[Lecrocodile]

Hi,

I currently have a Yamaha WXA-50 which is an integrated amp with DAC and streaming features in a small form factor.
Mobile App, feature set, power consumption... everything is fine.

Except that it replaces a Rotel 2x40w amp and despite the better power figures of the Yamaha (2x55 @8/ 2x105 @4), it doesn't sound as good as the rotel.
It lacks some oompf or i would say... I want to push a little further.

As I like the features and access of the Yamaha, i'm considering the pre-amp version of it, the WXC-50.
To which - here's the point of my post - I'll connect an amp from Nuprime.

So, I'm hesitating between the STA-6 and STA-9.

Both will match the form factor of the Yamaha and I don't need XLR outputs.

The thing is only STA-6 has trigger input so when i decide the Yamaha will go to sleep, the STA-6 will too.
It might save me 20 to 30$ a year. Not giant money but i kinda like the idea to switch both off at the same time.

The STA-9 will be always on, as the access to the rear is difficult and I don't want to make it more complex to start up for the wifey. TV sound output goes to the Pre-Amp/Amp all the time.
Advantage of the STA-9 is the little additional power, 35w per channel exactly.

All the Internet is talking about how much an amp can deliver current. And it's something that isn't listed anywhere.
And I'm trying to understand what would be the current/real world power difference between the two.

My actual speakers are easy to drive, bookshef format with 90db on 8ohms.
But I'm considering changing for Dynaudio bookshelves with 85db on 4ohms.
Listening to medium volume in my 30 square meter living room.

- Can we deduce the current capability of the two amps by looking how much the can produce power in mono mode ?
because when the difference is like +40% for the STA-9 in stereo, it goes up to +80/90 in mono. That's a big step up.

- Is there a toroidal power supply underneathe the metal protection on the right side of the STA-6 ?
Can we have a picture of what's under this plate ?

I don't think the difference in warmth is important to me.


Thanks for your comments 

[rustydoglim]

Go with STA-6.
If you change to a less efficient speaker, you can always configured STA-6 into mono and buy another one.
At $399, this is a no brainer. You can't even DIY and build anything better sounding and cheaper than $399.

[rollo]

Go with STA-6.
If you change to a less efficient speaker, you can always configured STA-6 into mono and buy another one.
At $399, this is a no brainer. You can't even DIY and build anything better sounding and cheaper than $399.

  Excellent suggestion. Go for it.

charles

[left channel]

You wrote "I don't think the difference in warmth is important to me", so maybe this won't matter but I find the STA-6 and STA-9 sound very very different. The STA-9 is also more powerful. I have mine on a power strip that I use to shut everything off when not in use.

[Lecrocodile]

Go with STA-6.
If you change to a less efficient speaker, you can always configured STA-6 into mono and buy another one.
At $399, this is a no brainer. You can't even DIY and build anything better sounding and cheaper than $399.

Thanks for your answer rusty.

Is there a toroidal transformer behind the metal plate in the sta-6 ?

[rustydoglim]

No. To get to this price point, STA-6 amp and power supply were designed as a system.  Sure the amp could use a different power supply, but the power supply was designed for this amp only. That's how we can bring the cost way down, and also keep it small.
To put a linear power supply in it, it would defeat the purpose of this product - small, powerful, light weight, and cheap (sure there are cheaper amps out there, but not at this quality).