Emotiva BasX A-500 5-ch Amplifier Review

[DonH56]

Without mu-metal and grounded chassis the transformer could be injecting energy into the chassis etc. Toroids constrain but do not eliminate the fields, making it easier to put components closer, but not a complete panacea. There could also be leakage paths from the primary side wiring, etc. But, this is not really my field (no pun intended).

 

[Lotus97]

I think the Emotiva A-5175 model is the one to buy, it costs more but worth it over these A-300 and A-500's, even if you planning for stereo use, the A-5175 model is still the way to go, 175w x 2 into 8ohms. And the inside of the A-5175 looks a lot different, different transformer, and other things. I am just wondering how it would measure when compared to A-500 model.

 

[scooter]

I'm just curious, bottom part of the fixing bolt in the center of transformer, is it grounded to the chassis? If so, doesn't it act like another "secondary winding" freely applying "one phase" of an induced voltage to the chassis?
If so, does it going to help if the top part (nut) is also connected to the chassis to cancel any potential difference?
I realize that 5cm straight bolt is not the same as coil, but still it is a conductive material...

 

[Lotus97]

"Ultra Low Noise" transformer... Imagine how it would measure with a noisy one.

So you think the circuitry of the design is not that good that they had to use the ultra low noise trans? I think its just an advertising thing, most if not all amps use low noise transformers.

anyway, after looking insides of units like that from Hegel amp and this model it is like 70% of the insides is missing from this A-500 amp.

 

[scooter]

So you think the circuitry of the design is not that good that they had to use the ultra low noise trans?

I think it was a sarcasm

 

[Lotus97]

I think it was a sarcasm

lol, I thought so too. Sometimes you're just not sure.

 

[Evenor]

Very interesting review. It's interesting to see how budget class AB power amplifiers perform compared to the excellent measuring NCore amps. I would be interested to see similar amps from Parasound reviewed.

For my desktop setup, I'm using a Parasound Zamp v.3. It massively benefitted from a power conditioner so I assume it has similar issues like this amplifier when it comes to mains noise. I have been very pleased with it when using it with a power conditioner and it has been far from the weakest chain in my setup, at least until now. A Parasound Zdac 2 got replaced by a Topping D50s last week which lead to a huge reduction of noise and much cleaner and clearer sound.

 

[doodlebro]

I think the Emotiva A-5175 model is the one to buy, it costs more but worth it over these A-300 and A-500's, even if you planning for stereo use, the A-5175 model is still the way to go, 175w x 2 into 8ohms. And the inside of the A-5175 looks a lot different, different transformer, and other things. I am just wondering how it would measure when compared to A-500 model.

I went with this and I like it. Definitely has mains hum but not audible unless you are within a few feet of speakers. I use it for all of my front speakers, including heights.

 

[Rover]

I use an A150 power amplifier with 4 ohms acoustics. At 150 watts there is no low-frequency background.
Even 1 cm from the low-frequency speaker. Complete silence. This suggests that the A150 has no A500 flaw or rather that the A500 that Amir tested was factory disadvantage covered by the warranty case.

 

[Promit]

I could not get the amplifier to distort less than 0.1% with 4 channels regardless of output level. So I stepped that up to 0.2% to get the third graph. I could have been watching a movie instead of running these extra tests so I hope you are happy!

Wait what? It always distorted more than 0.1% at 4ch driven? That seems like a catastrophic degradation in performance! I don't understand how that is not completely disqualifying.

 

[tcramer]

I am setting up a 7.1.4 system with a Denon X3700. Speakers are Revel in walls all around (W990s, C/W530s) so 8 ohm and solid sensitivity. Subs will be crossed over around 80 Hz. I need a 2 channel amp to drive the full 11 speakers as the AVR only has 9 built in amps and was debating 2 options.

1. Getting this BasX A-500 and only using 3 channels to power the LCR. I'd assign the LR to external and use the "hot" preamp out for the center.
2. Just use a simple class D 2 channel amp (like Russound P75, Amazon Basics etc) for about $120 and use this for top rears (the only other assignable option beside LR).

Without the need for extremely high listening levels, would I gain anything by going with option 1? Or should I save them $400 and just go with the cheap 2 channel amp?

My thinking was taking these 3 speakers out of the Denon's power would provide them with dedicated power and free up power for the rest of the channels, also allowing the Denon to run cooler.

Appreciate any thoughts on this.

 

[RocketLeague]

I am setting up a 7.1.4 system with a Denon X3700. Speakers are Revel in walls all around (W990s, C/W530s) so 8 ohm and solid sensitivity. Subs will be crossed over around 80 Hz. I need a 2 channel amp to drive the full 11 speakers as the AVR only has 9 built in amps and was debating 2 options.

1. Getting this BasX A-500 and only using 3 channels to power the LCR. I'd assign the LR to external and use the "hot" preamp out for the center.
2. Just use a simple class D 2 channel amp (like Russound P75, Amazon Basics etc) for about $120 and use this for top rears (the only other assignable option beside LR).

Without the need for extremely high listening levels, would I gain anything by going with option 1? Or should I save them $400 and just go with the cheap 2 channel amp?

My thinking was taking these 3 speakers out of the Denon's power would provide them with dedicated power and free up power for the rest of the channels, also allowing the Denon to run cooler.

Appreciate any thoughts on this.

High listening levels is definitely the important factor here. In my experience, I would insider my needs similar but sometimes I still find myself watching something with quietly mixed audio and turning my system higher than I ever expected I would. That is to say, you’d certainly enjoy the headroom of the more expensive option #1. Perhaps try option 2 and if not ideal, return or repurpose that cheap amp.

 

[DanTheMan]

I have the older version of this amp—the 70 lb version— and I have to say that I am not impressed. It is powerful for sure, but it just doesn’t sound as clear and open as my Yamaha AVR (my apologies for the subjectivity). I use it to power my multi sub set up, but it doesn’t really excel there either. The receiver doesn’t have good enough controls to optimize a multi sub set up and the amp itself doesn’t help at all. I actually does provide enough power, but I doubt it would with smaller subs (I have all 15” subs). Overall, I wish I had spent my money on something else, but it took me too long to figure that out. Not a horrible product by any means, just not great at what I bought it for—a 5 channel surround sound amp.

 

[hakanfw]

Hi there... a "first"
Yes I like their idea - bang for the buck.
BUT, this about no ground and poor chassis ground... me no like!
Somewhere Amir (i think) wrote about 14 ohm between rca- and chassis????
What??
I am not an electrical engineer, but I would ad ground everywhere - new mains connector WITH ground, chassis connection, check rca ground...
Will I kill myself and the amp, or will I actually get better control over mains hum and difference between the channels.

I mean, It simply cannot be intended from the designer???

 

[MZKM]

The bandwidth is very different. Dashboard uses 22.4 kHz, the THD+N vs Frequency uses 90 kHz.

What about amps? This Emotiva shows 0.03% in the dashboard but the THD vs level shows 0.01% @ 5W 4ohm.

 

[somebodyelse]

Hi there... a "first"
Yes I like their idea - bang for the buck.
BUT, this about no ground and poor chassis ground... me no like!
Somewhere Amir (i think) wrote about 14 ohm between rca- and chassis????
What??
I am not an electrical engineer, but I would ad ground everywhere - new mains connector WITH ground, chassis connection, check rca ground...
Will I kill myself and the amp, or will I actually get better control over mains hum and difference between the channels.

I mean, It simply cannot be intended from the designer???

As you say, you're not an electrical engineer. It's built to internationally recognised safety standards - you'll find the Class II double insulation symbol on the back panel near the CE mark - so you should be safe. 14R between chassis and RCA isn't necessarily a problem either - it's not uncommon to have the amp board using a controlled connection to the chassis via resistor/capacitor combinations, or using diodes. If you buy amp modules you'll usually find details of the recommended method to connect it to chassis (or not) for best performance, and what components may be between module ground and its chassis connection.

 

[Annoyed82]

I bought this one as my first )and so far, only) Power Amp. I use all 5 channels-LCR and surround backs in a 7.1.4 set up with the Denon X3700 as the AVR.

I found it does help at mid-to high volumes, not so much when at low loudness. Sound is clearer and more defined, I also noticed more bass and cymbals and highats sound clearer and there is overall better separation.

I used a decibel meter and was able to get up to spikes of 108db at 1 meter from the center speaker with the volume turned 2/3 of the way up.

 

[EdTice]

Other than that, it is a definite step up very amplifiers in AVRs.

Overall I can recommend the A-500 if you are on a budget and have a bad back stopping you from lifting something heavier.

I must not be very good at reading comprehension. Because nothing in the review makes me think that this amp is a lick better than using the built-in amplifiers in my X3600H! Probably better than the amps in my older Yamaha AVRs but those have such weak DAC/Pre sections that it wouldn't matter.

 

[HeadroomRules]

Hello Amirm!
First time poster here. I know this thread is older now, but I am hoping that you can recommend any other 5-channel (or 4.1) amplifiers for under $1000.
Thank you for ASR. I’m really enjoying it!

 

[blazen2150]

I must not be very good at reading comprehension. Because nothing in the review makes me think that this amp is a lick better than using the built-in amplifiers in my X3600H! Probably better than the amps in my older Yamaha AVRs but those have such weak DAC/Pre sections that it wouldn't matter.

hey i own my Yamaha a2070 and it rocks, i only use it to power up the center and 2 surrounds and 4x atmos ceiling, 2 mains is ran off an crown AB amp because mains use up the most power