Emotiva BasX A7+ 7-Channel Amp Review

[Linnie]

Yes. You'll need to send the Left output from the preamp into two ins on the amplifier, and then out to the treble and bass binding posts separately.

Biamping like this won't make a big difference in sound unless you're really starved for power. But with this setup you're only one step away from pulling out the passive crossovers entirely and going active. If you take the preout into something like this Dayton crossover, physically remove the crossover from your speakers and wire the tweeter and the woofer directly to their respective binding posts, you can get a far bigger advantage, because you're now doing the crossover in the digital space prior to amplification, and connecting the amp directly to the drivers, which is much more efficient and allows much more fine-grained control over crossover, EQ, and things like correcting for time alignment of your tweeter and woofer.

Thanks a lot for your advice. ASR is really the place to go for information!

 

[peniku8]

There is no evidence that tube lovers are really hearing distortion and prefer things that way. Other than placebo effect, any real change is likely due to high impedance of the tube amp, changing frequency response of the speaker.

The tube amps I have heard, create a spray of distortion and not just 2nd harmonic, especially when you push them. Such distortion is quite audible, muddying the sound and creating high frequency grittiness. This is proof enough that people who buy such gear are not able to discern distortion.

My mind was more on the production side, but as far as music reproduction and power amps go, as you say, magnitude changes will be the first obvious differences and high Zout is gonna cause a bunch of that, especially with modern speakers which aren't designed for use with tube amplifiers (with Zobel Networks in place to flatten their impedance) anymore.

The tube amps you've tested indeed didn't show a pronounced 2nd harmonic, in contrast, the Engl amp I measured (guitar amplifier!) had quite a lot of that - before the inevitable odd orders set in when approaching its limits as you point out (and all the intermodulation that it brings with complex signals).

But hey, those things do look pretty!

When it comes to music production tho, the characteristic tube distortion profile is pretty much all the producers/engineers are after, just that they call it "saturation" instead, because that sounds nicer
Would be tremendously interesting to see how popular studio tube gear measures and what it does. The lower hanging fruit would be to see what the respective plugin emulations do.

 

[peniku8]

It's not clear to me whether the highest discrimination category erases truly exceptional scores because they are not large enough to merit their own category and thus get lumped in with the people who "only" discriminate -56dB down. Nonetheless, I'm confident that -80dB second order is well and thoroughly masked.

That is correct, since more people scored the highest result than the 3 next best results combined, but remember that the people taking the listening test are an extremely small subset of the population, a subset that is most likely to score well on this kind of test, then those who reach the maximum score are yet just another 3.5% of that subset and those who might reach even better scores is yet again a small subset... I wouldn't doubt that you can find someone with the "golden ears" somewhere, just like you can find people that can hear above 20KHz even past their 20s, but thats why tests like this exist and people should take it to see how sensitive to distortion (or how well trained to hear it) they actually are.
Also it's important to consider that the 3.5% of highest score results of the Klippel test are probably not reached with the music stimulus, but with the available test tones. I managed to do that with music once, using my HE6se at unpleasantly high volume in a room with very low ambient noise (<20dB). I just took the test again, on my speakers at normal volume with the windows open and birds chirping outside; didn't even manage to get past -30!

 

[Beershaun]

This amp doesn't seem to have any material advantage to typical onboard avr amps. Not sure why I would pick this over the equivalent price Denon integrated AVR?

 

[sealman]

This amp doesn't seem to have any material advantage to typical onboard avr amps. Not sure why I would pick this over the equivalent price Denon integrated AVR?

The brand new Denon AVR-S980H is basically equivalent to the A7+ price wise.
The S980 has 90 watts per channel with only 2 channels driven. So figure 55-70ish with 7 channels driven. The A7+ puts out 90 per channel ALL channels driven so there is an advantage with the A7+. Granted it is not a huge advantage but with low sensitivity speakers the S980 would most likely struggle in a medium sized room.

 

[IamJF]

The gain is a hair higher than specified 29 dB. I like to see this reduced to 25 dB.

EXACTLY! Or even 22-23dB.
This amps noise performance is not horrible but at least 6dBs are just thrown out the window. In Home Cinema you have >11 noise sources in a silent room. Speakers with high sensitivity to get enough dynamic range. A noisy amp is a problem.

And then throw away noise performance cause of ... ? what is the sense of these high gains in HiFi?

 

[IamJF]

This amp doesn't seem to have any material advantage to typical onboard avr amps. Not sure why I would pick this over the equivalent price Denon integrated AVR?

I use active front speakers + woofers with an AV preamp. And could need a good priced amp for 4 rears and a few ceiling speakers.
Or you drive a bass array for cheap and probably upgrade later (to gain 3dB ... maybe you never upgrade).

There are plenty of uses in modern multi channel systems for a cheap but good quality amp. But to be honest - this one wouldn't cut it for me.

 

[SynthesisCinema]

The brand new Denon AVR-S980H is basically equivalent to the A7+ price wise.
The S980 has 90 watts per channel with only 2 channels driven. So figure 55-70ish with 7 channels driven. The A7+ puts out 90 per channel ALL channels driven so there is an advantage with the A7+. Granted it is not a huge advantage but with low sensitivity speakers the S980 would most likely struggle in a medium sized room.

Going with D&M promise 70% of 2ch power spec for 5ch driven would be 63W. And then 7ch driven about ~20W less.

S980H has 2x 10,000μF 71V main filter caps. Total capacitance of 20,000μF which is same as Denon X2800H.

Emo A7+ has 6x 10,000μF 71V 105C = 60,000μF total capacitance which gets close to Denon A1H.

The A3+ would be my pick from Emotiva for powering LCR and then assigning the internal amps of X3800H/X4800H for effect channels.

A3+ = 3x 140/200W 8/4-ohm. 40,000μF total capacitance for 3 channels. For reference Denon A10H has 44,000μF total for 13 channels.

 

[SunByrne]

Would be super interesting to see direct comparison with what I think of as the most obvious competitor, the 7-channel Outlaw 7000x. The Outlaw 2220 is there, but not the 7000x.

 

[SuicideSquid]

Still I doubt anyone can hear the difference between this and the one like Topping LA90D.

Probably not, but again, we're talking about the difference between "good enough" and "great" here. This amp is "good enough", but for a similar price there are other options that give you more - a Hypex-based Buckeye that will give you more power and lower noise and distortion, for example, so why settle for "good enough"?

 

[BJL]

Probably not, but again, we're talking about the difference between "good enough" and "great" here. This amp is "good enough", but for a similar price there are other options that give you more - a Hypex-based Buckeye that will give you more power and lower noise and distortion, for example, so why settle for "good enough"?

The similar Buckeye amp is almost $700 more than the Emotiva. Not everyone can afford.

 

[cardan]

Surprised, usually their stuff is shit. Was a Emotiva owner for 6yrs...

And about 2 years ago I had a horrible experience with their customer service and my Basx4 amp.
Because of that, they lost me as a customer - for life. I sold the 4 ch Basx power amp and replaced it with a Nord One Class D Hypex based NC252 8 Ch amp (4 surrounds + 4 ceiling). Very pleased with it. No comparison. Buckeye should be an excellent option too. Emotiva customer service? Never again.

 

[Peib]

thanks for sharing

 

[Scrivs]

The implementation of the cooling fans look like an afterthought.
Nice heatsink though!
Perhaps Emotiva could have saved all of the "development effort," and filled that nice looking enclosure with the requisite configuration of Icepower, or Hypex UCD modules instead of the standard AVR-style multichannel A/B effort that we have here.
Mahalo nui loa for the test!

 

[AudioKC]

For not much more money, a Hypex NCx252MP 6-Channel ($1350@Buckeye) gets you more power and much better specs in every way, likely including longevity due to cooler operating conditions. I realize that a 30% increase is not insignificant, but sometimes the cheapest way to go is not the cheapest in the long run

My first thoughts when I saw SINAD + Power. +1