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Need Advice on Multi-channel Amp Choices.

Hi All, basically I am in need of a new Multichannel power amp for my room.

Setup consists of 7.2 configuration

  • Arcam Av950 preprocessor
  •  Monitor Audio Platinum Pl300 fronts
  •  Platinum pl350 Center
  • 4 x Gold GXFX Dipole Surrounds
  • Dual Monitor Audio Gold Subwoofers. 

My listening is 50 / 50 HT and Music. Music is 50 percent 2 channel and 50 % multi-channel sacd's.

Room Dimensions are 20ft long and 13ft wide.

Basically I have my eye on a number of used options but no way to Demo them.
  1. Earthquake Cinenova 7 Grande
  2. Audiocontrol Savoy G3
  3. Classe CA-5100

All of the above are pretty close in price, a shade over 2 grand. The Audiocontrol is new, The Earthquake 2 years old and the Classe from 2010. I am struggling to make a choice between them. Anyone got experience with these models, need a push to make a choice, thanks.
melmoth76
nutty
2,865 posts
 
Anthem Audio has many options. Very versatile. 
Many have independent power supplies for individual channels. 

N

erik_squires
16,056 posts
 
By the way I’m not a huge NAD fanboy. I really like nCore, and ICEPower though. The NAD DACs I’ve heard were not to my taste, but damn, I like the look and modular concept of their processors. :)

Arcam is also nice, but not a very good track record on upgrades.

Best,


Erik
melmoth76 OP
5 posts
 
Hi Guys, Thanks for all the responses. Firstly, I do indeed have those speakers and my room has decent treatments, I do have a vaulted celing at 14ft high which certainly comes into play a little bit.

I do not tend to listen at reference levels and find myself leaning towards the Classe CA 5100, The class A bias is certainly of interest to me as my prior unit was an Arcam AVR750 which I loved and was hands down the best sounding receiver I have ever owned, its first 20 watts per channel were in Class A.

My only concern is that the Monitor Audio Platinum Pl300's are considered to require significant power to get the best from them, they are 4 ohm and recommended amplifier of 100-300w. I like the look of the krell that Auxinput suggested but he correctly reasoned that I was looking for something a little newer.

Basicallly will the Ca 5100 drive my speakers adequately? or should I continue looking at higher powered options. Thanks Again!
auxinput
2,920 posts
 

@erik_squires - yes, I do agree with all your points on multi-channel amps. It is, basically, a compromise to get 5 or 7 channels into a single device and still perform -somewhat- well.

The Monitor Audio speakers are 4 ohm, which will make it more difficult for an amplifier to drive. However, it doesn’t really drop down below 4 ohms like some speakers do, and most of the impedance is readily above 4 ohms:

http://www.stereophile.com/content/monitor-audio-platinum-pl200-loudspeaker-measurements#6kWsTrvo8jKsRcRR.97

That being said, you will probably lose some midbass punch where the impedance is almost a flat 4 ohms between 100 and 200 Hz. Also, some areas in the deep bass. The Classe amp is probably the best choice out of your 3 because of the "Class A" bias, but it is not really the best choice for the speakers.

Yes, nCore and ICE Class D amps can generate more power, but in my experience in research, the frequency response of Class D amps are typically dictated by the speakers impedance curve, meaning that the lower impedance areas will affect how powerful the Class D amp outputs. A Class D amp will probably perform very well on a speaker that is almost a flat 8ohms across the entire frequency range (much like a basic 8 ohm resistor). I don’t know about the newer Class D amps, but this is what I found with earlier Class D.

I don’t know if you are taking suggestions, but I have owned the B&K Reference 7 channel before. It’s more power than the Classe (at 200 w/ch). It has a Class A pre-driver and good power supply. The amp had really good power and volume and it was very sweet sounding, but I felt that the sound was too warm for me. At the time, I was running a Bryston SP2 Class A processor, so it was too much Class A in the audio path for me, but I think it could work out for you if you want to consider it.

https://www.audiogon.com/listings/multi-ch-b-k-components-reference-200-7-s2-7-channel-power-amplifier-9286-2016-09-20-amplifiers-80020-broomfield-co

Otherwise, another suggestion is to start buying up used Emotiva XPA-1L monoblock amps and run them in the Class A mode (30 watts). They are typically less than $400 each used, so it is in your budget. The only problem is supplying a separate outlet (or heavy power strip) for each amp. You need space for 5-7 individual amps and they do get hot in Class A - so you will need a good 3" space above for heat ventilation.

erik_squires
16,056 posts
 
I found your comments about frequency response interesting. That would imply that they have high output impedance (or low damping factor) which they do not, by themselves have. Tube amps of course tend to behave this way. If you can point me to any measurements for the ICEPower or nCore amps which do this I’d love to check them out.

Most amps reduce DF (increase output impedance) as F increases, but older class-D amps pretty bad in this respect. If memory serves though, nCore and the later generation ICEPower units solved this quite well.

In solid state amps improving (reducing) output impedance is usually a matter of feedback, and in D class amps where the feedback is applied.

If memory serves, the feedback on the nCore is at the output stage, instead of before, a good thing. They have ridiculously low output impedance as a result. Any "frequency tracking" of the speaker impedance is not due to the nCore design.

I use bare ICEPower 250ASP based monoblocks to drive 4 Ohm speakers (min impedance 4 Ohms through mid bass) and they do superbly. The ICEPower amps replaced a pair of Parasound A23s, which are fairly well biased into Class-A for the first 30 or 40 watts. I could not hear a difference, so I completely converted. I was running the Parasounds in a 4.0 HT configuration, so 1 amp was left, 1 amp was right.

Best,


Erik
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