Line Magnetic LM-805iA Integrated Amplifier Review
This interesting new mid-price Chinese valve amplifier gives Mark Gusew a warm glow…
LM-805iA Integrated Amplifier
AUD $6,499 RRP
As is so often the case, once you've been bitten by the hi-fi bug, you have it for life – what starts as a hobby can take over your whole world. That's certainly what happened to the two brothers who founded Line Magnetic Audio in 2005. It's now a successful family business, with two factories and with one of the largest R&D amplifier facilities in China. The company makes a wide variety of products including classic Western Electric replicas and components for well-known OEMs around the world. With the support of Line Magnetic Australia, the new local distributor, this is a brand to watch for tube fans interested in real-world priced products.
The LM-805iA that you see here is a single-ended triode integrated using a single 805 output tube per channel, working in full Class A and putting out a healthy (claimed) 48W RMS per channel. The input stage uses one 6SL7 and two 6SN7 valves, with the driver stage making use of two 300B valves. There's a pair of specially built ultra-wide bandwidth EI transformers with output taps for 4, 8 and 16 ohm loudspeaker loads.
Line Magnetic doesn't scrimp on the construction, with high-grade parts used throughout, like an ALPS volume pot and MIT and Mundorf N-Cap capacitors. The amplifier is built to Australian 240V AC power standards, not just 220V that other countries use. They use point-to-point internal wiring, and the unit comes with an infrared remote control for convenience.
Weighing an osteopath-friendly 42kg, this is one solid amplifier – and requires assistance to unbox and position. Our sample came strapped to a mini pallet, packaged and secured very well, ensuring its safety in transit. Once unboxed, all connections should be made before powering up the amplifier, a general must for valve gear. There are three pairs of line inputs, but as there's no phono preamp section, you'll need a separate box to use a turntable. You can also bypass the amp's preamplifier section to use it as a power amplifier, should you so wish.
I was pleased to see that it comes with a comprehensive Australian-produced operation manual, with Campbell Nunn from Line Magnetic Australia keen to ensure that every new unit is trouble-free and giving its best. He's well aware of the variability of audio products coming out of China but is confident that Line Magnetic's management's ethos is committed to quality control and longevity. The company has a proven track record over many years, he points out; indeed it's been the recipient of multiple awards including the Golden Winner of Chinese Good Design Award and the German Red Dot Award, amongst others.
The valves used in the amplifier are sourced directly from the Psvane and Shuguang factories, and then screen printed with Line Magnetic branding. There are plans to offer a range of upgraded replacement valves for customers from Psvane. In particular, its excellent WE and ACME series valves, sometime in the future, ideal for customers who love to tube roll. Standard power valves have a quoted life of approximately 1,000 hours, and the input valves should last around 5,000. Prices are $120 each for the 805s and 300Bs, the 6sn7 is $40, and upgrading the 805s to Psvane high grade types is $680 per pair.
The LM-805iA comes with a removable tube cage, and the adjustment for the tube bias and hum balance is at the top of the amplifier next to the valves. Using the amp's meters, the bias can easily be adjusted to around 120mA, although I found it perfectly set when the amplifier arrived. Those same meters can be switched to show the power output of the amplifier, rather than bias, with the choice of having the backlight on or off.
In the month or so that I had the LM-805iA, it performed in a totally trouble-free way. The bias setting was rocksteady and didn't require tweaking. The controls are just right, with a nice feel and the remote control was especially useful. The yellow/orange glow of the meters is lovely to look at, positioned below the glow of the large 805 valves, so I kept the backlight on all the time. The 30-second soft start is sure to extend the life of the valves as power is applied gradually. The only issues you need to be aware of are the unit's size and weight, and the amount of heat that it generates.
Driving my reference Revel F228Be loudspeakers, I was immediately impressed with the sound of the LM-805iA. Dynamic and punchy with a clean midband and detailed top end, its tonal balance is less coloured than classic tube amps I have tried. There's a touch of added warmth, but it's easily neutral enough to use as a review tool, for example. It will tell you all about components before or after it in the system chain without any problems, or indeed the quality of recordings.
For example, the Sheffield Labs album The King James Version is a live performance recorded direct to the master disc, so is impressive to listen to despite being recorded back on July 1976. Harry James and his Big Band were at their best on Blues Stay Away From Me. Although not the loudest track on the album, it highlights the tone and dynamic of each instrument, particularly the horns. Through the LM-805iA, the trombone solo had incredible verve, with a magnificent tone and just the right amount of bite. It captured the album's live feel, with the players in the same room together – complete with oodles of detail, texture and atmosphere.
Due to way it was recorded, this album doesn't suffer from the overuse of compression, and the Line Magnetic delivered large dynamic swings with great pent up energy and attack. You could call it authoritative, well-controlled and commanding. The leading edges of notes were not softened or slurred, yet the amplifier never sounded harsh. This was especially noticeable on Harry's trumpet which can be piercing through the wrong equipment – yet here it was never unpleasant, instead sounding like a real instrument.
It told me a lot about the way Pink Floyd's classic Wish you Were Here was mixed, too. This dry mid-seventies Abbey Road recording has a title track that didn't feel the least bit truncated or compressed via the LM-805iA. The strummed guitar and vocal line was quite forward, just as it should be; there was no artificially warm 'burnished copper' sound, just a balanced presentation which I found very enjoyable to listen to.
Spatially it's excellent at the price. One Thing by Neil Young & the Blue Notes was a delight, with the interplay between the electric guitar and the saxophone a real highlight. Being well recorded, you can hear the long reverb tails of the instruments being played, as well as their location in the recorded acoustic. The overall effect was of real, tangible music rather than something that's artificially processed to sound impressive.
The amplifier has a four-position NFB (negative feedback) control which I left on its minimum setting, but you can change it while the music is playing to get the sound that suits you. The added feedback drops the overall volume a couple of dB, having the effect of shrinking the width and depth of the soundstage and blunting the focus of the performance, as well as the overall dynamics – at least to my ears, in my own system. Yet it's a good feature to have because everyone's circumstances are different, and it's nice to have the choice.
I also used the LM-805iA with less efficient loudspeakers to see if it has enough power to make them sing. I tried the excellent Spendor Classic 4/5 mini-monitor which has a claimed 84dB (2.83V @1M) sensitivity. This is low by modern standards and way less than my Revels' claimed 90dB. Yet the Line Magnetic drove this little loudspeaker well, with more than enough power available to make the pair go plenty loud even in a large-sized lounge room. This amplifier may have a claimed rating of only 48W RMS per side, but often valve amps can sound more powerful than solid-state amps of the same rating – and that was the case here.
Overall, the Line Magnetic LM-805iA is an impressive tube integrated that offers fine value for money. Single-ended triode amplifiers have a certain charm that many, including myself, cannot fail to enjoy. The 805 valves in this configuration seem to have many sonic virtues with few downsides. It's powerful enough to drive most speakers cleanly, is tonally neutral with a welcome touch of added warmth and it looks more expensive than it is. As such, this is a worthy recipient of StereoNET's Gold Applause Award.
For more information, visit Line Magnetic.
Starting his first audio consultancy business in the early ’80s whilst also working professionally in the electronics industry, Mark now splits his time between professional reviewing and AV consultancy.