New Line Magnetic 508ia Integrated Amp

Discussion in 'Audio Hardware' started by GoldprintAudio, May 20, 2016.

  1. JeffC

    JeffC Member

    Location:
    Catskill, NY
    Sorry for the delayed response. I haven't ordered the tubes because I have a NOS matched pair of 805s that use the top caps I'd like to try out first (I'm currently using the non-capped Psvane 805A-T). I'm waiting to hear back from Line Magnetic about whether the cage will fit when using the top-capped Psvane 805Ts with the lead wires/cap receptacles. I put the cage on when I'm not using the amp along with a makeshift dust cover. I'm glad to hear that you're enjoying the 508IA! I used the amp at NFB setting #3 for the first few months and then found that I liked it even more at NFB setting #2. Those Tung Sol VT 231 black plates are supposed to be fantastic! Please let us know what you think of them. I've really enjoyed my NOS Sylvania VT 231s (the only other 6SN7 I've tried aside from the stock tubes), and of course the Tung Sol 6sU7GTY black glass with black oval/round plates.
     
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  2. adamaley

    adamaley Well-Known Member

    I have the capped 805A-Ts incoming, they should be here next week - I'll report on the fit. I received the 6SL7 and 6SN7s yesterday, but I plan on plugging them in one at a time sometime next week. I switched to NF2 yesterday and I'm still evaluating whether I prefer it to 3.
     
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  3. Seafinch

    Seafinch Forum Resident

    Location:
    Utah
    Nice! Looking forward to hearing your thoughts on the capped 805s.
     
  4. adamaley

    adamaley Well-Known Member

    [​IMG] Couldn't resist plugging the newcomers in for a spin tonight mostly to make sure there were no obvious defects since I purchased them off eBay.
     
    Last edited: Dec 23, 2017
  5. JeffC

    JeffC Member

    Location:
    Catskill, NY
    Happy Holidays!
    What do you think of the VT 231 6SN7 Tung Sols so far?
     
  6. adamaley

    adamaley Well-Known Member

    The recent post was me attempting to upload a pic - failed for some reason. To answer your question, I didn't give them much of a listen - I was just making sure they weren't defective. They were absolutely quiet with no hum whatsoever, which is a good preliminary report in my book. I'm still burning in the stock tubes, and want to get a good handle on the sound before introducing new tubes one at a time. Happy Holidays to everyone.
     
  7. JeffC

    JeffC Member

    Location:
    Catskill, NY
    I heard back from James at Line Magnetic and he says that you can still put the tube cage on the amplifier when you use the lead wires with the Psvane 805T top-capped tubes.

    And in response to my request for some clarification about what the N.F.B. knob selector positions represent (how much N.F.B. each of the 4 settings adds) he said the following: "From 1 to 4 they are -1dB, -3dB,-6dB, and -12dB." He also explained that when you set the input selection knob to Pre In on the 508IA (for the use of a stand-alone active or passive preamplifier), the 6SL7 input tube is still in operation "because it has been connected to the N.F.B."

    Merry Christmas and Happy Holidays to all!
     
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  8. JeffC

    JeffC Member

    Location:
    Catskill, NY
    And in response to a question I asked about whether the 6SN7 tubes are bypassed when a separate preamplifier is used James explained that "6SN7 in LM-508IA is the driver tube. It is still in the circuit even if you are choosing to Pre-IN." I'm not entirely sure what role this information will play in my thoughts about whether to try an active or a passive preamplifier with the 508IA.
     
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  9. adamaley

    adamaley Well-Known Member

    That's good to know. Thanks for the info, @JeffC. Interesting fact about the 6SL7 and 6SN7 tubes.
     
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  10. adamaley

    adamaley Well-Known Member

    Got the Psvane 805T capped tubes today. Bad news on two fronts - they don't allow the cage to close and, secondly, one of the pair was DOA. It doesn't light up. I tested by switching both tubes around, and the lead wires to isolate the issue to the tube. I'll attempt one more time to post images. Is there a post threshold to be reached before one can post images on here?
     
  11. JeffC

    JeffC Member

    Location:
    Catskill, NY
    I'm sorry to hear about this. Rachel at Grant Fidelity will definitely replace the defective tube. She replaced one of my Psvane WE 300Bs when it began shorting. But I thought the whole point of using these top-capped types was that it increased reliability. And I'm most confused about why the cage won't fit. The email I received from Line Magnetic on December 24th said otherwise: "Yes, you can use the lead wires and the tube cages can still be used when putting on the top cap." Keep us posted please.
     
  12. adamaley

    adamaley Well-Known Member

  13. JeffC

    JeffC Member

    Location:
    Catskill, NY
    I can't view the photo you've posted there.
     
  14. Billion$Baby

    Billion$Baby RIAA AWARD COLLECTORS on Facebook

    That's not even CLOSE to fitting. Sucks when you get bad info
     
  15. adamaley

    adamaley Well-Known Member

    Has anyone looked into using either the Elrog 300B or the EML 300BXLS as driver tubes in the amp? These are unconventional 300Bs and not up to standard specs. It would be good to know if they are suitable options for this amp.
     
  16. JeffC

    JeffC Member

    Location:
    Catskill, NY
    I think this is a question that's definitely worth asking LM or to Tone Imports directly.
    Will you still be using the top capped 805 even though the tube cage won't fit?
    Also, I'm wondering how you like the Tung Sol 6SN7GT VT 231 tubes so far. These black glass, black oval plate tubes sure are pricey and I'm wondering how much of a difference they make, especially since according to James of LM these are "driver" tubes in the LM 508IA circuit design. I guess I'm still kind of confused about this since I thought the 300Bs were the the sole drivers and the 6SN7s were preamp tubes. I'm trying to figure out whether it makes sense to try using a separate good quality preamplifier through the 508IA's pre in even if all of the 508IA's tubes are always in the circuit and the only thing bypassed will be the stock alps potentiometer. The 508IA clearly has enough gain and I guess I'm questioning the wisdom of adding another stage of gain before the 6SL7 and 6SN7s. I'll have to audition a preamp with the 508IA to find out.
     
  17. J.D.80

    J.D.80 Active Member

    Location:
    New York City
    I will be following the answer to some of these questions closely. I've always intended on adding a separate preamp to my 508. I find it very difficult to believe that the 6SN7 tubes are anything more than the preamp tubes. It just doesn't make sense to me. That's a question for Line Magnetic to definitively answer because if every single tube is still being used when it's in the Pre In mode, then what exactly is the purpose of even having that option?
     
  18. JeffC

    JeffC Member

    Location:
    Catskill, NY
    Exactly. I suppose, though, one might want to use a particular preamplifier because of its phono section. As I reported earlier on in this thread, James of LM sent me an email explaining that "6SN7 in LM-508IA is the driver tube. It is still in the circuit even if you are choosing to Pre-IN." (He also claimed that one could still use the tube cage with the top capped Psvane 805Ts, but that was clearly wrong.) The fact that both the 6SL7 and the 6SN7 tubes remain in the circuit when using the pre in option was also verified for me by In Living Stereo and their tech. From what I've seen online, it seems this is also true of using the pre in option on the LM 518IA. Since pre in bypasses only the 508IA's volume control I'm thinking of trying something like EMIA's Remote Autoformer attenuator.
     
  19. adamaley

    adamaley Well-Known Member

    I only recently put both the pair of 6SN7s and the 6SL7 into the mix, and I'm simply burning them in before doing any critical listening. My plan is to substitute the stock 6SN7s in, and see what difference they actually brought to the table, then do the same for the 6SL7. I can definitely say the sound is more transparent, less muddy, has better bass, is more linear, and has better detail. There is also more gain - I went from ~11pm to barely going over ~9pm on the dial. As to which tube brings these about these specific attributes, I will find out over time. Were they worth it? So far, definitely. The music is more engaging - especially with deeper tighter bass, and resolution.

    I am also confused as to the role of the different tubes - I was under the impression the 300bs were the drivers. It's a little disappointing as to the lack of information out on the amp. Even the manual lists tube types for the 518ia further confusing the matter. @JeffC can you share the direct contact info for Line Magnetic? Also, much thanks to you for your insight thus far.
     
  20. JeffC

    JeffC Member

    Location:
    Catskill, NY
    Of course!
    Here is the contact info: lmaudio@lm-audio.com
    That's good news about the Tung Sol VT 231s.
    Are you awaiting a replacement 805T from Grant Fidelity?
     
  21. adamaley

    adamaley Well-Known Member

    Yes, I sent out the defective tube for a replacement yesterday. I will stick with the Psvanes since they are supposedly an upgrade over the stock tubes. How did you find the vitage 805s over the stock tubes? Were they an improvement, and if so, by how much? I've seen a few RCA 805s floating around eBay that I've been tempted by for their reasonable price.

    Thanks for the Line Magnetic contact info.
     
  22. J.D.80

    J.D.80 Active Member

    Location:
    New York City
    I recently changed out the 6SN7's to a pair of NOS 1952 Sylvania 3 hole bad boys and the 6SL7 to a NOS Mullard ECC35. The sound stage difference was pretty remarkable. It was a very fun and worthwhile tube swap.
     
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  23. JeffC

    JeffC Member

    Location:
    Catskill, NY
    I haven't had a chance to try the NOS 805s yet. I'm trying to come up with an alternative for the tube cage first. If I really like them I want to be prepared to leave 'em in. I'll give 'em a try soon and let you know! If my experience of the difference between all other NOS tubes and the new production tubes I've tried is any indication I can only assume that they'll be better. But you never know. The NOS tubes are not as wide as the upgraded Psvane 805TIIs or 805TAIIs.
     
  24. JeffC

    JeffC Member

    Location:
    Catskill, NY
    Thanks for the recommendation!
     
  25. adamaley

    adamaley Well-Known Member

    [​IMG]

    Close, but no cigar.
     
    Last edited: Jan 7, 2018

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