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Line Magnetic LM-502 CA switchable tube D/A converter

  • Yesterday I began asking myself “Where did all the tube DACs go?”, my renewed interest in which will be revealed in due course. Yes, I’m aware of the glass and gas inside AMR’s DP-777 but, for now at least, I’m focussing on the budget space: hitherto radar-dodging, entry level DACs with tube output stages that sell for US$3000 or less.

    DAR reader Chris Jorg chimed in to bring Line Magnetic to my attention, referred to in some quarters as the ‘Shindo of China’. But it’s not quite that simple. Line Magnetic are a South Korean company whose manufacturing base sits in the Guangdong Province of China. There they make loudspeakers, amplifiers, CD players and – you guessed it – DACs. DACs with tubes output stages no less – which brings us to their LM 502-CA D/A converter…

    Let’s start with its digital inputs, of which there are five: AES/EBU, BNC, USB, optical, and coaxial. Each are capable of decoding up to 32bit/192kHZ PCM. No DSD, no worries. USB comes from the everywhere-all-the-time XMOS but no word if Line Magnetic use the stock code or not.


    The LM 502-CA DAC offers switchable tube (3V) and solid state (2.5V) outputs which gives it a (theoretical) leg up against the mutually exclusive Cary Audio DAC100t and DAC100.

    Again, like the Cary, analogue and digital sections are power by separate transformers. A toroidal handles the former whilst an EI juices the latter. More unusually, a 6Z4 handles tube rectification before the signal sees twin 12AU7/ECC82 bottles.

    Much of this is reminiscent of the original Eastern Electric Minimax which saw a single 12AU7 on its switchable tube output and ESS Sabre 9018 silicon.  Decoding on the Line Magnetic is handled by the slightly older ESS Sabre 9016 which probably accounts for its 8db dynamic range advantage over the aforementioned Cary (which decodes using the more humble ESS Sabre 9023).


    • Frequency Response: 15Hz~50kHz
    • Sampling Rate: 32bit 44.1KHz 48KHz 88.2KHz 96KHz 176.4KHz 192KHz
    • Digital Input Impedance: 75Ω
    • Output Impedance: 2 kOhm (Tube), 600 Ohm (Solid State)
    • Dynamic Range: 120dB
    • Dimensions: 376mm x 345mm x 191.5mm
    • THD: 0.5% (Tube), 0.02% (Solid State)
    • Power Consumption: 24W

    Note the absence of SNR specifics.

    The Line Magnetic LM 502-CA sells for US$1800 stateside and AU$1990 down under.

    Further information:  Line Magnetic (Chinese only) | McLeans Smarter Home Entertainment | Tone Imports

    John H. Darko

    Written by John H. Darko

    John currently lives in Berlin where creates videos and podcasts and pens written pieces for Darko.Audio. He has also contributed to 6moons, TONEAudio, AudioStream and Stereophile.

    Darko.Audio is a member of EISA.

    Follow John on YouTube or Instagram


    1. The original Minimax, which I still own, claimed 135db DR and originally sold for about $750. The plus version sells for $1100.
      Wonder if the LM adds an extra $700 worth of meat-on-bones.
      Not sure about that “orangy” color either.
      FWIW – Their amps sound quite decent.

      • Yes, it’s a shame that I never got to hear the Plus version. Didn’t they ditch the volume control? I suspect that’s why I passed.

    2. Tubed DACs haven’t gone anywhere, if you ask me. Gracing my desk is the mighty Grant Fidelity TubeDAC-11. It has a choice of tube or solid state output, and analog and digital inputs with a volume control knob, headphone jack, and toroidal transformer for $350. I’ve rolled a $9 Russian Rocket 6922 into the DAC for punchy, layered, expansive sound. Bliss on the cheap, it is.

      • Maybe not. But they seemed to have slipped from public consciousness as more of the bigger brands have (finally!) joined the computer audio game and crowded out the earlier, progressive designs from Pacific Rim manufacturers, a good few of which featured tubes. Your Grant Fidelity TubeDAC-11 is a Chinese derivative, no? Apologies if I have that wrong.

    3. Line Magnetic is definitely the Chinese manufacturer that I would have no reservation with whatsoever. A lot of great retro design gear coming out of there at decent prices..

      Tone Imports is the US distributor for LM here in the US:

      I considered the LM 755i Field Coil Speakers:

      But… you just have to love the Line Magnetic 41.2 212 Single Ended mono amplifiers:

      • CRIKEY, Junker, that looks like DR Frankenstein just wheeled it in too charge up Junior!

    4. ”Yes, it’s a shame that I never got to hear the Plus version. Didn’t they ditch the volume control? I suspect that’s why I passed.”
      At $1100 vs $750 and with mediocre USB implementation I don’t think it had the same success as the original.

      ”But… you just have to love the Line Magnetic 41.2 212 Single Ended mono amplifiers:”
      I’m sure my wife would be thrilled if I brought home a pair of those for our living room.

    5. Their website – in Chinese only unfortunately – is
      I have 2 of these now (one in the funky gold colour and one silver) they go for around $750 in China and IMO stand their corner with other DACs, painlessly replaced a Weiss Dac 202 in one of my systems. Swapping the 12AU7 input tubes with Genelex Gold Lions really made it sing, lots of wet tuby goodness, very easy on the ear especially with poorer recordings This company makes quality stuff, the LM-518IA integrated is the best I’ve ever matched with both my Zus and Omega 6XRS, however everything they make is BIG and esthetically an acquired taste I’d say.

    6. I had the Havana (heavily modified), original Minimax and now the Plus version. The usb module is OEM Hiface the same as the Metrum Hex usb module…With 2x double Audio GD AOP it’s th best DAC in the 1000$ region.

    7. Thanks for throwing some love at Line Magnetic, Darko.
      I wrung hands for nearly six months over my tube amp search and stumbled across LM Audio right before pulling the trigger on another Chi-fi unit…. I am now the proud owner of a 211ia Integrated from LM.

      I was actually just checking out the specs on Leben’s honey toned CS300 intergrated (knowing damn well I couldn’t afford it) when I came across Line Magnetic. Jeff Rotunda (I believe he’s a friend of Mr. Ebaen’s ) sells LM gear to supplement his gigabuck Shindo gear and Leben stuff out here in California.

      Line Magnetic’s flagship amp is far and away the most audacious looking amplifier I have ever seen… But only costs around $25k…. Not that I have those means but you could spend that much money putting together a very unremarkable system with McIntosh separates. It probably sounds excellent but you aren’t exactly getting exotic hifi for your 25k when every other house in Newport Beach and Malibu is sporting the same stack in their living room and these same ‘high end’ pieces can now be sourced at the friggin mall from Best Buy.

      The Line Magnetic unit is bizarre, bewildering, stunning , extraordinary and lust invoking all at the same time. Sporting that gargantuan Tungsten Filament front and center like its flipping off the industry… China only makes crap huh?

      $1650 is considered entry level in the tube integrated market…. But the LM211ia is pure high end to me…. absolutely gorgeous sounding… Mind you I’d love to see a second set of inputs and a headphone jack…. but for the money…. no contest.

      Thanks for giving these guys some run…. they Do deserve it. Good on ya!

    8. IMO, the reason tube DACs have been few and far between, is because the ones that have tried (Eastern Electric) have not done super well. From what I recall from reviews of the Minimax, the SS output was usually preferred over the tube output. Not saying there is no place for tubes. I personally like their sound in a preamp. Not sure why they havent done so well mated up to a DAC. IMO, the opamps etc have just got that good….

    9. Yeah there was a blind DAC shootout where the entire panel almost unanimously preferred the Minimax solid state output over the tube. They were all pretty surprised.

      It is a shame the Minimax product has been swept away and forgotten. The DAC world has changed so much since 2010.

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