New Line Magnetic 508ia Integrated Amp

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

  1. adamaley

    adamaley Member

    That's good to hear. Even though, I've read about the 219s driving SF Guarneris, I'm still a little skeptical over the lower wattage Line Magnetics (219 & 518) driving tougher loads. Short of receiving feedback on actual experience, or hearing them myself, the 508s seem like the safest bet.
     
  2. Seafinch

    Seafinch Well-Known Member

    Location:
    Utah
    Ok guys. I need a little input. Yesterday I had my 508ia all day (I work where I listen). Last night I went to my kitchen to grab some food and when I came back to my office the amp was buzzing really loud through the speakers (I think both, but I turned it off pretty quickly before I checked for sure) and the volume control made no difference - I could turn it all the way down and the loud buzz was still there. The other thing of note was that the 300B on the right hand side was glowing pretty purple. I turned it all off and tried turning it on an hour or so later and the buzz was still there (forget to check if it was in both channels). After sending a couple emails out last night I realized I should find out if it's both channels or just one - maybe it doesn't matter - I don't know. This morning I turn it on and it's all working fine. No noise. Sounds great playing music.

    Does this seem like a tube issue? It does to me, but before I drop some money on some new 300B's I'd love to get a couple opinions. I don't have a LM dealer near me, so worse comes to worst I'd be taking it to a tech at a local shop that has worked on stuff before. But if this seems like normal bad tube behavior I'd rather just order tubes.
     
  3. JeffC

    JeffC New Member

    Location:
    Catskill, NY
    When I had a problem with a new Psvane WE replica 300B tube in the 508ia the noise was startlingly loud in the right channel. It really sounded as if a few large boulders were tumbling down a flight of stairs and the volume control made no difference. That tube was also hotter than the other. I shut the amp off after no more than 7 or 8 seconds. It turned out to be a short (after about 9 hours of use) and Grant Fidelity replaced the tube for me. On another, earlier occasion, just after I had purchased upgraded Psvane 805 tubes, I began hearing an intermittent hum in the left channel, also unaffected by the volume control. This was not the incredibly loud and startling noise I heard when the 300B tube shorted. Since I'd only recently put the new 805 tubes in, I was convinced it was the culprit and so packed them up to return to the seller (in China) and rolled the stock 805 tubes back in. Everything sounded fine for the next day and a half, until I started to hear the same humming sound again, and less intermittently. Then I swapped the NOS Sylvania VT-231 tubes I'd purchased from Brent Jesse and the hum moved from the left to the right channel. It was a good thing that I hadn't sent the 805 tube back because it turned out not to be the problem. Instead it had been a preamp tube I'd been using with no problem for months that just happened to act up around the same time I'd decided to install new power tubes. Brent Jesse surmised that it may have been "a tiny flake of cathode material that has migrated into the grid of the tube over many heating and cooling cycles. You may be able to resolve the problem yourself. Remove the tube and, holding it upright, tap it very firmly on a table top. Not hard enough to break the center stud, but firmly. Hold the tube upright and tap it firmly with a wooden pencil. The object is to knock the flake out of the grid and stop the high resistance short that is likely causing the intermittent hum. Reseat the tube and give it some time to burn in again and the noise should be gone." I gave this a try and couldn't get the hum to go away so Brent replaced the faulty tube.

    I think it's really important first to narrow down the faulty tube to one channel and work from there. Your post on Sunday described a substantial drift in bias which you associated with a change in your enjoyment of the music. Do you recall which channel was out of bias and by how much? When I first rolled in my new 300Bs and checked the bias, the tube that eventually had the short was reading way off--instead of 120, it read 140. I simply proceeded to recalibrate the bias for that side. In retrospect, however, I realize I should have seen this as a sign that there was a problem. At the time I was not aware that the 300Bs in this amp are linked in a cathode bias arrangement with the 805 tubes. My dealer's tech explained that in the LM 508ia "the bias control is actually biasing the 300B. That current through the 300B tubes cathode resistor is what creates the bias for the 805." (The moral of this particular part of the story is that you've got to dial the bias settings way back before you swap either driver (300B) or power (805) tubes in this amplifier.) I did not see any color change when my 300B tube shorted. Was the purple glowing you describe relatively amorphous in nature and associated with the inside surface of the glass bulb (one of my 300B tubes displays this kind of glow and I understand that it is normal) or was it emanating from a specific elemnt inside the tube like part of a wire or a plate?
     
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  4. MikeG777

    MikeG777 New Member

    Location:
    Olympia, WA
    Still for sale?
     
  5. Seafinch

    Seafinch Well-Known Member

    Location:
    Utah
    Wow. Thanks for all the info. Not totally sure if I’m experiencing the same thing, but I’m going to send you a PM and pick your brain a little more.
     
  6. adamaley

    adamaley Member

    I'm looking to purchase a used LM508ia. If anyone is looking to sell, kindly PM me. Thanks
     
  7. MiesDavis

    MiesDavis New Member

    I'm driving ATC SCM40 V2's with the 508IA without even a hint of an issue. Getting hard to imagine a better amplifier for my speakers.
     
    Seafinch and noladaoh like this.
  8. MiesDavis

    MiesDavis New Member

    Also, does anyone know what the comparable 805 is to the stock tube? I bought the TJ Full Music 805 and it added some magic/focus to the mid-range but didn't have the same low end grunt. Thinking I might just get a backup pair of the stock 805's.
     
  9. JeffC

    JeffC New Member

    Location:
    Catskill, NY
    I purchased a pair of Psvane 805A-T for the 508ia and definitely found that they had even a bit more grunt than the stock tubes. These are somewhat bigger tubes width-wise. I ordered them through Amazon because I really couldn't find another place to source 805s outside of Ebay. That was in May. I'd reached out to Rachel at Grant Fidelity about this at the end of April and she told me they didn't carry the 805s because there really weren't any popular 805 amps available. I told her about the LM amp and she happened to be responding to my emailed queries while she was at an audio show in Shanghai. She sent me another email the next day saying that she'd actually had dinner with the LM people who verified for her the growing popularity of the LM 508ia and she said she'd check with the factory and hopefully would be offering the better quality 805 tubes in the near future. Yesterday another member here alerted me to the fact that Grant Fidelity is now selling the Psvane 805T, which is the capped type of this tube for $285 a pair. I wasn't aware that the 508ia could use these capped types but Rachel has this note on her page:

    "Please note that we only have the capped type 805-T in stock now. The uncapped type (805A-T) has higher shipping damage rate due to a different internal structure so we are not providing the uncapped type for the time being.

    We have stocked the cap lead wire for the 805-T tubes provided by Line Magnetic for Line Magnetic 805 amp owners. Your LM 805 amplifier can use the capped type with the lead wire and your tube order will be shipped with a pair of wire free of charge."

    I'm assuming that the lead wire would attach to the curious protuberance just behind tube sockets V01 and V02 on the amplifier. I've often wondered what those are for. I guess I'll have to contact Grant Fidelity for more information on this.
     
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  10. adamaley

    adamaley Member

    Keep us posted as to how the 805T tubes sound. I have a 508 incoming and would be interested in your thoughts in order to determine tube purchases once the dust settles.
     
  11. adamaley

    adamaley Member

    Has anyone rolled the 300B tube to good effect?
     
  12. brody836

    brody836 New Member

    Location:
    Palmdale, CA
    I've heard the EML 300B's sound good. I purchased JMAC's LM508 and have been enjoying it with Tekton DI's. The Psvane 805 T/2 previously mentioned did just as described, improved the bass significantly and the midrange a bit.
     
  13. Encore

    Encore Well-Known Member

    Location:
    Denmark
    I don't own an LM but I a pair of EML 300B XLS replaced a pair of Shuguang Black Treasures in my Audio Note Kit One, and that was a clear improvement. Lower noise (blacker background), more resolution, better bass and a bit more power, I think. Compared to the Shuguangs, the EML's can sound a bit recessed in the mids on some recordings, but all in all they are an improvement. And EML even gives you a 5,000 hour warranty if you register your purchase.
     
  14. IanL

    IanL Forum Resident

    Location:
    Oneonta, NY USA
    Congratulations on your new amp!
     
    valfy likes this.
  15. valfy

    valfy New Member

    Location:
    Norway
    I've had this amp with some pretty good tubes for a few days now. The amp has about 125 hours of playtime and the tubes about 75.
    The tubes are:
    Psvane WE300B
    Psvane CV181T-MK2
    Psvane 805A-T
    Tung-Sol 6SL7

    Still breaking it in, but I'm really really really loving it in combination with my AMR DP-777 SE dac and Klipsch Cornwall III speakers.

    Yeah, boring I know, but the dealer sells these as a "pack" for the amp. Will definitely do some rolling when it's all broken in and I know the amps sound perfectly. Except the WE300B's, they are to expensive, haha.

    It's not clear from the manual if setting 1 or 4 gives the least Negative Feedback, but some research and listening has lead me to thinking that 1 = more NFB and 4 = less NFB.

    For example:
    Does 4 equal zero NFB, or is there still some? I find the sound much more mellow and rich with the setting at 4. If 4 is the highest amount of feedback I guess I can find a new hobby. :D

    It also gives me less gain, which suits my sensitive Cornwalls.

    No hum from the amp, minimal hum for the speakers even without finetuning the hum-controls.

    The only negative thing I can mention right now is the damn watt meters aren't moving when I'm listening at low to moderate volume.
    The first step should have been 0 to 1 watt instead of 0 to 10 for us with sensitive speakers, lmao.


    Some pics of my 508 and 518:
     
  16. valfy

    valfy New Member

    Location:
    Norway
    Damn, I can't edit posts? The pics are way too large, so here they are again:

     
  17. IanL

    IanL Forum Resident

    Location:
    Oneonta, NY USA
    Hi Valfy, nice gear! So you have both a 518 AND a 508?! Awesome. Have you used the 518 (that's the one I have) with your Cornwalls as well? How is the match? I am considering some Cornwalls but my experience with Klipsch makes me concerned about brightness. But the models I owned before were KG4.2 (which WERE bright, but I also had them powered by an Onkyo HT receiver, so I guess I deserved that).
     
  18. valfy

    valfy New Member

    Location:
    Norway
    Thank you good sir!

    Yeah, I'm suddenly stuck with both haha. Bought the 518 used but before I got it into my house an almost brand new 508 with these tubes popped up in the used market. I knew it was gonna be sold quickly, so I just had to take my chances. :idea:

    518 is with original tubes except a pair of Mullard NOS 12ax7. Not really a fair comparison seeing as the tubes in my 508 costs a pretty buck.

    The 508 is more alive, has more richness, a tighter bass, and really gives those beautiful voices a bigger place in the sound stage. This is a big deal for me.
    The 518 with these tubes is too laid back and bloaty after getting used to the 508.

    I don't like bright speakers either, but the Cornwalls are straight up my alley. Brightness has never bothered me with them.
    I recommend you get a listen in a moderately to good room before judging them too harshly. :D

    More thoughts soon, gotta run! :)
     
    IanL likes this.
  19. bugo403

    bugo403 New Member

    Location:
    israel
    replaced the preamp section tubes to NOS RCA 5691 Red Base, Black Plates + Sylvania JAN CHS 6SN7WGT 1950's, smaller in size but bigger in sound. very happy with the improvements.
    [​IMG]
     
    Last edited: Dec 13, 2017 at 3:33 PM
  20. adamaley

    adamaley Member

    Loving the pictures @valfy . I missed my UPS delivery yesterday, and I wasn't a happy camper. I'm busy all night today and tomorrow so won't get to listen much till Friday. Great info on tubes as well.
     
  21. adamaley

    adamaley Member

    Thanks for this. Any insight on the heavy hitters like the Elrogs or Takatsukis? The Elrogs tend to not work for every amp out there depending on specs, but the Takatsukis are known to be great as well.
     
  22. brody836

    brody836 New Member

    Location:
    Palmdale, CA
    Haven't read anything about the Elrogs or Takatsukis but I'll check 'em out.

    I'd like to pick up a Sylvania 6SN7WGTA black base pair. TubeAmpDoctor.com is about half the price of Upscale Audio, is this a "you get what you pay for"? FWIW I had good luck with the Psvanes from TubeAmpDoctor
     
  23. JeffC

    JeffC New Member

    Location:
    Catskill, NY
    Hello valfy, and welcome to the forum!
    There is some discussion of the NFB issue in posts # 317 thru 322 above.
    I look forward to learning more from your experiences!
     
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  24. adamaley

    adamaley Member

    Don't know if we are allowed to link to the 'gon here, but I saw a quad matched 6SN7 GTA there this morning for $167. No mention of black base, and no 'W' in the name, so don't know if that qualifies.

    Good old UPS had lost my package over the last two days. Finally got a call this morning to pick it up. Hopefully it's all in one piece.
     
  25. JeffC

    JeffC New Member

    Location:
    Catskill, NY
    Have you picked up the 508IA?
    I've very much enjoyed the Psvane WE replica 300Bs in this amp. Coupled with an especially quiet Tung Sol 6SU7GTY input tube, they really managed to eliminate the last bit of tube and transformer noise through my 15" Tannoy speakers.
    I'd love to try the Elrogs or Takatsukis.
    I see that Grant Fidelity is now offering the top capped Psvane 805T tubes for use with this amplifier. Each order also includes lead wires with a top cap receptacle for use with the LM 508IA:
    805-T (Capped type, Pair)
     
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