Question about Yamaha a-u670 noise floor/hiss

hope

Novice Member
Hello. I want to build my first Hi-Fi system and considering availability and prices in my country I stumbled across a great deal, the Yamaha a-u670 paired with JBL Stage a120 and possibly a Yamaha Ns-sw050 subwoofer.

My question arises from the fact I had a pair of Presonus Eris 4.5 active monitors and in silence even without source connected there was an annoying hiss regardless of gain. It could be my house power but class D amplifiers make some noise and this Yamaha has one. I read the scarce reviews about it and for near field which is my intended use (pc) one user commented the same situation with normal sensitive speakers.

Does anyone who has this amplifier can comment on its noise floor? I'm very sensitive to this kind of noises and I was wondering if I should invest in a class D amplifier or get a more ideal pc solution like some Edifiers s1000mkII or s350db and leave the Hi-Fi setup to a greater listening field.

Thank you in advance.
 

Paul7777x

Distinguished Member
I’m not familiar with the quality of the electricity supply where you live, but it’s possible it could be causing some issues.

There’s no reason to suppose that class D amps are inherently noisy though. Quite the opposite in fact.

As you’re after speakers for a pc I’d suggest active speakers anyway.

(Your Presonus 4.5 are not active speakers by the way. They are simply passive speakers with the amp in one speaker).

The Edifiers are well liked and they’d do a great job I’m sure. Plenty of bass from the 350 too.

If the hiss is still audible you might want to consider a mains ‘cleaner’.

If you can find the equivalent of this in Argentina it may help.

 

hope

Novice Member
Thank you. I will research further into the electricity matter.

As for the speakers I will go with the 350 for convenience and when I get some spare cash buy the amplifier before is sold out and later add some speakers because it's a one of a kind deal. I can use the edifier for a tv later too so the versatility is a great factor. If there's any noise problem I'll update.

Cheers.
 

TB Rich

Active Member
@hope I have the Yamaha A-670 (same as the A-U670 but without the DAC) on my 2nd system - and there is only a small hiss from it when you put your ears up to the speakers - not audible sitting 2m away.
Even at max volume the hiss is only slight, but you can hear it at 2m away by that point - it is unrealistic to have the amp at max volume anyway!

This is connected to some Dali Zensor 1's rated at 86.5dB sensitivity.

It's a good cheap amp really. I set the tone control to about 2'oclock as otherwise it's a touch lean, and it feeds a sub via the subout too very well - no complaints at all for the money and I figured a safer bet than some cheap unknown chinese brand amp.

I wanted to build my 2nd system for as cheap as possible really, if you have a bit more budget the Yamaha WXA-50 will be a better bet, better amps and also with built in streaming etc.
 

hope

Novice Member
@hope I have the Yamaha A-670 (same as the A-U670 but without the DAC) on my 2nd system - and there is only a small hiss from it when you put your ears up to the speakers - not audible sitting 2m away.
Even at max volume the hiss is only slight, but you can hear it at 2m away by that point - it is unrealistic to have the amp at max volume anyway!

This is connected to some Dali Zensor 1's rated at 86.5dB sensitivity.

It's a good cheap amp really. I set the tone control to about 2'oclock as otherwise it's a touch lean, and it feeds a sub via the subout too very well - no complaints at all for the money and I figured a safer bet than some cheap unknown chinese brand amp.

I wanted to build my 2nd system for as cheap as possible really, if you have a bit more budget the Yamaha WXA-50 will be a better bet, better amps and also with built in streaming etc.
Thanks for the feedback. The Yamaha WXA-50 is a great option but it's almos twice as expensive here, the same as the A-u671. I planned to use the USB DAC on your amplifier for my desktop but the Edifiers should suffice for the time being.
 

hope

Novice Member
Just a heads up. I received the Edifier s350db and they have the infamous problem of whining on every mode except optical and coaxial. It is extreme annoying and unbearable, you can read more about it here: Edifier S350DB high pitch noise defect

So now I have the choice of changing them and see if the problem persists or straight up return them and look for other options, either the a-u670 or the Mackie mr524 monitors (said to be quiet) are my next choices.
 

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