New Line Magnetic 508ia Integrated Amp

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

  1. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    As for the safe discharge, the main capacitors each has a discharge resistor piggy back onto it. From calculation, after 60 mins, they will be discharged to less than a AA battery, completely safe.

    [​IMG]
     
  2. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    Very helpful! So as I mentioned earlier, after the amp is warmed up ~1 hr any mechanical hum nearly disappears completely so likely from parts expansion. After checking 3 or 4 of the bolts I don't think I will have the need to open the bottom again but it is nice to know how to avoid killing myself if I do! I also understand that simple break-in of the amp may also be beneficial for this issue.

    Another question which could probably be a thread on it's own: Has anyone with a Line Magnetic amp noticed their amp sounds best when line voltage is measuring nearly dead on 120V (US obviously) and AC line frequency is measuring exactly 60 Hz? I've been monitoring my dedicated audio circuit today and notice quite a bit of variability between 117-122 v with best sound at 120. It makes me wonder if there would be a benefit to picking up an AC regenerator like from PS Audio. Has anyone else considered this on gone this route with results to share - positive or negative?
     
  3. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    I tried plugging the 508IA into my ancient PSAudio P300. It draw so much power the protection circuit was tripped almost immediately. :oops:

    You'd have to spend a fair amount of money to get something to power the 508IA with enough headroom.
     
  4. Mok

    Mok Forum Resident

    Location:
    Brooklyn, NY
    I have a 518ia which should be a bit less of a power draw. It's plugged into my PS Audio P12 regenerator, which supplies 120V and pulls down the AC line distortion. The amp pulls about 50% of the available current from the P12, and when I have it running with the rest of my components (Mac Mini, PS Audio Directstream DAC, etc.) I get up to about 65% total draw. I should probably have a bigger regenerator, but I've never had an issue with this, and I never see the draw go above 70%, so there's enough power headroom there for my small listening environment and this amp.

    I definitely noticed lower noise throughout the system when running the components through the P12. I'm sure there's a bit more refinement to the soundstage and perceived depth as well - I stopped trying to quantify all the benefits of what I've done to the system once it occurred to me how enjoyable the whole thing sounds. Yes, these things all have effect for sure, and the main reason why I added the components I have together is to maximize the potential for the listening experience.
     
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  5. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    Thanks @Mok . Exactly the kind of feedback I was looking for. And @jmpsmash - yeah, I wouldn't imagine the P300 would come close to handling the load. The P12 seems like the minimum starting point for the 805 since it does put out 1250 watts and the 805 I believe has a 400 watt draw.

    My system always sounds better after 10pm and I'm sure I could benefit from something like this. It's just a matter of finances and priorities...like so much in this hobby ;-)
     
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  6. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    Considering the cost of a P12 I think I can do without a power regenerator. Afterall, I should really be focusing on work before 10pm, else how to pay for this expensive hobby. :D
     
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  7. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    So I rolled a pair of these 1940s NOS Sylvania VT-231 6SN7GT's today in the 805ia. Liking what I'm hearing so far. I was afraid I may be sacrificing some bass but I'd only say barely (compared to the CBS Hytrons that were in there) and in fact the sound is better balanced now across the range. Love what they do for the mids and highs and creating spaciousness. We'll see what the next 50 hrs brings.

    [​IMG]
     
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  8. Strat-Mangler

    Strat-Mangler Personal Survival Daily Record-Breaker

    Location:
    Toronto
    Yep. As we discussed, they do have a more airy sound. Glad you're enjoying them, bud! :righton:
     
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  9. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    They definitely do....the more I listen the more conflicted I become about that slight loss of low end foundation compared to the CBS tubes. Ha...tubes are such a game of give and take. I should have an RCA JAN CRC-5691 red base arriving in the next day or so we'll see what direction that takes the sound in the 6SL7 socket. Those Mullard 6SL7's are hard to come by and pricey but perhaps I'll stumble on one soon to try.
     
  10. Strat-Mangler

    Strat-Mangler Personal Survival Daily Record-Breaker

    Location:
    Toronto
    As I stated via PM, they are more bass-shy. The Ken-Rad are on the other extreme ; tons of bass, bass detail, bass slam aplenty, but rolled off on the highs, creamy on the mids, with less detail.

    The Mullard is definitely worth it. My personal experience with the RCA was that it was rather velvety, euphonic, but laid back to a degree that reminded me of 70s Marantz integrated amps. Basically, not as dynamic as the LM amps can be. Warm but not with a lot of detail, especially in the bass.

    Let us know your thoughts once you have the luxury of performing your own shootout.
     
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  11. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    @Strat-Mangler Thanks for your impressions on the RCA 5691's and well as Ken Rad 6SN7's. . Speaking of Ken Rad, have you tried the Ken Rad JAN CKR 6SL7GT/VT229?
     
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  12. Mok

    Mok Forum Resident

    Location:
    Brooklyn, NY
    Expensive, YES. Here's what path I took to get there. I was having some issues with noise in my system - chalk it up to noisy items (like a computer, cable modem, antenna, DVR, etc.) that were somewhat alleviated by getting a Jensen ISO-Max isolation transformer to put inline with the CATV line - something about a ground difference between the power ground in my apartment and what is legally obligated by the city, a separate path to ground for any CATV lines (so if cable gets hit by lightning it doesn't fry the in-house wiring). The isolation transformer lifts the CATV signal and stops that ground difference (ground loop) from dirtying up the common ground for my equipment. Problem (mostly) solved, for I think $60. In search of even lower noise, I looked at regeneration. I got a good deal on a second (or third) hand PowerPlant Premier from someone on Audiogon. $700 and I could see what it could do. What a great unit. Knocked the THD on my lines down. Normal running operation, it measured about 2.4% distortion on the sine wave. When I turn on the 518, this jumps up to 4.7%. I don't really know why, but I assume that this type of amplifier is a source of noise on the power line for anything else on the circuit. Learned something new! PPP got this distortion down to 0.3% on average. It is GREAT. But, the thing about the PPP is (and I assume all of these regenerators), it starts to go bad after a few years. Overheating, I hear audible clicking of the regen circuit coming in and out (not in audio so much but physical clicking from the unit). I love what it does but the thing is on its last legs. PS Audio was running a deal where they would give you 100% of the original purchase price in exchange for a new unit. I think they know this stuff has a limited shelf life! I spent $700 for the used PPP, but got $1500 in exchange on PS's site. That combined with a temporarily on-sale holiday deal last year let me pull the trigger for a brand new P12 for $2800. I didn't really want to spend it, but I'm very happy I did. The P12 gives me better performance (THD is always 0.1% with or without the 518 on) and it's dead quiet in operation.

    I do not expect everyone has $5000 or more to spend on power. It is a *marginal* improvement item in most cases! But like I said, preserve the potential for the experience. Big bang items feel good when you buy them, like speakers, amps, DACs, phono cartridges. Then the other stuff like cables, power management - that stuff will never not feel weird for me to spend money on. But it all works a bit here and a bit there to get you somewhere you want to live for the rest of your lifeā€¦
     
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  13. Strat-Mangler

    Strat-Mangler Personal Survival Daily Record-Breaker

    Location:
    Toronto
    You're welcome. Unfortunately, no. The Mullard is terrific so not looking for anything else anymore.
     
    Last edited: Sep 1, 2020
  14. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    Small updates on the 508IA upgrades. I have completed the updates on the power supply side, and I am very happy with the result.

    Now that the foundation has been laid, I am moving onto the signal path. I had previously upgraded the coupling capacitors to Miflex. I am not really happy with the sound. It sound dark and laid back, and lacking some airiness. I have acquired some Mundorf Silver Gold Oil and Jupiter Copper to replace those, along with better resistors and cathode bypass capacitors. Since the caps need hours of burn in, I am pre-burning them in another rig right now and will install them in the 508IA in a week or two.

    [​IMG]
     
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  15. tIANcI

    tIANcI Active Member

    Location:
    Malaysia
    You gotta give us a list of upgrades to look into. Dang ... you are really hard working. Wrestling with that 42 kg behemoth
     
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  16. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    This message from over a year ago describes some symptoms I've been wrestling with the past day with my new LM805. I fortunately have a few good tools to do some diagnostics and I wanted to pick the brain of this group as far as the best permanent fix is concerned.

    I was getting some 60hz hum which was most pronounced when using the pre in and connecting my VAC linestage. I noticed the hum was a bit reduced when I used my Isotek EVO3 Syncro (sine wave restorer) device on the amp AC line. It wasn't effective at all using it on other components, including the preamp. I also noticed that hum was reduced marginally when I plugged the preamp directly into the wall receptacle instead of my Niagara 1200 conditioner.

    All of my components share the same receptacle so I wasn't thinking ground loop was likely an issue. But just for kicks I dug out my Hum X and connected it to the preamp - no change in hum. Then I plugged the Hum X into the LM805 AC line. Presto! The hum was eradicated 100% just like magic. So what's going on here? Is this a permanent fix? I measured amperage draw on the LM805 to make sure it wasn't going to exceed the 6A stated limit on the Hum X. The LM805 didn't draw more than 4.40A even while really cranking some music.

    So is this diagnostic of a problem I could fix another way or would you guys recommend I apply the Hum X as the final fix? It doesn't feel like an "audiophile" solution. Can an integrated amp have a ground loop issue on its own or does it need to be interacting with some other component sharing the same line? I would assume any interaction would have to be either with my preamp or crazy as it may sound, with my Niagara 1200. I have the Hum X plugged in between the amp AC line and my Niagara 1200. Anyone else ever have the same issue with this amp? I just provided this same info to my dealer so we will see what he thinks. Looking at this PS Audio article it seems that they feel Hum X is a safe remedy when effective How To Find and Fix Hum Extended

    Thoughts are appreciated.
     
    Last edited: Sep 4, 2020
  17. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    did you try to get rid of the Niagara all together? and then just plug the VAC and LM805 into the same outlet. or as close together as you can.
     
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  18. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    Great minds think alike! I actually just finished doing that and have FINALLY figured this out. Ground loops are tricky with so many possible combinations that create a completed loop.

    1) I eliminated the Niagara completely and plugged just the VAC and the LM805 into a power strip - hum was produced.
    2) Next I lifted the ground on the VAC using the Hum X - hum was completely eliminated.

    So we found the culprit...but didn't I "essentially" try this before? Nope...because the Niagara was keeping the loop completed. As it turns out my DAC kept the ground loop intact with its singled ended connectors going into the VAC even when the VAC was plugged into the Niagara via the Hum X. I never thought about unplugging the DAC from the Niagara while lifting the ground on the VAC before.

    So I then confirmed that as long as I lift the ground on the VAC and isolate the DAC from the VAC by not plugging them both into the Niagara the hum is fully eliminated. So I guess that will be my long term solution - using the Hum X on the VAC and making sure the DAC and VAC aren't both on the same strip/conditioner as the LM805.

    I suspect that if I had balanced connectors on my DAC the use of everything on th Niagara wouldn't be an issue. Alas my Lampi DAC is single-ended only. Gives me ideas for an upgrade down the road but the workaround is very doable for now.

    Ok, now I can sleep!
     
    Last edited: Sep 5, 2020
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  19. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    So now that I have my ground loop bug worked out I took the opportunity this morning to compare the LM805ia onboard linestage vs the VAC Ren MK5 linestage (using the "pre in" switch). It wasn't even close, the sound is substantially better using the VAC linestage - soundstage, dynamics, and details. With the said, if I didn't have a separate linestage I'd still love the sound of the LM805ia on it's own.

    btw: One follow-up on the ground loop. I figured out this morning I can have the VAC and the DAC both plugged into the Niagara at the same time but I need to use the Hum X on the VAC and the LM805 can't be also plugged into the Niagara (which actually may be better for sonics - I was using it mainly for protection).
     
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  20. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    Has anyone tried these Psvane CV181-TII (6SN7) tubes in their 508/805?

    [​IMG]
     
  21. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    I have a pair. I had them installed in some other amps and I haven't tried then on the 508 until you inquired.

    I swapped them in place of the Sylvania VT231, so any comparison would be because my ears have been tuned to the Sylvania VT229+VT231 sound. Which are a bit to the brighter aggressive side.

    I did some 30 mins of listening and they do sound nice. Overall presentation it is slightly warmer. The sound is detailed, instrument separation and texture is good. High is a bit recessed compared to the Sylvania (which might be a good thing?). A bit more emphasis on the mid to low bass with good definition. However, also a tad bit slower, doesn't have enough slam. Sound stage is good but not vast (to get extremely deep and wide sound stage, you need the *real* CV181).

    Overall, it does most things really well, but nothing extremely so.

    I quite enjoyed it, it is a bit easier on the ear, but might need to balance it with something to fill in the top end.

    For the price, it is good value. Any good 6SN7 tube these days will be at least that.



    [​IMG]
     
    Last edited: Sep 5, 2020
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  22. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    Thanks for the reply and reflections from your experience. I ask because I just bought a matched pair still new in the box unopened from 2018 off USAM for $135. Seemed like a good deal and what the heck right? I should have them this week.

    We'll see how the compare to my CBS Hytrons that are paired with an RCA JAN CRC 5691.
    [​IMG]
    What 300B's are you using?
     
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  23. adamaley

    adamaley Forum Resident

    Interesting looking 300bs. What are they?
     
  24. jmpsmash

    jmpsmash Well-Known Member

    Location:
    Santa Clara, CA
    KR VV302B
     
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  25. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    What's your experience been @jmpsmash ? Is the LM sensitive to 300B rolling?
     

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