the Line Magnetic. Maybe 300wpc does count for something? Or maybe its the Italians solid-state nature. When it comes to dynamics though, the 845i eats the 2 x PA-10. It also sounds more filigreed, more refined, with the Gold Note two-fer coming up shorter on a recordings air and room ambience. With pros and cons for each, the choice might also fall to accompanying kit. With the LS6, I lean toward the Line Magnetic but I could (and do) live happily with the Gold Note. With KLH The Fives, the Gold Note comfortably won the day, the 845i sounding inexplicably harsh when paired with this newly revived model. Its a finding that reinforces the importance of properly matching amplifier to loudspeaker. WrapThe Line Magnetic 845i is the sort of product you get out of bed for in the morning. Paired with medium to high sensitivity speakers, it sounds robust and resolving, its extra resolution delivered with a most inviting lightness of touch. Here we have our cake and we can eat it too. Further information: Line Magnetic Credits: Phil Wright Darko.Audio
