Line Magnetic LM-88IA Integrated Vacuum Tube Amplifier

Discussion in 'Audio Hardware' started by brownmagic, Jul 28, 2020.

  1. brownmagic

    brownmagic Active Member Thread Starter

    Hello All

    I am starting a new thread to share my experiences with this LM amp. I had taken advice from a lot of wise men of this forum and it surely helped me bag my first tube amp.

    For those looking at specs and other details of this amp, please hit the link below.égré-push-pull-kt88-2x42w-detail

    This is a continuation of my journey post the knowledge that I have gained from the below thread. If you are first time Tube Amp buyer, then I highly recommend that you follow the below thread. There are some very helpful people out there.

    Help with first integ. amp - Primaluna v. Rogue v. Line Magnetic v. McIntosh v. Naim

    So my amp was delivered in all its shining piano black glory ( it is also a dust magnet) last week. The dealer personally delivered the amp and he gave me a 15 min dos and donts.

    This tube amp has 0, 4, 8 and 16 ohm. I was educated ( in the above post) that the black speaker wire goes into the 0 ohm (ground) tap and then the red wire goes into a tap of your choice. I put into the 4 ohm tap because my speaker Elac Adante AF 61 was rated for 6 ohms. I am yet to experiment with other taps.

    The sound out of the box was not what I had in mind. I was not very concerned either because in the few years that I have had a decent system, I knew that things need to settle down. The dealer told me that he had about 5 hours of running he did on the amp since he had made some upgrades as well. He told me that it would take 50 hours for things to settle down. The first track I played right after the 30 second blinker stopped was from Tidal and it was Down in the Hole by John Cambell and while the vocals felt like they were coming from my house, it was very raw. This was right after the amp was turned on. My wife who has a sensitive ear told me that it was very raw and she described it like the singer was practising instead of performing. The bass was also wobbly. Within an hour, I felt that the sound was improving in the mid range. The highs were still quite sharp in some tracks but the signature of the trebble was more crisp than bright. I never felt that this could be a bright amp and I was right. I played all sorts of tracks. I tried some infected mushroom and I dont think this amp had any issues with mid bass. One of the things that I noticed was on the strings. The strings for the lack of a better word felt like they were played in my house. The decay was longer..not sure if that was a good thing or a bad thing but to my ears it was nice.

    After about 3 hours of listening, it was quite late in the night and I had the entire space for myself and I tried some Sinatra and it was very nice. I have no doubts that the amp will shine in the mid range, I need to find out how they settle down in the upper and lower registers.

    if any of you have any tips or suggestions that can help with my progression, please do share. I will share my findings as I discover this amp.
    Last edited: Jul 28, 2020
  2. GoldprintAudio

    GoldprintAudio Forum Resident

    Lexington, NC
    Took a quick look at your speakers. Looks like they are a 87db load with a 6 ohm nominal impedance. Elac suggests a minimum of 50 watts.

    To be totally honest, some of the harshness in the top end may be coming from the speaker load being a bit too much for the amp. (especially if you are running it in Triode mode)

    Are you listening at higher volumes? And are you running the amp in triode or ultra linear?

    Hopefully more break in hours will settle it down some. As a LM dealer, I can tell you that I typically do not find the LM-88 as very bright or forward in sound.
    SandAndGlass, brownmagic and Ontheone like this.
  3. brownmagic

    brownmagic Active Member Thread Starter

    Thanks @GoldprintAudio

    What I meant was , the vocals were forward like as if the singer is in your house. I meant this in a good way.

    It certainly is not bright. I had taken an Elac UB5 which is 85DB @ 4 ohm for the audition in a much bigger room and it was fine. Coming from a 300 watt solid state peachtree audio amp, I am certain that the watts rating on the LM88IA is not the same as a solid state amp. I do not know how tube amps count watts but I feel there is enough and more juice on tap. So I do not think the amp has any issues driving these. The loudest I have played it till now is 930 o clock and it gets very loud. I usually play it between 8 and 9 assuming 7 is like the starting point. There is a lot more left to turn on the knob (about 75%) I am running it in the fixed bias mode. I seemed to like the sound in the fixed mode better than the cathode biased mode but ive not really got to a point of doing a critical comparison.

    How do you differentiate both these modes? Is it safe to assume that more dynamic music will be better of in UL mode where as the slow ones should do well with Triode? Should I listen to Iron Maiden in UL mode but listen to Frank Sinatra in Triode? Is that a good analogy?

    The following were upgraded from stock by the dealer. I am not sure what these mean

    Furutec AC inlet
    Vishay Resistor
    Vishay Capacitors
    Kiwame Resistor
    Mundorf Oil Coupling Capacitors etc
    Mundorf Power Capacitors

    I do not use the stock power cable. I use a furute nano power cable with furutec connectors which is also brand new so they might need some run in too.
    Last edited: Jul 28, 2020
  4. DryWhiteToast

    DryWhiteToast Where's my Ativan

    Good Luck with your purchase!
    Read all the posts in your other thread.
    Take Care
    brownmagic likes this.
  5. IanL

    IanL Forum Resident

    Oneonta, NY USA
    That doesn’t matter. If 9:30 is loud, you probably can’t get much above 10:30 before it distorts. My speakers are 86/6 as well and 11 is about the top limit, and 9 is probably the lower limit (before music loses most of its vitality). It sounds great within this range, but it is limited because it is less power overall than your speakers would prefer.
    Strat-Mangler and brownmagic like this.
  6. brownmagic

    brownmagic Active Member Thread Starter

    Hey @IanL - Thanks for the pro tip. Luckily I cant play it any louder in my room and I think the range is pretty workable for me. I bought this amp keeping in mind that I might experiment with an easier to drive speaker in the future.
  7. IanL

    IanL Forum Resident

    Oneonta, NY USA
    Me too. But I do love my speakers. A big part of that is how flexible they have been. I've heard them with a number of amps now, and they manage to sound good with all of them, even the ones that are limited in their power.
    brownmagic and SandAndGlass like this.
  8. brownmagic

    brownmagic Active Member Thread Starter

    Update at 25 Hours

    The mid range has improved quite a bit. The vocals are sounding more natural and airy. The bass seems fine to my ears. I dont see them lacking compared to the solid state. Slow music sounds very good in Triode mode. I have been using Ultra linear for Rock music. when playing Dreams by Fleetwood Mac, the cymbals sounds are edgy/grainy. I noticed the same when there is a distorted electric guitar. The dealer and I have been exchanging notes and his advise is that I need to run it in for a longer time to see if this goes away. He said that more than the tubes, it is the capacitors that need to break in and according to him Mundorf capacitors take longer to settle.

    I also experimented with the taps and I feel that the 8 ohm tap seems to be an easier listen. The bias on 1 tube is slightly off so Ive just ordered a screw driver that is small enough to get through the bias adjustment slot.

    Input stage: 2x 6CL8A (Mullard) et 2x 12BH7 (Electro Harmonix)
    Power stage: 4x KT88 (JJ)

    I am not able to find much information about the 6CL8A tubes on the internet. Are these the tubes that are responsible for the sound signature? If I were to sweeten the treble, is this the one that should be rolled? I am going to probably get about 200 hours before I think about tube rolling but Ive been trying to understand what tubes do what and what happens when you roll any of them.

    Thanks again.

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