Line magnetic 518a

Discussion in 'Audio Hardware' started by Mark broadhead, Jun 26, 2015.

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  1. Mark broadhead

    Mark broadhead Forum Resident Thread Starter

    Location:
    Newcastle England
    Just bought a LM 218a with EL34's, 211 and 12AX7 fitted, quite an amp but in my system it is very bright sounding, I am wondering if this has some bearing on the stock tubes. It hasnt yet played for 20 hours or so - this may be a factor too. I know some members have this amp and wondered what your experiences have been with tube rolling ?
     
    Last edited by a moderator: Jun 26, 2015
  2. GoldprintAudio

    GoldprintAudio Forum Resident

    Location:
    Lexington, NC
    Is it a 218 or 518? (your title and thread state 2 different units)

    And you are sure that it has 211's instead of 845's?

    Swapping out the AX7's makes a pretty noticeable difference. What speakers are you using?
     
  3. Mark broadhead

    Mark broadhead Forum Resident Thread Starter

    Location:
    Newcastle England
    Hi, yes that was an early morning post ! It is a 218, with 211 valves. My speakers are based on a design by Lampizator ( P17 ). My previous amps were Audio Innovations Second monoblocs, a 2a3 based amp which have reached near legendary status in the UK. The speakers are an open baffle design, around 97db/w.

    No question the LM is a fabulous sounding amp, I would just like to adjust the balance slightly with a tube swap....
     
  4. rob303

    rob303 Forum Resident

    Location:
    Denver, CO
    I'm not familiar with Line Magnetic, but I do have experience with tube amps and preamps. In my experience tube amps and tubes need ample break-in before making any changes. I'd wait until about 100 hrs before making a final assessment. As stated above, your preamp tubes (12AX7s) will be where you should focus to make tonal changes.
     
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  5. GoldprintAudio

    GoldprintAudio Forum Resident

    Location:
    Lexington, NC
    As stated above, I would give the unit at LEAST 100 hours, and more like 200 to 250 and then re-visit tube swapping.

    I think starting with the AX7's would be the place to go first.
     
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  6. Mark broadhead

    Mark broadhead Forum Resident Thread Starter

    Location:
    Newcastle England
    Hi Thanks for the advice. Will give it some more time.
     
  7. Rolltide

    Rolltide Forum Resident

    Location:
    Vallejo, CA
    The consensus on the Line Magnetic amps seems to be the stock power tubes are pretty decent but the preamp tubes should be changed. I'd admit there's a practical argument in letting them burn in so you can get a sort of baseline as to what you're improving, but I think there's an equally compelling argument to go ahead and swap out no-name preamp tubes sooner rather then later.
     
    Brian Gupton likes this.
  8. Erocka2000

    Erocka2000 Forum Resident

    Location:
    Brooklyn, NY, USA
  9. Mark broadhead

    Mark broadhead Forum Resident Thread Starter

    Location:
    Newcastle England
    I've checked to make sure - they are 211s with just Line Magnetic written on, so no idea where they were sourced. The EL34s have only EL34 written on. 12 AX7 Line Magnetic again. Psvane maybe ?
     
  10. Erocka2000

    Erocka2000 Forum Resident

    Location:
    Brooklyn, NY, USA
    Did you buy it new? If so, I'd check with your dealer to make sure. Everything I've read and seen (in person) shows them with 845 tubes.
     
  11. GoldprintAudio

    GoldprintAudio Forum Resident

    Location:
    Lexington, NC
    The 218 now comes with 211's standard. So it likely does have 211's since it was a recent purchase (the 218 did have 845's standard previously).
     
  12. Mark broadhead

    Mark broadhead Forum Resident Thread Starter

    Location:
    Newcastle England
    Sorry, I meant the power tubes have 211 on and the logo for LM. Yes they were new.
     
  13. Erocka2000

    Erocka2000 Forum Resident

    Location:
    Brooklyn, NY, USA
    Ah, I was not aware of that change. I wonder if the newer 518's will also come with 211's. Are 845's and 211's interchangeable or does the circuitry need to be changed?
     
  14. Larry I

    Larry I Senior Member

    Location:
    Washington, D.C.
    Mark,

    I have heard the Line Magnetic amp with the DeVore 096 speaker and that combination was not particularly bright. I am also a little bit surprised that your system sounds brighter with the Line Magnetic amp than with a 2a3 amp. I would have expected the two to be similar, with the 2a3 sounding perhaps a touch leaner in the midbass which would also make the sound seem a bit brighter. But, of course, each speaker amp combination is unique.

    As far as changing the sound with a change in tube complement, that might be the way to go. I would start with the 12AX7s because they make a big difference in the sound and the cost will be less than changing the 211s. I am not familiar with current issue 12AX7s. Among the vintage tubes, the Mullards are among the warmer sounding tubes and they should work to tame brightness. However, in three phonostages where I heard comparisons of different vintage tubes, the Mullards did not sound that good to me (a bit murky sounding and they had a "phasey" quality to me). In all three phonostages, I liked Amperex Bugle Boy 12AX7s. They are on the warmish side, though not as warm as the Mullards. The Mullards and Amperex are not cheap, so perhaps you could try some of the current issue 12AX7s.
     
  15. Mark broadhead

    Mark broadhead Forum Resident Thread Starter

    Location:
    Newcastle England
    I believe it might need to be, the perfunctory manual gives alternatives for the EL34's but nothing else. I don't want to give the impression it sounds bad - it is a superb amp f0r the the money ( $ 1500.00 ) - those 211's can really grab a speaker by the scruff ! The output transformers are huge. nothing is omitted in the presentation, its a warts and all sound. Ive never heard a valve amp that could present rock music with such authority, but of course the speakers are very efficient. At 35kg if you dropped it on your toes your dancing days would be over. Great site btw...
     
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  16. Rolltide

    Rolltide Forum Resident

    Location:
    Vallejo, CA
    If I had to guess, they're probably doing this so there's more diversity in their product range. I doubt the 218 sounds like the 518, but if I were a dealer I'd want a better answer to my customer asking what the difference is then "made with better parts".
     
  17. Radiotron

    Radiotron Tube Designer

    Location:
    Montreal, Canada
    The OP should simply let the Chinese tubes break in. Line Magnetic amps are anything but bright.
     
  18. Mark broadhead

    Mark broadhead Forum Resident Thread Starter

    Location:
    Newcastle England
    Hi Larry

    The 2nds are lovely amps, very sought after over here. But they don't have the clout or clarity of the LM even though the tone of the AIs is lovely. It could well be that they are adding something to the sound and I had become accustomed to it !

    I have looked at various NOS options as well as current stock. Your experience is very interesting and noted. I know from previous pre amps the difference that can be made with rolling, the EE Minimax in particular.
     
  19. GoldprintAudio

    GoldprintAudio Forum Resident

    Location:
    Lexington, NC

    Yep, it was a recent change.

    518 is going to stay with the 845's. And the 2 tubes are not interchangeable on these.
     
  20. GoldprintAudio

    GoldprintAudio Forum Resident

    Location:
    Lexington, NC
    FYI, if you are going to go new production on the 12AX7's, I am running new Mullards in my LM 211IA demo with great results.

    For the price, I think these Mullards are quite good. And it will likely soften your top end a bit.
     
  21. Mark broadhead

    Mark broadhead Forum Resident Thread Starter

    Location:
    Newcastle England
    Thanks, a friendly local tube seller would be handy at this point ! I quite like the idea of a Tungsol too. Id better stay away from the Jack Daniels tonight or I will be ordering a brace of NOS Telefunkens...
     
  22. Rolltide

    Rolltide Forum Resident

    Location:
    Vallejo, CA
    I recently purchased vintage Telefunkens on ebay for almost the exact price that current issue Gold Lions would cost. Not technically NOS, but testing basically as such. After that experience I don't think I'll ever buy a new issue preamp tube again, at least not as long as I can get vintage at the same cost.
     
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  23. Larry I

    Larry I Senior Member

    Location:
    Washington, D.C.
    I like Telefunken 12AX7s myself, but, I could not recommend them to someone looking for a less bright tube. They are very lively and dynamic sounding, but, the extension on top and tight and lean bass puts them on the brighter end of the spectrum. I currently run Telefunken ECC803S tubes in my phonostage.
     
  24. Rolltide

    Rolltide Forum Resident

    Location:
    Vallejo, CA
    I guess I'm not recommending Telefunkens specifically as I am just not buying re-issue tubes unless no other options exist.
     
  25. Richard Austen

    Richard Austen Forum Resident

    Location:
    Hong Kong
    There is an amp called the 211IA - it takes EL35 tubes. No Line Magnetic amp takes 211 tubes - they take 845s and are 845 tube amps. Some amps may fit the 211 tube but Line Magnetic is designed as an 845 tube amp and I would be careful about what is being stuck in there - all original Line Magnetic tubes will have their logo printed on the tubes.

    Please take a picture of this tube and the amplifier as it is very strange - it could be that the grey market is rearing its head and someone is copying Line Magnetic - yes there are Chinese companies that copy other Chinese companies.

    This is a link to the 218IA according to Line Magnetic http://www.lm-audio.com/english/xxcp.aspx?dyiji=10&id=218

    You could also contact Jonathan Halpern at Tone Imports as he is the US importer he will know whether the 211 is safe to use. http://www.toneimports.com/lmaudio/lmaudioHome.html
     
    ThorensSme likes this.
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