High Power Mono Amps

Discussion in 'Audio Hardware' started by Tony Plachy, Dec 29, 2018.

  1. Tony Plachy

    Tony Plachy Forum Resident Thread Starter

    Pleasantville, NY
    I now have a pair of Magico S7 speakers (Impedance: 4 Ohms, Sensitivity: 89 dB). I am driving them with a pair of c-j Premier 12 mono amps (140 W for 4 ohm speakers). The sound good with these all tube amps, but I know they can sound better with more power (the dealer played them for me with some 400W solid state amps that certainly made the bass sound better).

    I would like some recommendations on high power amps and any input you have on your personal use of high power amps. Thanks.
    LeeS likes this.
  2. Standingstones

    Standingstones Forum Resident

    South Central PA
    You might look at the Parasound JC5. It isn’t a mono block amp but it does give you 600W into 4 ohms.
    SandAndGlass likes this.
  3. pigman

    pigman Forum Resident

    Mcintosh MC2301.
    Chazz likes this.
  4. Chazz

    Chazz Music Addict

    Southeastern, US
    What is your budget?
  5. Chazz

    Chazz Music Addict

    Southeastern, US
    This is exactly where I was going but budget is going to matter because of the cost of a pr. of MC2301's
  6. GoldprintAudio

    GoldprintAudio Forum Resident

    Lexington, NC
    What's your budget and are you wanting tubes or solid state?
  7. Gibsonian

    Gibsonian Forum Resident

    Iowa, USA
    You heard what you needed to at the dealer.

    How about active bi amping and use SS on the bottom and your tubes on top?
    McLover, Mad shadows and MonkeyMan like this.
  8. pdxway

    pdxway Forum Resident

    Oregon, USA
    My local dealer is selling a pair used at $30K. Retail was $65K. ;)
    See Echo Audio | Dan D'Agostino Momentum M400

    " These are, by far, the best amplification we've ever heard"

    At least price wise kind of matches your $58K speakers.
    Last edited: Dec 29, 2018
    SandAndGlass likes this.
  9. DPM

    DPM Forum Resident

    Nevada, USA
    You may want to check out Hegel. They use Magico loudspeakers to voice their amps, and I'm using one H30 to power my Q3 towers. I've no complaints.

    Hegel Music Systems - H30
  10. F1nut

    F1nut Forum Resident

    The Mars Hotel
  11. davidb1

    davidb1 Forum Resident

    Atlanta, GA
  12. Ezd

    Ezd Forum Resident

    You have more experience then me regarding high-end audio, but here is my experience with similar specked speakers... I bought a pair of Chapman Audio T9's (4 ohm, 89db, rated for 75 - 350 wpc) from someone near me, they were driving the speakers with a Goldmund amp, I forget the model. That particular amp did not have enough power for those speakers and it was noticeable.
    I bought them, took them home and connected to a NAD c375 bee rated at 150 wpc. This amp exerted more control / authority over the music which was immediately noticeable. I enjoyed this combination for a few months but sensed the speakers had the capability to offer more and starting searching locally for a more powerful amp. My research and budget had me considering a second-hand B.A.T. amplifier when a pair of used solid state mono-blocks rated at 300 wpc appeared at a local audio store. I was unfamiliar with the brand VTE, but was offered a good price and return policy. Again, there was a very noticeable improvement in bass and authority over the speakers.
    I have been very please with this combination...
    Currently I am exploring the sound of low-wattage tube amp and high-efficiency speakers... I would like to hear a pair of Magico speakers.
    SandAndGlass likes this.
  13. Black Elk

    Black Elk Music Lover

    Bay Area, U.S.A.
    All the best audio systems I have heard have had one thing in common: high power solid-state amplifiers. The two brands with which I have had the most experience are:

    Pass Labs

    I have used the Pass X-600 monoblocks to drive a variety of speakers (many considered difficult loads), always with stellar results. The late, great mastering engineer Denny Purcell used to use the X-1000, which Pass no longer makes! I would have a set of X-600s in my home right now but for one very important caveat: heat. The amps. idle at around 600 W, so that's 1.2 kW in a stereo system (3 kW in a M-ch system), and that heats up a room. Their less powerful pure Class A amps are the same, but the X-600 will still give you about 100 W in Class A before switching to A/B. So, only consider if you have airco or another way of dealing with the heat.

    As I live in California, and do not have airco, I opted to buy 400 W Classe monoblocks for driving my B&W 802s. The Classes are excellent, but the Pass has that little something extra. I think the Classes use a form of plateau-biasing (like Krell), so they do not heat up in the same way as the Pass amps in idle. Sadly, Classe is no longer in business.

    I have also used Ayre amps in a few systems, and they are very low-noise and very musical.

    Of course, perhaps the most famous name in high-power amps is Krell. I have not always enjoyed my exposure to their products, but I think they have gotten better lately, or maybe someone was doing better system matching. They should certainly be on your shortlist.

    Not as common as the above, but certainly worth consideration (if you have the budget) is Spectral. Often paired with Wilson speakers.

    If you are open to digital amps, you could consider the Mola-Mola Kaluga monoblocks. Everything I have heard that has been designed by Bruno Putzeys has been excellent.

    I have not heard their monoblocks, but I was very impressed with darTZeel's integrated amplifiers. Their monoblock will give you 500 W RMS into 8 ohms!

    There are a lot more companies out there, some with prices going to the stratospheric, but I think that is enough suggestions from me.
  14. Tony Plachy

    Tony Plachy Forum Resident Thread Starter

    Pleasantville, NY
    This was the one draw back to the S7's, they cannot be bi-amped, single input only.
  15. Gibsonian

    Gibsonian Forum Resident

    Iowa, USA
    Any speaker with at least a woofer and a tweeter can be biamped. It would take a little modification however.
  16. avanti1960

    avanti1960 Forum Resident

    Chicago metro, USA
    heard your speakers with these and a hybrid preamp from the same manufacturer- absolutely amazing......
    McIntosh MC1.2KW Amplifier
  17. Tony Plachy

    Tony Plachy Forum Resident Thread Starter

    Pleasantville, NY
    To answer some of the questions and bring up some additional information here is some more data:

    1. I would like to keep the budget in the ~ $30K range.

    2. I am leaning towards SS amps (or hybrid amps with tube input and SS output) even though I currently use all tubes.

    3. Because the speakers are 4 ohms any good SS amp that is rated at something like 400W into 8 ohms will produce 800W into 4 ohms. No amp is 100% efficient and most are lucky if they are more than 50 % efficient. That means to get 800W (even for only a short period of time) the amp needs to be feed something like 1600W. My two c-j P12's (140W each) draw about 450 W when running. Unfortunately they are powered by one 15 A non-dedicated circuit. (My house was built in 1973 and not wired for a high performance audio system.) I cannot use that line to power two amps that are drawing 1600 W each. I am going to get an electrician as soon as I can to get an estimate of what it will cost to run two dedicated 20 A lines. (I already know enough about electrical wiring that this is not going to be easy to do for several reasons.)
  18. Tony Plachy

    Tony Plachy Forum Resident Thread Starter

    Pleasantville, NY
    Wow, those are beautiful and must be very efficient because I checked and the only require about 1500 W input to produce 1200 W output. I like that even though they are SS they have transformer lugs to match the amp to the speakers. What hybrid preamp did they use?
  19. avanti1960

    avanti1960 Forum Resident

    Chicago metro, USA
    C1100. They also had a Mac transport and DAC. Sounded so transparent yet powerful- incredible.
  20. toddrhodes

    toddrhodes Forum Resident

    South Bend, IN
    At that budget and just based on some comments from a YT channel I frequent, but cannot afford to mirror, the JRDG 625, two of them in mono, would be in your budget range (the listed price below isn't the final price, I believe) and should do any passive box of speakers justice.

    Jeff Rowland Design Group 625 S-2 Stereo Power amplifier
  21. Mike from NYC

    Mike from NYC Forum Resident

    Surprise, AZ
    Bel Canto REF 600.

    I have them and they sound awesome and every reviewer praised them which is why I bought them. With my Revels they sound 'tube like' and offer a spacious sound stage - 3D like with many recordings. At 6,000 a pair you'd be hard pressed to find a better deal. And being Class D they don't build up any heat and are very 'environmental'. Balanced and single ended inputs. Very tight bass with a high slew rate.

    600W into 4 ohms!!!!!!!!
    timind and F1nut like this.
  22. Tullman

    Tullman I prefer analog

    Boston MA
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  23. Mike-48

    Mike-48 Forum Resident

    Portland, Oregon
    I have heard amps from these firms that have impressed me a lot:

    Pass Labs
    Bryston (28B3)
    Bel Canto

    The Pass have liquid midrange sound -- maybe a tiny bit more beautiful than reality (in the same way that ECM recordings can be).
    The newest Brystons sound quite liquid, with very low noise floor.
    The Classe models are unflappable, but they have fans, which can be audible in very quiet rooms.
    The Bel Canto was heard at a friend's house. The overall sound was outstanding, but I can't say how much was due to the amp. It surely was not the limiting factor.

    That is not to say that other manufacturers' amps might not be comparable. At the high level of your system, there's no substitute for listening at home.

    Frost likes this.
  24. FLEMKE

    FLEMKE Forum Resident

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  25. jeffmackwood

    jeffmackwood Forum Resident

    Some personal opinions / observations...

    Regarding the underlined quotation: I suspect there are lots of "good" amps out there that do not double their output power when facing half the impedance. Especially if we're talking continuous, rather than peak, capabilities.

    Regarding all the bits about efficiency and power draw: most "good" power amps have sufficient capacitance capability (call it reserve power) that they can handle higher output demands (especially "for only a short period of time") without overloading the circuit to which they are connected. Unless feeding very inefficient speakers, that are trying to fill a very large room with very high sound levels, most amps operate at somewhat modest "continuous" power levels in normal operation and rely on their peak output capabilities (where all that reserve power comes into play) to keep things musical / not go into clipping during the louder / more dynamic passages. (But yes, things can always be cranked up way beyond reasonable levels.)

    In my own main HT, where there is considerable output power available from several power amps, I have never had an issue with overdrawing the circuit even at high levels. My biggest concern is the ability of the circuit to handle the instantaneous demand for power when all of the amps are switched on simultaneously, and their respective capacitors are gasping for power to become charged up. There can be a momentary "sag" when that happens, but the breaker has never tripped.


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