Best Emotiva amp to pair with Yamaha RX-V2400

[PSU80]

I am considering adding an amp to my Yamaha RX-V2400 which I use in 5.1 and stereo mode. The Emotiva UPA-7 obviously got a great review here but the XPA amps also appear to be highly regarded. Given the good review Audioholics gave my receiver (see below) I'm unsure if I would get much benefit from adding a UPA-7 or if I would be better off with a XPA-3 or 5. Any thoughts?

Excerpt from Audioholic's review of the RX-V2400:

A massive 11.9 lbs 640VA Power supply
2 x 15,000uF 71V storage capacitors
Complimentary Class AB push pull BJT's
These three attributes are responsible for the size and weight (35lbs) of the RX-V2400 and its ability to satisfy THX Select certification.

Given the size of the power supply, and the large storage banks, the RX-V2400 has potentially added headroom to better drive moderately difficult two channel loads. However, be cautioned that this receiver will NOT deliver anywhere near its rated power with all channels driven (nor is it specified too) which is not a realistic operational condition in any real world listening environment anyway.

I would venture to say based on the 640VA power supply rating and 71V caps, the RX-V2400 would easily deliver 120wpc X 2 and about:

80 wpc* (ref 1kHz) X 5 all channels driven
60 wpc* (ref 1kHz) X 7 all channels driven
*assuming line voltage held constant, 8 ohm loads

 

[m_vanmeter]

why do you think you need to add external amplifiers ?

You are pushing up to 120wpc (two channels driven) at .04%THD, so unless you are trying to fill a large auditorium with sound, there really should not be a need for more power. Even the Audioholics review claiming a "supposed" 80wpc with 5 channels driven should drive normal speakers in a typical home theater room to "ear bleed levels".

 

[PSU80]

Well, I guess that's really my question...would sound quality improve using an external amp in my situation. I'm not looking for "ear bleeding levels" but everyone seems to say that using external amps results in "cleaner, more detailed" sound. Having never owned an external amp I have no reference to know whether these claims are B.S. or dependant upon the the receiver in the equation.

 

[j_garcia]

No, sound quality will not improve. Adding more power allows you to listen at a higher SPL without (with less) distortion, so if you are getting adequate levels as is, then an amp isn't going to give you a significant benefit. Sound quality will only improve if your current system is struggling to deliver the levels you are looking for currently. The thing is, it is really tough to hear if your system would benefit if it doesn't sound strained. You can't reall hear that strain at average listening levels, or rather you shouldn't be able to anyway. The XPA line will definitely give you a big bump in power, but if you aren't looking for ear blistering levels of sound, then I'd say put that money elsewhere. If you are turning it up constantly and you feel like you reach a point where it either sounds distorted or like it isn't getting any louder no matter how much more you turn it up, then an amp may benefit you.

My speakers are all 4 Ohm and the XPA-3 made a very noticeable difference in how loud I can listen, but I like to listen LOUD

 

[tomd51]

If you're running 7.1, the UPA-7 would be your best bet. If you only have 5.1 and plan to keep it that way, the XPA-5 might be a better option, however the UPA-5 is also a nice addition for a 5.1 configuration.

I previously owned a Yamaha RX-V2500 and while the built-in amps were relatively solid for a small to mid-sized room (less than 3000 cf), I certainly did notice an improvement in detail with external amplification for the front soundstage (LCR), particularly with two channel and hi rez music. Granted my listening area is on the large end of mid-sized, I felt it was worthwhile when listening at higher volumes (85 dB or more), even for short periods. Speakers and you're listening environment are going to have the biggest impact on how things sound, but a good receiver, pre/pro and amplification can make modest improvements.

I've always been of the mindset that assuming you can afford it, the more amplification (within reason), the better. If you're listening area is less than 3,000 cf., I'd suggest the UPA-7 or UPA-5, depending upon whether you're running 7.1 or 5.1. You could even use a UPA-5 and the on-board amps of the 2400 for the rear in a 7.1 configuration as there's little power demand for the surrounds and rears in most setups. Worst-case scenario, if you get one of Emotiva's amps, calibrate using YPAO and/or SPL meter, do some listening tests with movies and music you're familiar with and find it doesn't make a worthwhile difference, you can always send it back w/in the first 30 days and you're only out return shipping. I have a feeling you'd hang onto it, though... -TD

 

[Seth=L]

I think the dynamic headroom capability of a separate power amplifier is often overlooked. Power and it's relation to speakers and output are misunderstood a great deal. It's almost always over or underestimated, sometimes by the same individual.

I believe you could absolutely notice a difference in fidelity by adding an external amplifier for certain source material. Dynamic source material requires dynamic power to match it for optimal fidelity. Even at moderate listening levels a transient can be lost on lower power equipment when the power supply simply runs out of gas. The UPA-7 can deliver several hundred watts to one or two channels instantaneously if necessary. I could not say the same for the Yamaha, even for a receiver as robust as the RX-V2400 is. The Emotiva can do this because it has a large centralized power supply and rugged output channels, each with higher quality transistors and heavy aluminum heat sinks. The heat sinks inside the Emotiva are as large or larger than ones found in most receivers.

The Emotiva will also offer more stability with low impedance, which your speakers may impose at certain frequencies. Because most music and soundtrack material doesn't dwell on a particular frequency for long periods of time they may not take a receiver to it's breaking point, however the sound may be affected when it encounters difficult loads that it is unable to supply adequate power.

Since we cannot assume the receiver will always be in comfortable operating conditions, even at moderate levels of output, we can't assume that adding additional amplification would not be beneficial.

 

[PENG]

but everyone seems to say that using external amps results in "cleaner, more detailed" sound.

I see no evidence of everyone saying such things. Some did, but probably less than 50%. Most people seem to say that external amps could result in cleaner sound at volume level that is beyond the power output capabilty of the receiver in question.

Having never owned an external amp I have no reference to know whether these claims are B.S. or dependant upon the the receiver in the equation.

I had A/B'ed the 2400 against Anthem separates using speakers including some floor standing KEF and Paradigm Studio 100 V3 and I could not say one was better than the other. That was for 2 channel, I do believe the 2400 can use some help in multichannel applications but again, it all depends on how much power you need. If the power you need is well within the 2400's capability then adding an emotiva amp will not get you better sound quality.
That being said, like money, having more than you need is obviously better than just having "enough".

Some people may tell you that even at very low volume level, adding an external amp will still get you clearer and more detailed sound. Such claims are not supported by science and engineering except in the case of entry level receivers, certainly not mid range models such as the 2400. Engineers who design amps would likely tell you the same.

 

[PENG]

I believe you could absolutely notice a difference in fidelity by adding an external amplifier for certain source material. Dynamic source material requires dynamic power to match it for optimal fidelity. Even at moderate listening levels a transient can be lost on lower power equipment when the power supply simply runs out of gas.

I believe that too. What I do not believe is the kind of blanket statements that claim unqualified and seemingly exaggerated improvements using expressions such as day and night, huge etc.