MC152 and a few other questions

Discussion in 'McIntosh Audio' started by mg16listener, Feb 11, 2018.

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  1. mg16listener

    mg16listener Member

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    Hello -

    After many years of messing around with a few different vendors tube amps, I have decided to move back to solid state. While I have enjoyed tube rolling and other aspects of the tube experience they have turned out to be more unreliable than expected.

    I have a new MC152 arriving this week via my local dealer. I also have a few other pieces of McIntosh gear that include a D150 and a MCT450. The D150 could grow up to be a D1100.

    Anyway my questions are:

    1. I know this question has been debated many times. Would you leave the MC152 on 24/7 and turn the meters off when not using them or simply turn it on when ready to use it. The amp will be used daily for several hours each day.

    2. If you were to power it on and off would you allow the D150 to send a power on signal to the amp?

    3. Same power question for D150. I have been leaving it on but would consider turning on and off if there is a group consensus as to which is best.

    4. I will turn the MCT450 on and off as needed but the remotes of the D150 / MCT450 are not the best. Is there a way to have the D150 remote control all the functions on the MCT450. I know there is a data cable but not sure if this is the correct way based on what I read in the manual

    5. My speakers are nominal 4 ohms / 88db sensitivity. The obvious thing to do is use the 4 ohm taps. Any thoughts on this?


    Thanks for the insights -
     

     

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  2. techguy0192

    techguy0192 AK Subscriber Subscriber

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    1) No. As an owner of an MC152, warm up time wasn't a problem. I have personally never found leaving gear on all the time to be beneficial in terms of performance. A lot go Mac gear does not have LED for lighting; therefore, most owners don't leave equipment on 24/7.

    2) Sure. That's an included feature.

    3) See the reply to answer #1.

    4) The DIN jack is for audio in from the transport.

    5) Try the 4 ohm tap. But don't be afraid to try the 8 ohm taps. It will not hurt anything. Let your ears be the judge as to which sounds best.
     
  3. Archguy

    Archguy Official Roiurama Factory Rep Subscriber

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    Good advice from techguy. I turn everything off when I go to sleep, however my EE buddy in college left his SS equipment on all the time. It's really no big deal imho. Mainly I'm just chiming in to congratulate you on your new amp. It's a good solid piece and you'll love it.
     
  4. Mamrak1

    Mamrak1 AK Subscriber Subscriber

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    I have the MC152, it is a good choice. The power does not need to be on constantly. I hear no differences after the amp has warmed up. Try and use a 12 volt trigger cable between the amp and preamp. It’s one less step in turning everything on manually.
     
  5. ron-c

    ron-c AK Subscriber Subscriber

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    The data cable will allow the preamp remote to control basic transport function on a Mc CD player.
    Ron-C
     
  6. ddude003

    ddude003 New Member

    I have had a MC152 for about two years... It is a very nice piece... I turn it on in the morning and off at night or when I leave the house... It only takes a few minutes to warm up and sound its best... I trigger mine on and off from a pre/pro... As techguy said, try the 4 and 8 ohm speaker connectors and let your ears decide what you like... I run my MartinLogan ESLs on 8 ohms... The autoformers will make it right...

    Congratulations on your new amp...
     
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  7. mg16listener

    mg16listener Member

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    Thanks for the replies everyone. Looking forward to getting the amp.
     
  8. twiiii

    twiiii Addicted Member

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    With Martin logan speakers dropping down to 1 ohm or less in the top octave you really need an amplifier such as a MC 7200 which was designed to handle 1 ohm loads requiring lots of current and yet still supply the required voltage over the rest of the spectrum. Whats going to happen if the signal at 10 KHZ is 20 volts, That is 400 WATTS, way beyond a MC 152, while at 1 kHz with an 8 ohms load thats only 50 watts, no problem. A 7200 can put out 880 peak watts across 1 ohm, so you have a safety factor of over 3 db with a 1 ohm load while you are over 6 db short with the MC 152. How many db down are you going to be? why none until your 152 runs out of current and the power guard turns on reducing the signal till the current catches up. The possibility is easily over 6 db, and if the power guard pulls the spectrum down that much you will surely hear a change that will definitly play games with the sonic presentation.

    Now you know why Mac has introduced the MC 611 amp with that extra current capability. To regain the extra current capability the MC 501 had. The 7200 was a special amp designed to answer a special calling in the 80's. And you have that speaker that calls for massive current. But like other Mac amps that put out lots of power you had better have that 7200 on its own private 20 amps circuit. Its not as quiet as your 152 and the distortion isn't quite as low but it was designed to handle severe cases a 7270 and 7300 couldn't. I know it sure whipped my DC 300 A's and PSA 2. And with one ohm loads will out perform your 152 if properly restored. To get the better performance to drive a 1ohm load you need a pair of 611's. $$$$$$$. Or an ancient MC 2300 with one ohm taps as a start. A 2500 had one ohm taps . They easily put out 600 watts. But it would take a 1225 watt amp with a 1 ohm tap to supply the necessary 35 volts at 8 ohms like your 152 does. Now a 611 like a 501 should be able to meet specs driving a 1 ohm load from the 2 ohm tap maintaining the same distortion level suppling even more power. Your 152 will also from the 2 ohm tap but that still makes it 6 db short of the voltage from the 8 ohm tap. Fortunately most of the time with acoustical instruments the output at the highest octave is much lower than at the midrange. But if you get into digital music using Moog instruments that are all electronic, high frequency demands can escalate rapidly. This is not to say your 152 is not a great amp. it is. I'm just pointing out if you see your power guard lights flash with high frequencies being produced, you know why. It may never happen but it could. Thats why Accuphase amps that are direct coupled, and Quad balanced and are rated down to 1 ohm are revered in some circles. Thats why I love MC 1.2 amps. Connect anything to the 2 ohm tap and let things fly. My speakers are connected to MC 207's are supposed to be rated at 4 ohms for the woofers, but have a 1.5 ohm dip in a couple places,but I have never heard an issue with the 207,which I did with MC 2200's 2250's , 7270's and 7300's. I just didn't have space or the coin at the moment for three 7200's when introduced. I didn't make the mistake the next time.
     
    Last edited: Feb 13, 2018
  9. Velocityboat

    Velocityboat Super Member

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    Yes the MC2500 has 1 ohm taps. Top placard says capable of 1000 watts into 0.5 Ohms in mono.
     
  10. damacman

    damacman Blown and Injected Subscriber

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    OP - You know, I gotta' believe that an MC152 is capable of driving your speakers to levels beyond your comfort in a domestic setting. It's gotten rave reviews from owners and admirers alike.

    @twiiii - I was listening to Michael Murray's Organ Blaster Sampler (on Telarc) the other day at a realistic level - the tactile sensation of the ranks and pedals was pretty surreal and quite remarkable. On Tocatta and Fugue in D-Minor, I glanced at the meters and I was hitting peaks between the 60 and 600W marks per amp - so maybe 200-300W/amp. I lasted one more song at tha level as all the dogs left the room. Turning the system down a few clicks, I greatly enjoyed the rest of the disc.

    M fiance humored me but remarked later that the sound pressure upstairs was beyond ridiculous and that objects on counters were walking around. Just then, I thought - you know, an MC152 would likely be all anyone else would ever need. You could still almost pull that off. I'll keep the MC2600s for the occasional spirited listening session but the reality is 99% of folks would never need even 1/4 of the power.

    Reminds me of my relationship with my Olds' ... When I go WOT from a dig with heated tires, it accelerates so hard and so quickly, it scares me beyond explanation. Letting out of the throttle at the top of 3rd gear is almost a relief. I've had friends get out of it and an hour after they still have sea legs. OTOH, rollin' down the freeway at 75mph at 3,500 RPM and rolling gradually into the throttle to about 1/3 of the pedal, you're at 100mph effortlessly and instantly. Both are a rush - but I don't feel like I just cheated death doing that.
     
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  11. jayvis

    jayvis Well-Known Member

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    I agree with damacman. The MC152 will be a fine match with your speakers.
     

     

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  12. ddude003

    ddude003 New Member

    @twiiii, et al... I spoke to both McIntosh and Martin Logan about what MC152 speaker connection would be best to use 2, 4 or 8 ohm... Funny thing... They both said the same thing... Try them all and see which one you like the best... The McIntosh guy did say to check if there was any amplifier heating issue on which ever one I picked... I have had neither heat or power guard issues... About 15 Watts is about all I can stand with my system, in my listening space...

    Cordially...
     
  13. mg16listener

    mg16listener Member

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    Thanks for all the replies and input. When I created by login I had Magnepan 1.6 speakers and now they are are Dynaudio Special 25's. I have not owned Martin Logan speakers but perhaps my handle implied that. Sorry for any confusion to those who responded with their thoughts on ML speakers.

    Still waiting on my MC152. I am told it I most likely next week.
     
  14. ddude003

    ddude003 New Member

    @mg16listener - No confusion on my part... Only sharing my personal experience with my MC152 in my environment with you...

    Hurling 150 Watts of power thru 60 pounds of copper (read autoformers) into your blue charged listening space will be epic... 8^)
     
  15. mg16listener

    mg16listener Member

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    dude003 - Agreed. Looking forward to it. I was advise on Saturday my MC152 is in final production at the factory. So about another week or so is what I am told. I have been down a month or so since my Prima Luna tube integratred decided it wanted to go on a tube eating binge. Will send it off the get worked on but tubes have not been kind to me for some reason - hence a return to solid state.
     
  16. mg16listener

    mg16listener Member

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    72
    Hey everyone -

    Just received the MC152. Set it up and it appears the right meter is dead out of the box. The left meter works but the right meter does not deflect at all. I unplugged the left channel and moved it to the right channel. Sound yes - meter no. Looks dead to me. Any other things I should check or should I get it back to the dealer and have them get it returned and a new one sent to me?

    Not to happy with a brand new unit out of the box. Thanks.
     

     

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  17. Archguy

    Archguy Official Roiurama Factory Rep Subscriber

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    Man, I'd take it back in a flash. You bought it new? You've every right to expect perfection.

    Disappointing and dismaying. This isn't supposed to happen. What's your location? Are they still open where you are? My guess is that something came loose in transit but who knows. This is your dealer's problem, not yours. That's why they make the big bucks.
     
  18. mg16listener

    mg16listener Member

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    Closed for tonight. Going to call Mac in the AM and get in contact will the dealer. I waited a month for this to get here. They are 2 days away UPS. Perhaps the meter connection needs to be reseated. I could do it depending on where it is and what type of connection. But it makes you wander what else may be wrong. Going to test a few things to make sure the issue is not somewhere else but it does seem like the amp,
     
  19. mg16listener

    mg16listener Member

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    Another update: Checked with the balanced connections and same result - no right meter. Signal seems ok but not listening closely yet. AS well as it is packed it is hard to believe this is an issue caused in shipping but anything is possible. Hope they have some good answers for me.

    Update 3: I hooked up another DAC. I had been using the D150 and wanted to confirm it was OK as I had never used the variable outputs. Using an older Benchmark DAC's unbalanced analog outputs and optical out from an MCT450 to the Benchmark same result.

    Update 4: Swapping cables same result. The problem does not follow the cable swap. So after all these tests I feel it is the meter that is bad or perhaps a bad connection.

    Hopefully I can get this worked out without any grief. The silly thing is to heavy to lug around all over town
     
  20. c_dk

    c_dk Addicted Member

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    I am sure you have heard of it,Murphy's law, but since it is already taken I will introduce you to a new one.....SASP.....savy audio salesperson's law:

    We would open and test ALL major products before the customer took possession. Period, exclamation point. If they wanted to be there fine but We, the dealer, we were the final inspection station.

    I was not going to allow a customer to get upset because of a connection jiggered loose or broken glass.

    When UPS had weight restrictions all these units only came via selected trucking companies usually on a pallet. We had few problems.

    If the delivery and installation was a few hours away, with installers time tied up in drive time, the whole system was preset up.

    This included assembling and flying in our warehouse space complete rigged speaker systems when I was doing pro audio.

    This silliness about sealed factory boxes is just plain dumb....looking for problems. Make your dealer earn his profit and do his final due diligence.
     
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