1. Time for some upgrades in server hardware and software to enhance security and take AK to the next level. Please contribute what you can to sales@audiokarma.org at PayPal.com - Thanks from the AK Team
    Dismiss Notice

MC275 with LaScala : biwire on different taps possible?

Discussion in 'McIntosh Audio' started by jlopez, Jan 8, 2014.

  1. jlopez

    jlopez New Member

    Messages:
    9
    Hi all,
    I am new to this forum, and last year I was able to have a good deal where I could trade in my MA6300 for a C220/MC275 combo :D
    I am seriously considering buying the Klipsch LaScala II - I will hear them in a few days from now, but can't stop thinking/hoping that it would sound great.

    I have been reading almost every review ever written about the lascala and found that the mid/high operates around 3.6Ohm, and the low frequencies on 8Ohm.

    Now the following might by a dumb question, but here goes:
    can you biwire the speakers using the same Common for the med/hig and bass, and use the 4Ohm tap for the med/high and the 8Ohm tap for the bass? Unless positively sure I am not trying this out, don't want to have anythin happen to my MC275.

    All help and feedback is welcome ! :thmbsp:
    many thanks, Juan
     

     

    Please register to disable this ad.

  2. drknstrmyknight

    drknstrmyknight AK Subscriber Subscriber

    Messages:
    5,529
    Location:
    Mount Clemens, MI
    Read about autoformers, and use the 8 ohm tap.
    No doubt it would be great combination.
     
  3. 62caddy

    62caddy Trust but verify Subscriber

    Messages:
    9,466
    Location:
    NEPA
    I seriously doubt you'll ever have a problem. Odds are you'll be running less than 1 watt 99% the time; with perhaps a 5 watt at peaks. Secondly, McIntosh output transformers are about as robust as any and well able to deal with periodic impedance dips with ease.

    Agreed with dsn - use the 8 ohm tap.

    Welcome to AK! :wave:
     
  4. william.keith

    william.keith Super Member

    Messages:
    1,307
    McIntsoh and Klipsch is a classic match. Output transformers (autoformers) easily handle any swings in speaker impedance. White paper by Sidney Corderman explains this in detail.
     
  5. 62caddy

    62caddy Trust but verify Subscriber

    Messages:
    9,466
    Location:
    NEPA
    Tube amps have output transformers while SS have "autoformers".

    I've never been able to understand the distinction, if any. Perhaps someone could explain in greater detail...
     
  6. william.keith

    william.keith Super Member

    Messages:
    1,307
    Charlie Randall refers to them interchangeably. Always assumed they accomplish the same essential purpose. Either way, I have the best of both worlds.
     
    Last edited: Jan 8, 2014

     

    Please register to disable this ad.

  7. jlopez

    jlopez New Member

    Messages:
    9
    Thanks all for the replies, really appreciated. Gives me more to read and learn, just need pointers, and I got some from the reply.:thmbsp: Was getting tired reading over and over again the same reviews ;-).

    So 8ohm taps it is. Any suggestion to do biwiring instead of classic 1 wire as per the method mentioned above? As the LaScalaII permits biwiring.
    (But it will be more costly, so not directly an option if there is little gain there - as the LaScala is already a big stretch for me, even with the current offer I got on them - live in Europe)

    Regarding the efficiency and the available 75W/ch on the MC275: this still worries me a bit, in the sense the MC might not be 'delivering' in the power range where it might excel most (I guess the amplifier does not work equally superb over the whole power output range). So losing some of the MC275 magic due to the high efficiency of the speakers perhaps...:scratch2:

    Anyhow, I am glad to be part of the Mac family - and can't wait to add Klipsch to that. The American way I guess ? :D Still need to learn how it all works though, which will only make it more great

    cheers,
    Juan
     
  8. 62caddy

    62caddy Trust but verify Subscriber

    Messages:
    9,466
    Location:
    NEPA
    Interesting question - but no, there's nothing you'll be missing simply due to the amp not "stretching its legs" as it were.

    In regards to bi amping - you're talking surgery, extra amplification devices and increased overall complexity - for dubious sonic improvement - in this application IMHO.

    Just hook up and enjoy! :music:
     
    Last edited: Jan 8, 2014
  9. twiiii

    twiiii Addicted Member

    Messages:
    6,226
    Location:
    west Texas
    First of all if you buy La Scalas you will be sacrificing the bottom 1 to 1 and 1/3 octaves of the frequency spectrum, that you will always be trying to make up for by changing other components or adding sub woofers that don't match up. You'd be much better off with pair of Cornerhorns or Cornwalls.

    At 105 db 1 meter 1 watt sensitivity and with the average person listening at 85 to 90 db the power required is 1/10 to 1/30 of a watt. Figuring in 10 db peaks that means 1 watt of power. So don't worry about a perceived mismatch.

    Now if you try to bi-wire using different taps you are now compromising the amp. We used to run the classic three channel Klipsch set up off one 275 using the 4 ohm taps in series for the center and the 8 ohm taps for L&R Kornerhorn. When hooked up this way the power available wasn't 190 watts the maxoutput of the 275 divided by 3 but closer to 45 watts each or 135. I have no idea what the bi-wiring sum would be but it would be certainly less. After the three speaker hook up with a few customers we went back and installed a center MC75 and the performance of the system was more satisfactory.

    There are things about Autoformers that in my mind are different from transformers. First the ratio between the input winding and the output windings is much lower with autoformers. Meaning there are less compromises in performance. Second usually one side of the output winding is tied to ground or common with an autoformer. So you can only tie the channels together in the parallel mode for higher wattage output monaural mode. Where with transformers you can tie the windings in series to drive higher impedances when the amps are used for 70.7 volt commercial applications. Now the Quad balanced amps that are totally balanced may have autoformers where the output windingss are segregated from common, I don't know. In any case its the execution of the design that is more important than whether the autoformer is balanced or not.
     
  10. drknstrmyknight

    drknstrmyknight AK Subscriber Subscriber

    Messages:
    5,529
    Location:
    Mount Clemens, MI
    Please!
    I'm so tired of listening to people who focus on the LF fall off on LaScalas...
    If house and techno are your bread and butter, go for pro audio components.
    If music is your goal, look at the graphs, compare them to the alternatives, come over and have a listen.
     
  11. kevzep

    kevzep Its all about the Music Subscriber

    On the quad balanced amps, there is a "centre" tap on the auto-formers which is common and then one side is driven by the negative amp, the other side is driven by the positive amp.
    I suspect as this is a "Floating bridged" type output section, the common may actually be floating and not ground as such, in fact I would put money on it. In fact I just measured my MC452 and the negative is not ground.....

    The basic function is the same, but an output transformer is a completely different animal than an Auto-former.
    The Auto-former is essentially a coil across the output of the amplifier with several taps which are the various output loadings.
    Your speaker load is physically connected to the output of the amplifier albeit through the coil.
    The Output transformer has a primary and secondary winding, the primary winding is connected to the output stage of the tube amp, and in a 275 this will actually include the extra winding for the unity coupled circuit.
    The secondary winding is the one which has the speaker output taps on, and one side of this will be the ground or negative and the other side will be the various taps available for the given loads for the amp...

    They are quite different from each-other and they are not to be confused if you are to understand how your amps works, and I would not be driving anything other than the specified load on a tube amp output.

    To the OP, what are you trying to achieve by "bi-wiring" these La'sacala's? Its probably not necessary and I doubt there's anything to gain with the amount of power we are talking about here....
    I agree with twiii, go for a speaker which is actually a more full range, the Lascalas only go down to about 40hz, you really are missing out a whole octave of bass with those...
     
    Last edited: Jan 8, 2014

     

    Please register to disable this ad.

  12. kevzep

    kevzep Its all about the Music Subscriber

    There's no need to get so defensive, the fall off around 40hz, thats at least an octave.....its not a criticism, its a fact...
    If you are happy missing out an octave, then that's cool, but don't shoot a guy down for stating a fact....
    Maybe the OP will listen to the lascalas' and decide he likes them, plenty of people do....
    It wont make any difference to your listening experience so it's all cool....
     
  13. william.keith

    william.keith Super Member

    Messages:
    1,307
    I think you are over-working the matter. Start enjoying the music.
     
    Last edited: Jan 8, 2014
  14. jlopez

    jlopez New Member

    Messages:
    9
    Oh boy - it makes my head spin even more :eek: but thanks for the replies, it is all very informative. But of course, in the end, it's all about the music, which is by itself subjective. So all feedback is welcome. I only wished I had more knowledge in the area of electronics, I find it very interesting. And it all started when I lighted up the C220/MC275 for the first time :), few months ago.

    The Khorns... yes, but that is way out of my reach here. They sell (no second hands to find here) new for 14K€. No can do. The Scala's for 4K€ (ex-demo).
    I need to hear them first though. I know I will be missing the bottom frequencies. But could be fixed with a sub (I still have a REL T5) - but I am totally ignorant in how one needs find a good companion to go with the lascala. I guess this is also yet another topic in itself...:D

    Or I could go back to the drawing board, and build the Khorns myself. I have the autocad drawings with metric system. Speaker units and Crossover: buy it (not build it). It's the wood assembly and finishing that is the tricking part. That would make the Khorn feasible. But...

    @kevzep: For the biwiring question, I was only considering the fact you have 8 and 4 ohm taps, and thought I could use both at once, 8ohm to feed the LF, 4ohm to feed mid/high - and this for the L/R speaker on the same MC275. But as told, it could be a stupid question not making any sense (from amp build perspective) aka: :screwy:

    Next week I will be listening to the lascala's with my amp, and I'll keep you posted about my impressions with them :smoke:. But keep all info coming, the more the better - certainly much appreciated over here !
     
  15. kevzep

    kevzep Its all about the Music Subscriber

    Well, at the end of the day you'll listen, and if you like what you hear, then you will make the move which makes you happy.....:thmbsp:

    I wouldn't be put off by the statement that its difficult to get subs to work with the Lascalas, its no more difficult than any other speaker, which is not that difficult at all....
     
  16. o0OBillO0o

    o0OBillO0o Active Member

    Messages:
    410
    I would use the same terminals but with matching extra wire lengths, if you want to bi wire for extra copper. Or just use a very good speaker wire with a decent American Wire Gauge (AWG).

    I love Klipsch Heritage speakers, you won't be disappointed in the "Music output dept."
     

     

    Please register to disable this ad.

  17. o0OBillO0o

    o0OBillO0o Active Member

    Messages:
    410
    The ones who don't have wives* that don't like their size or looks.

    *zero wife acceptance factor. Really, no wives own Klipsch Lascalas
     
  18. twiiii

    twiiii Addicted Member

    Messages:
    6,226
    Location:
    west Texas
    I have installed more la Scalas than you could imagine. In the birch wooden form, natural and in black and in the commercial split form in a road case look. They roll off at 60 to 55 hz if not in a corner. When suspended in the air they quit at about 75 HZ. I used them with MWM with 2 15" subs in a W woofer box from the Cinema Series and also MWM-s with single 15 inch woofer. All powered in groups of 4 by either a 2105, 2120, 2155, 2150, 7150 for the tops and multiples of 2105' 2200 2205 2250 2255 or 7300 for the sub. They sounded terrific that way.

    When placed in a home with a SW-15 sub by Klipsch or sub by some other Manufacturer the sound was never right. An infinite baffle sub just doesn't match a horn loaded La Scala, ever. We had one customer with a 3 channel La Scala system because he didn't have corners with a MWM-s that backed into his Garage behind his listening space. We crossed over the system around 70 HZ as I remember and the sound was great. I had to use a 24 db octave crossover coming off the center channel of a C-22 and 3 pair of 2505 amps. 1 amp mono for the sub and the other two for the 3 La Scalas, he liked meters and the tube sound of the C-22 as he felt the C-26 was to noisy, hard, and edgy and I had to agree. It was great sound and when he later added some MXR EQ's the system was 4 star system in my book. But for just a simple stereo system I much prefer the Cornwall. It has issues with higher crossover point for the woofer and the smaller midrange horn and it does have a smaller sweet spot for stereo listening. It has the flattest response and is less effected by room acoustics than the La Scala and Corner horn. So based on those issues and my experience in listening to 1000's of hours of La Scala, Corn walls, Cornerhorns and Hersey's in homes and commercial venues. I recommend a Cornwall. I've used cornwalls to suplement classical Guitar concerts with our local symphony as the sound from an A7 or JBL 2 way systems just couldn't cut the mustard. In fact if I had to replace my 6,0 HT system today I would have 2 Corner Horns, with a La Scala in the middle 2 herseys for the sides and 2 cornwalls for the rear. New klipsch stuff doesn't impress me. In fact i much prefer the older klipsch with the EV tweeter and Atlas driver with the less severe crossover networks. I means the speakers are only rated for around 40 watts that way, but that's what I would have if I had my choice. I apologize If I rubbed your feathers the wrong way.
     
  19. damacman

    damacman Blown and Injected Subscriber

    Messages:
    8,612
    Location:
    Gilbert, AZ
    twiii - MWM?
     
  20. o0OBillO0o

    o0OBillO0o Active Member

    Messages:
    410
    Good Post!


    Why not 7 Cornwalls if your recommendation is a Cornwall?

    I used a similar set-up but had LaScala's as rears.

    Thread Hijack: Regarding subs, you are spot on! No sub works with these heritage speakers and I can't place the phenomenon. For me, the Klipschorns have a MEN220 to time align the top with the bottom bass horn. It works and sounds amazing. I have a pair of JL Audio F113 subs and they cannot integrate with this set-up. I managed to get it close enough by , using my HT processors delay, time aligning the subs with the stereo pair but it is not a total solution. I've planned this summer to have a separate HT and Stereo system, because I watch movies just as much as I listen to music. I am still on the speaker/amp hunt for that. PM offline if you want to talk more.
     

Share This Page