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Line Magnetic 518IA, WOW.

Discussion in 'New Gear - Values' started by Spektre, Aug 29, 2017.

  1. Spektre

    Spektre Brit alert

    Messages:
    795
    Location:
    Peterborough, England
    After some years of upheaval I've managed to unbox some gear I've had waiting for a new home, one of those being the Line Magnetic 518IA SET. This amplifier has me thinking about the hierarchy of just how much of your funds you should allocate to each part of that chain. Source, Amp, Speakers has always yielded the best results for me but the stuff this amp is unearthing from my Audiolab 8200CD is amazing. Synergy with the KEF's is pretty good and the tonality, power and soundstaging abilities of this combination is close to the best I've heard of any system I've owned, certainly the best I've heard from CD, images simply leap out of the LS50's. Volume level is not a problem although I have noticed that not that much happens after the 10'o clock position is reached, but given that I'm in a small space the output is more than sufficient. I've also used the CDP with my favourite Creek Destiny 2 thats been a solid performer for many years as well as the KEF's. To be honest the latter didn't work well together with the bass being overpowering in my 11 x 10 room, I resorted to using the foam bungs as the midrange was taking a beating, the Creek and my Epos ES11 are far happier together.

     
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  2. Hyfi

    Hyfi Addicted Member

    Messages:
    5,507
    Location:
    Bucks County, PA
    I have heard nothing but good reviews for the LM gear. Congrats and enjoy!
     
  3. Spektre

    Spektre Brit alert

    Messages:
    795
    Location:
    Peterborough, England
    Like so many things Hi Fi this amp isn't perfect. There is a lack of deep bass, driving the LS50 with the solid state Creek produced more extended upper bass. One of the things I've never seen mentioned in reviews is bass speed and it does appear to be a little lazy, lagging behind the midrange and treble just a hair. This could be down to the amp speaker combination though, driving a more sensitive floor stander might give better results than the KEF's at the lower end.
     
  4. Art K.

    Art K. The Voodoo You Do! Subscriber

    Messages:
    24,040
    Location:
    Corvallis, Or
    Well done, Gavin. I love the LS50's with my Heed amp and LM 515 CD player. Stands are very important relative to getting the best bass from the LS50's. Weekend before last I tried the LS50's on my Atacama stands and quickly returned to the Skylan's. That's an awesome amp you have!
     
  5. Spektre

    Spektre Brit alert

    Messages:
    795
    Location:
    Peterborough, England
    Hi Art, long time... I don't think the LS50's are bass shy as I had too much when using the Creek, they are certainly punchier low down than the Epos, I may experiment in the future with some other stands though. Yeah, the amp is awesome, build quality is like a Rolls Royce. I hope I don't have to move it from its stand too often as its at the limit of what I can lift. You always think that reviewers exaggerate about the heat from these amps but I can feel it radiating heat 3 feet away.
     
  6. Erocka2000

    Erocka2000 Well-Known Member

    Messages:
    734
    Location:
    Brooklyn, NY
    You can extract more bass from the 518 depending on which driver tubes you use. If you can get some RCA black plate 6L6GCs, those would be best. For a budget, try the new Tung-Sol 6L6GCs, which are also quite good for the money.
     
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  7. RGA

    RGA Super Member

    Messages:
    1,123
    Location:
    Hong Kong
    I drove the LS-50 for quite some time with my LM219IA and I have auditioned the LS-50 on a number of 100watt + SS beasts.

    My main recommendation these days to most people is to do your best to try and buy "synergistic systems" which as an Audio Note owner (system approach) always made logical sense. But the brand doesn't matter - what matters is to buy an amp the speaker maker designs for. KEF didn't design this loudspeaker for SET amplifiers (or tubes for that matter). This is obvious when looking at the measurements or even the spec sheet.

    So as an end user, you, are probably better matching with an appropriate amp. SET amplifiers are wonderful - my favorite, BUT their biggest Achilles heels are 1) lack of power and 2) lack of power into varying/low impedance loads. That's why it generally takes rather massive ones to be able to competently drive speakers like the very VERY difficult to drive KEF LS-50 properly and even you are finding it still has trouble.

    The KEF is low sensitive AND it has a low and varying impedance load. King Ip of KingKo audio brought the KEF to his store to be a demonstrator speaker and he dumped it almost right off. His amps can't drive them properly even in a small (and I mean very small bedroom sized room).

    The 219IA with massive transformers drive them well but I still would not drive them in a larger medium room or larger. And it still wasn't an ideal match by any stretch. Part of this is the lack of damping factor in SET amplifiers. More damping factor = more negative feedback = worse sound. But high damping factor has more driver control into low impedences which is where bass is. Tube changes won't fix this either.

    Now of course I am probably far pickier than the average bear (and about different things) and because I generally dislike SS it is a difficult task to find an amp for the KEF. But for the KEF - a larger push pull amplifier in the 70 watt+ range and on the 4 ohm tap is what would be needed. You should have the KEF running from the 4 ohm tap on the LM as well if it is not already.

    I guess what I am advising is not to try and shoehorn an amp into a speaker not designed for the amps. For example for $1,995 I would prefer the Spatial Audio M4 which is also 4ohm min 3 ohm but is supposed to be fairly stable. And it is a full ten times more sensitive making it significantly easier to drive.

    http://www.spatialaudio.us/hologram-m3-m4

    For $2800 the M3 Turbo S has bass to 32hz and is 94dB sensitive. Personally I would take these over my KEF in a second if I were going to use a 20 watt SET amp(or any other amp for that matter). Plus they come with 60 day returns and 20 year warranties. And unlike KEF - made in America which some people seem to like.

    http://www.spatialaudio.us/hologram-m3-m4

    But they're pretty big (OTOH no stands required). Anyway these are the sorts of speakers that are very good sounding places to start with tubes and aren't horns with their often shouty treble bands.
     
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  8. Poultrygeist

    Poultrygeist Lunatic Member

    I agree with RGA. The Spatials are SET friendly and a much better match. But when in use they'll need to be pulled out at least 3 ft from the walls.
     
  9. Spektre

    Spektre Brit alert

    Messages:
    795
    Location:
    Peterborough, England
    The KEFs were fresh out of the box at the beginning of the week and are now starting to loosen up and provide adequate bass, this combo is so good in my tiny room that it has me (finally) thinking about selling the Epos ES11.
     
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  10. Poultrygeist

    Poultrygeist Lunatic Member

    Be careful as driving low efficiency speakers with flea watt amps can cause damage. Actually more damage than the reverse.
     
  11. rskcali

    rskcali New Member

    Messages:
    2
    I am relative newbie to all things audio. Poutrygeist, just curious what sort of damage can occur running low efficiency speakers with flea watt amps? I am between amps right now and temporarily running a Topping TP20 Mk II digital amp (I think 25 wpc) into my KEF LS50s. It actually sounds pretty good in my very small room, but your post raises concerns. Thanks.
     

     

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  12. rskcali

    rskcali New Member

    Messages:
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    I apologize if my post is off topic for this thread. This was my first post to this site. Thanks.
     
  13. vonclod

    vonclod AK Subscriber Subscriber

    Messages:
    1,452
    Location:
    Vancouverish
    Very nice..One day I will acquire a LM amp or integrated, does that one run 211s or 845s?
    I have run my LS50s with a 14w SET(KRAudio) and it was very satisfying..best synergy of all my amps.
     
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  14. RGA

    RGA Super Member

    Messages:
    1,123
    Location:
    Hong Kong
    Simplistically - tweeters in loudspeakers do not like distortion and if you run a low watt amplifier and push the amplifier into high distortion (clipping) it is possible to blow the tweeter(or the woofer or both but usually the tweeter goes first). The reason high watt amps are less likely (but still possible) is that they will not likely to be pushed into "clipping" and won't send high distortion signals to your loudspeakers.

    Low efficiency loudspeakers also tend to be low impedance at certain frequencies - so let's say you are driving the KEF at 90decibels and you have a 10 watt amplifier. The speaker is 83dB sensitive and

    83dB requires 1 watt
    86dB requires 2 watts
    89dB requires 4 watts
    92dB requires 8 watts
    95dB requires 16 watts.

    So you are trucking along no problem but all of a sudden you get into a crescendo (loud bit) in the music and if that occurs in the bass where the KEF dips to 3 ohms then the speaker asks the amplifier for more than double the power. The KEF is rated as 8 ohms but in a bass passage it drops to 4 ohms or less thus it asks the amplifier for double the power to reproduce the lower frequency.

    So for the KEF speaker to reproduce 92dB at 4 ohms instead of using 8 watts that it was using it now requires 16 watts.

    The amplifier immediately clips (because it can't reproduce 16 watts it can only reproduce 10) and then sends distortion to the speaker.

    Most speakers are pretty tough and can take a fair amount of distortion for short periods (and amplifiers can often reproduce more power than rated spec for short duration but then - not always). Many tweeters can handle about 10 watts of distortion. Which, weirdly enough can make very very low watt amps safer because they can't send enough distortion in watts to damage the speaker. A 3 watt SET can only send a total of say 5 watts of distortion (if it can go 50% above rated spec) to the speaker so if the speaker can handle 10 watts distortion it can't be blown by a 3 watt SET. Well so the theory goes - I am not about to test that. :)

    The other issue is that not every amplifier is designed equally - some are simply built better where the rated output is across all frequencies while others are rated only for 1khz. Some can go above their rated output in short duration while others don't meet their rated spec. So some 8 watt amps may only be 4 watts in reality and other 8 watt amps may reach 12-16watts.

    Having said all that, SET amplifiers sound so darn good they tend to make every speaker sound a helluva lot better regardless of the sensitivity (if you can live without high volume). BUT, it's not an ideal match and it can cause damage if you turn the volume too high. If you hear distortion turn it down.
     
    Last edited: Sep 4, 2017
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  15. Poultrygeist

    Poultrygeist Lunatic Member

    see RGA's post
     
  16. Spektre

    Spektre Brit alert

    Messages:
    795
    Location:
    Peterborough, England
    845's and damn good it sounds too.
     
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  17. Spektre

    Spektre Brit alert

    Messages:
    795
    Location:
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    Before the KEFs were run in I briefly powered them with my Creek Destiny 2 (voltage is switchable between 240v and 110v) and the results were not great. There was an opacity and vagueness to the sound that had me wondering if this was the same amp I'd loved so much over the years. Now the LS50's are fully run in I thought I'd fire it up to quickly compare it with the LM518IA for no other reason than I could, the differences between the two were not extreme to my ears but I'll share what I did hear. The Destiny definitely had more bass weight and extension with the initial slam from percussive strikes being more forceful, the LM still somehow manages to be satisfying though. Midrange and treble were very similar tonally with the Destiny being just a touch drier here, acoustic instruments and voices being a little more lifelike through the LM, but if you couldn't compare you'd never know. Sounstaging and imaging was a clear win for the LM being higher, deeper, wider, more focussed and holographic but the Destiny is still pretty good. I think if you were demoing these two in a dealers the amp you'd go home with would depend largely on budget and personal preference, they both have things to recommend them. I'll probably be unboxing and setting up my Acutus SP at some point next week so look out for photo's.
     
    Last edited: Sep 15, 2017
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  18. datafone

    datafone Super Member

    Messages:
    2,303
    Location:
    Bris', Australia
    Most valve amps soft clip, they don't clip hard like most SS amps do.

    There are some valve amps that will clip hard but most won't (this is circuit dependent), and there are also some SS amps that are designed to clip soft, but most clip hard.

    The other factor in looking at compatibility between speakers and amp is the impedance curve across the frequency response, some speakers are more benign in variation in impedance and provide a more amp friendly load not dipping too low at any point.

    I drive 87db sensitivity/nominal 8ohm impedance mini monitors that don't drop below 5.8ohms (they surprise with the level of bass they can do for their size also), I use a Triode strapped AB PP EL34 amp with them (around 20w a channel), i never have an issue with driving them to louder than sensible without any fear of damaging my speakers, or to a point of any objectionable distortion, mind you these can driven with 300watts of SS power no problem as they are tough and of course the control of the mid-bass will be a little better and faster acting with that sort of power.

    Not saying the LM and Kef's are a ideal match with the Kef's as they are not a real friendly load and the LM being 22w. the Kef's I expect will like a amp with a good bit of current drive. just suggesting that there are more factors to consider. At low levels in a small room the MM/Kef combo should perform OK and I imagine will be very pleasing all the same.

    BTW, love the LM amps the build and level of quality, yet to hear one though.
     
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  19. datafone

    datafone Super Member

    Messages:
    2,303
    Location:
    Bris', Australia
    Not taking anything away from what RGA has said though.
     
  20. datafone

    datafone Super Member

    Messages:
    2,303
    Location:
    Bris', Australia
    As far as I'm aware these types of amps run into distortion well before their max power figure so more reason to be careful.

    Listen for brake up in the high frequencies and if you hear a hint of this back off the volume dial ASAP. Details on this stuff in RGA's post of course.
    I'm just pushing the point to be careful with this combo.
     

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