New Line Magnetic 508ia Integrated Amp

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

  1. IGD Positive

    IGD Positive Forum Resident

    Location:
    Inner groove
    This is interesting and potentially helpful for me. I've got a bit of hum and I thought I did everything to try to eliminate it but I did not try putting the LM-805IA on a different strip/conditioner from my DAC and/or preamp. I'm not at home now but once I get home, I'm going to give that a go and see what happens. I have the LM-805IA, a Mytek DAC and a Linear Tube Audio preamp all going into an Audioquest Powerquest 3. Sounds like at the very least , I need to experiment with pulling the LM-805IA off of the Audioquest and see what that does.
     
  2. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    Yep, I felt kind of dumb not realizing that using the same power strip/conditioner could keep a ground loop intact because of the other components tethered via the preamp (despite having lifted the preamp ground). A good lesson for sure.
     
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  3. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    So my Psvane 6SN7's arrived today. Been listening for about 2 hrs. They sound much different than the NOS Sylvania and RCA VT-231's...not as much sparkle on the top end which is actually a good thing to my ears. They actually sound like a modern version of the CBS Hytrons that they replaced in the sockets. They are more "hifi" sounding, more dynamic, and quite clean...not as romantic as the NOS tubes. They are a nice change of pace for a while...almost like a adding a solid state element to the sound.

    They were brand new in sealed boxes with factory measurement sheets dated 2017 inside. I was a little worried because the tubes were a tad noisy as first but that noise disappeared completely with only 20 minutes of burn in. They seem to pair nicely with my RCA CRC-5691 (6SL7) in the middle.
    [​IMG]
     
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  4. AP1

    AP1 Member

    Location:
    TX

    I recently purchased LM-508ia, direct from China. It is 220V version, but inside it looks EXACTLY the same as your LM-805ia. It has same component types, inludes additional (comparing with older version) relay board. It looks like LM sells their amplifiers under TWO different model numbers: one for domestic and another for international markets. But physically they are the same.

    The only downside of buying China domestic model is that it requires 220V line power. I though that there will be an option to change that by swapping wires around power transformer, but looks like all relevant wiring is under transformer bell housing. I decided not to bother with removing it (and thus risking damage high gloss paint) and simply purchased a boost transformer. All together (amplifier, shipping from China, 1000W boost transformer) it came at 1/2 the price of international version from US based dealers.
     
  5. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    It can be done. And very simple. If you look inside your 220V one, I bet the wiring to the middle transformer looks like the right hand side. Just wire it to look like the left. Then you are all done.

    If it looks nothing like I posted, then don't touch it, that means they changed the transformer design since they made mine.

    [​IMG]
     
    Last edited: Sep 7, 2020
  6. AP1

    AP1 Member

    Location:
    TX
    I will check it out next time I open it. I just noticed that power transformer pin numbers do not match schematic I have. I left it alone and got a boost transfomer instead.

    So far the only change I did - replaced stock 300B tubes with a pair of Sofia Princess which I obtained long time ago and had no use. That made sound a bit more rounded reducing some mid range edginess. I also ordered Russian 1578 and 1579 tubes made in 1950s. When they arrive, I will check if they improve anything over tubes which came with the amp. I tried some modern 6SL7 I had on hands, but stock tubes in this amplifier were sounding better.
     
    Last edited: Sep 7, 2020
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  7. Strat-Mangler

    Strat-Mangler Personal Survival Daily Record-Breaker

    Location:
    Toronto
    Not exactly. There are two different models with different power transformers ; one with 110V and one with 220V. However, the 508IA and 805IA model numbers have nothing to do with this whatsoever. There are 2 versions of each of these models.
     
  8. AP1

    AP1 Member

    Location:
    TX
    From what I could find so far: there are two versions - one for domestic market (220V only), another for international market (can be 240V or 120V). When I look at picture of 805 model internals posted above, I see EXACTLY my 508 model. Both were purchased recently. That allows me to make a conclusion about two modes with the only real difference in imprinting on transformer's cover. But that won't justify 100% markup from European and US dealers vs. mainland China sellers.
     
  9. Strat-Mangler

    Strat-Mangler Personal Survival Daily Record-Breaker

    Location:
    Toronto
    Let's try this again. The 508IA was released 4 years ago. There were two versions of that ; 110V and 220V.

    The 805IA was released recently ; there are 2 versions of that as well.

    The 508IA and 805IA are two different models which came out 4 years apart and both of these models have 2 versions. It's not that the 508IA is for the US and the 805IA is for the Chinese market or vice-versa.
     
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  10. AP1

    AP1 Member

    Location:
    TX
    The unit I bought was made in 2020. Many China based sellers do offer 508 model all over Internet, NONE of them sell 805 model. NONE of US and European dealers sell 508 model. And this is NOT only about that amplifier. All others from LM were recently rebadged for international markets.

    Anyway you can believe whatever, I only state what I observed with my admittedly narrow view.
     
  11. Pedro Guillemain

    Pedro Guillemain Well-Known Member

    Location:
    Argentina
    Well I have all of my system (but my subwoofers) plugged into my AQ Niagara 1200, wich feeds from a dedicated AC line passing through a Holton DC Blocker.

    I have several devices connected to the 1200:

    Ubiquity Router
    Uptone ER switch
    SOtM SMS Ultra Neo
    Audio GD DI-20 digital interface
    Audio GD M1 preamp
    Line Magnetic LM508 used as power amp

    I never had any considerably hum and it was reduced with AC conditioning, rolling valves and tightening a little bit the tranformers screws when I upgraded the internal parts of the LM508. Now I have to put my ear right next to the tweeters to hear a very very very small hum, almost not there at all.

    All of my system, but the subwoofers, share the same ground of course.

    I hope it helps.
     
  12. Strat-Mangler

    Strat-Mangler Personal Survival Daily Record-Breaker

    Location:
    Toronto
    No idea why this is the hill you want to die on, considering I bought my 508IA manufactured in 2017 which has a 220V power supply. The 805IA didn't exist until earlier this year. Essentially, I have proof you're factually wrong so very very strange that you want to cling onto your wholly wrong conclusion, 100%.

    I've established my credibility over a period of almost a decade on this board and know what I'm talking about, going so far as to alert other owners about a design flaw in the circuit. So I'll simply quote you right back to you ; believe whatever you want.
     
    Last edited: Sep 8, 2020
  13. Mok

    Mok Forum Resident

    Location:
    Brooklyn, NY
    What @Strat-Mangler is saying here is correct. Line Magnetic *famously* changed their model numbers recently.

    For example:

    What used to be the 508 is now the 805
    What used to be the 518 is now the 845
    What used to be the 219 is now the 845 Premium

    It's the sort of pattern that goes:
    What used to be the <weird number> is now the <more recognizable power tube number>

    If I'm wrong I'll eat my avatar, but I'm almost positive there was an announcement in this very forum somewhere when this happened, and it might even have been in this thread.
     
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  14. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    Pretty much what was said by S-M and Mok. Here are a bit more details to the "evolution". Please correct me if I am wrong.

    508IA, initially launched in 2016/2017.
    508IA, somewhere 2019/2020, has been "improved" to adding a new timer to avoid cap blowing up. Around the same time, 805IA shows up. Both 2020 508IA and 805IA look identical, externally and internally.
    805IA, also has the same improvements. In addition, in the EU site, it claims 805IA has more premium components like Mundorf cap. However, we failed to find them from user photos. However, I do see some differences in how the power transformer is wired, and AP1 noticed the transformer pin numbers different than the schematic. The pin numbers in my 2017 508IA (mostly) matches the schematic. So perhaps they did change the power transformer.

    Moreoever, it *could* be the EU version has better caps. But we don't have any confirmation.

    508IA in both voltages has been sold in all countries. 805IA has been in US/EU since release (in both voltages), but China still has 508IA. It could be a slow phasing out. Or maybe they made a bunch of 508IA printed face plates they want to get rid of them. who knows.

    And to complicate it further, there is a Singapore version, which some dude has swapped out some internal components with boutique ones. Quite secretive what they are.

    And of course soon there will be a jmpsmash version, also with boutique parts. I will publish the parts list here (no secret here) once those caps goes through 250 hours of burn-in and I am happy with the sound. :)
     
    Last edited: Sep 8, 2020
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  15. tIANcI

    tIANcI Active Member

    Location:
    Malaysia
    jmp - it’s no secret. Just get one and open her up!
     
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  16. adamaley

    adamaley Forum Resident

  17. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
  18. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    These showed up. :D Been too busy to spend any quality time with them. Maybe this weekend.

    [​IMG]
     
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  19. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    Looking forward to your review!
     
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  20. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    Quite thoroughy reviewed by other reputable members already, so I don't know how much value mine would add. Still, I will post my thoughts after some burning in.
     
    Last edited: Sep 11, 2020
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  21. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    Ah. Were the reviews of these 805 tubes posted on this thread? I will need to do a search.
     
  22. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    I don't even know how long it will take to burn in a 805 tube. I hope it is not 200 hours again. :cussing:
     
  23. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    @Strat-Mangler There's a guy on eBay selling a few of these. I made him an offer last night that he accepted. Looking forward to dropping it in.

    [​IMG]
     
  24. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    I spent most of this afternoon playing around with caps. In the 508IA/805IA there are 2 pairs of (de)coupling caps. One pair that goes from the 6SL7 to the 6SN7, another pair that goes from the 6SN7 to the 300B. The signal path travels through these so they are vital to the sonic of the amp.

    I previously had 2 pairs of Miflex KCPU installed in this location. While they were better than the factory caps, I never really like the sonic signature. They have good bass and clarity, but the overall tone is to the dark and laid back side. I had them in the 508IA for quite a few months, but never bothered to changed them until recently.

    I had planned to replace them with a pair of Mundorf MCap Supreme Silver Gold Oil caps. They are highly rated and not *too* expensive. And while I am at it, I borrowed another pair of Jupiter Copper Foil from my 518IA. I burned them in for more than 250 hours in my tube dac, running around the clock for the past 11 days.

    I previously have upgraded the power supply side, described in an earlier post. I recommend doing that first. Firstly it is more cost effective, and fundamentally, the power supply is the foundation of an amplifier, without a good power supply, it doesn't matter how good the rest of the component is, any upgrade to the main signal path will be bottlenecked and any minute changes cannot be clearly heard.

    So since I need 4x caps but I only have 2 Jupiter and 4 Mundorf, I first did the experiment to put the Jupiter between 6SL7 and 6SN7 and the Mundorf between 6SN7 and 300B. It sounded horrible. The lush sound of the 508IA is gone. There was lacking in bass, instrument texture were gone., some instrument so muted it was like a completely different amp. There was no life in the music anymore. I left it on for more than 30mins in case it needed warm up. It didn't help.

    I couldn't bear it. So I decided to put back one pair of the Milflex in order to find out which caps were screwing up the sound. I decided to take out the Mundorf first. Leaving the Jupiter between 6SL7/6SN7, and restored the Milfex between 6SN7/300B. And suddenly it was a WOW. The Jupiter is so so much better. The previous laid back and dark sound is gone. Out come a bunch of clarity, speed, and lively top end that is clear but not harsh. Texture from violin are clear, solo voices has a better realism. There is also an improvement in pace, each drum hit is more impactful. During complex symphonic passages, instruments can be heard more clearly. There are just so much improvement across the board.

    Now I have to buy another pair of Jupiter, and money spent on the Mundorf was wasted.

    So if anyone want to, forget about Mundorf. I have totally lost faith in Mundorf now. Spend the extra money and get some Jupiter Copper caps. But I still recommend upgrading the power supply first.

    [​IMG]
     
    Last edited: Sep 13, 2020
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  25. adamaley

    adamaley Forum Resident

    Waiting for you to share your complete parts list with where they go in the schematics.
     
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