[jac86]

I am shopping for an amplifier for my home theater. 7 channels, 125-150wpc, under $1,500.


I would like it to run relatively cool and, of course, not introduce distortion into my listening.


What should I look for in the specs/build quality?


I'm particularly interested in whether I should lean towards class A/B, D, or H. Or something else. Keep in mind the price limit.


I'm not looking for make/model recommendations unless you are really impressed with one.


Additionally, my pre/pro has an output voltage of 1.0 volts. Most of the amps I've been considering have an input sensitivity of either 1.0 volts or 1.2 volts. If I get one rated at 1.2 volts that doesn't have a gain adjustment pot, will this affect SQ, or just SPL?

 

[jac86]

bump

 

[JOHNnDENVER]

That is a lot of amps in one box. I'd separate them out some. Maybe go bigger on the power too.

 

[Knucklehead90]

I think you've described the Emotiva UPA-7 to a tee. And for that budget you could buy two of them!


I'm very impressed with mine. It runs cool and never seems to run out of power.

 

[Audiodork]

Hello,

The main things to look for in a Power Amplifier are the size of the power transformer and capacitance.


The most powerful multichannel amps have around or above a 2 kVA toroidal transformer and at least 30,000 uf of capacitance per channel. An excellent example is Parasound's Halo A51 which has a 2.2 kVA transformer and 164,000uf total of capacitance. This is a 5 Channel amp however.


There are not very many high power 7 channel amplifiers. It is hard enough to fit a large transformer and capacitors in a chassis for a 5 channel amplifier.

Adding an additional 2 channels goes beyond what many Companies do. Instead, many advocate using a 2 channel amp and a 5 channel amp.

With the Halo example they recommend using the A21 with the aforementioned A51 for a 7 channel application. This is an expensive combo, but is truly one of the better ones out there.

Cheers,

AD

 

[Selden Ball]

FWIW, Marantz sells the 8-channel MM8003, although it's priced above your indicated budget.

 

[Lhasa-lover]

This is in your budget.


Sherbourn. The 7/2100A includes 7 mono blocks, 7 toroidal transformers, 7 heat-sinks, 56 bi-polar/mosfet transistors, and over 140,000 micro-farad capacitance.

http://www.audiogon.com/cgi-bin/cls....A-7/2100-ampli

 

[JOHNnDENVER]

Consider two 4 channel amps where you could bridge two of the channels on one amp for your center.

 

[jac86]

Thank's for all the great answers. I didn't even know about those two specs

I'd like 2 amps over 1 based upon what you wrote. I would like a 3 channel and a 4 channel, but that option seems to be over budget.


So, I will probably go with one 2 channel and one 5 channel.


Benefits:

I can power on just the 2-channel amp for stereo listening.

I can get another (less powerful) 2 channel later on for heights.



I assume from your replies that the class (A/B v. H) shouldn't really be considered in my decision.

If I do get 2 amps, do I need to match them by any specifications?

 

[JOHNnDENVER]

Hmm give me till tomorrow and I'll come up with a two amp solution under budget.

I also like 200watt or greater per channel.

 

[MKtheater]

How long can you wait? How about an amp that uses 250,000 microfarads and a 1.5 Kva power supply? It is 6 channels and produces 150 watts per channel into 8 hms but the kicker is it will produce 350+ watts into 2 ohms. They go for around $500-$700 used. The Ada PTM-6150. They use fans as well as heat sinks. The Ada PTM-1260 uses 1.5Kva and 188,000 microfarads but rated at 265 watts per channel and 390 watts into 4 ohms but not 2 ohm stable since this power comes from it being bridged. It is stable into 2 ohms when operating in normal mode. Then of course we have the MPA-501 which has 500,000 microfarads and a 2.5 KVa power supply which go used for $800-$1200 depending on condition. If you have the time to wait for one then do it. I ran everything with these Ada amps and they are very clean, clear, powerful, and 2 ohm stable. I ran 8 sealed 18 inch subs of of 2 MPA's wired into 2 ohms per channel at ridiculous spl's. I like them better than the halo or older Parasound stuff. Can't beat them used.

 

[jac86]

As plans often change, I now have to wait until the 3rd week in March for my DHC-80.1 so I can wait about a month for the amp too.

I am running B&W 603s, LCR600s, and 580 rears. I wouldn't mind 200w, but would it be too risky a move?

 

[rnatalli]



Quote:
Originally Posted by Knucklehead90 /forum/post/18189643


I think you've described the Emotiva UPA-7 to a tee. And for that budget you could buy two of them!


I'm very impressed with mine. It runs cool and never seems to run out of power.

+1 Another option is trying to find a used Emotiva IPS-1 or MPS-2 which are really nice amps.

 

[Knucklehead90]



Quote:
Originally Posted by rnatalli /forum/post/18192635


+1 Another option is trying to find a used Emotiva IPS-1 or MPS-2 which are really nice amps.

There is an MPS-2 on Audiogon for $1500. 7 channels at 200wpc and 2 extra modules. Cconklin1 is a member here - he has that MPS-2 for sale here as well. If I were looking for more power - which I am not - I'd certainly take a look at that amp.

 

[jac86]

I just read an article that made total sense of why I'd be best off with 200watts for my 150w speakers. I think I'm going with the XPA-5 new. My decision was made even harder by the fact that Outlaw just put the 7125 on sale for $850.

 

[jac86]

Cancel that. I am the proud new owner of the Outlaw 7125. $850 until 2/26


I figured that once I'm ready to upgrade to heights, I can get a 200w stereo amp, and maybe go 200w on the center channel as well. All channels besides the L/C/R should be more than fine w/ 125w.


Thanks again to all of you.

 

[JOHNnDENVER]

Congrats!!


I think that will be a fine amp for you.....



Best of luck with your future amplification goals as well!!

 

[dtc]

Just to add a couple more options for future reference - ATI 1807 and B&K 200.7 are both robust 7 channel amps that can be found used in this price range. The ATI is 180 watts per channel and is single ended. The B&K is 200 watts per channel and is a balanced design. I believe that the ATI and the Outlaw are made by the same manufacturer, although I am not certain.

 

[MKtheater]

ATI is usually the manufacturer.