Peter Walkers Quad

[DavidEdwinAston]

I know that it isn't remotely, his Quad company after all these years!
However, can you guys who understand the technicalities of amplifier specifications, explain to me why the current Artera mono amp. appears to be far more powerful than the Stereo version. This is going by the figures on the Quad website.
Thanks guys.

 

[Blumlein 88]

I don't think it is a big mystery. Same case (same exact dimensions listed). One is stereo and one is mono. My guess is they took the same power supply in both, and in one case you are supplying 2 channels and in the other just one. One is 140 watts and the other 300. The mono amp does weigh 2 kg more. But more or less that is what is happening. Roughly same amp doing one channel instead of two. Probably upped the output section voltage on the mono version as well.

 

[DSJR]

Isn't the power supply and basic circuit different for each though? the Mono is 300W at 8 ohms

The previous QMP was a totally different amp design to the then 909/QSP despite looking the same. I'll check the current specs, but the QMP was almost double the power output into 8 ohms I recall...

Artera Mono - QUAD

www.quad-hifi.co.uk

For general domestic use, at least in the UK and Europe where cost differences may not be as much, the Artera Stereo is a great and domestic-durable traditional amp (if fifty year old current dumping designs can now be called traditional) and continued small tweaks here and there have helped keep the specs competitive with similar models. The Artera Play ain't bad either... Thing is, in our local audio salon amongst the acres of Naims-in-Fraims and Accuphase on the other side when I visited last, the Artera units are all but hidden on a display shelf system...

 

[DavidEdwinAston]

Thank you both. Power supply is something I'm trying to get my head around, with regards to output power.
I think, another thank you to this site, from me!!!!!

 

[Hayabusa]

I don't think it is a big mystery. Same case (same exact dimensions listed). One is stereo and one is mono. My guess is they took the same power supply in both, and in one case you are supplying 2 channels and in the other just one. One is 140 watts and the other 300. The mono amp does weigh 2 kg more. But more or less that is what is happening. Roughly same amp doing one channel instead of two. Probably upped the output section voltage on the mono version as well.

It is bridged.. and has a lower power supply voltage.

 

[Blumlein 88]

It is bridged.. and has a lower power supply voltage.

It could be that, but I'd expect with a bridged amp it might be more limited into low impedance speakers. More than one way to skin a cat.

 

[Chrispy]

It could be that, but I'd expect with a bridged amp it might be more limited into low impedance speakers. More than one way to skin a cat.

That was my thought, but what are the measurements into various impedance loads?

 

[Hayabusa]

That was my thought, but what are the measurements into various impedance loads?

There is still no review for the mono, but the stereo was measured down to 1 ohm:

https://www.milovandewalle.be/wp-content/uploads/2021/03/Quad-Artera-HFN-review.pdf

 

[DavidEdwinAston]

I have just been toggling between the Quad site specs, for the two amps.
If I am correctly seeing that rated output power for the stereo is 140 into 8 ohms with less than 1% THD, and the mono is, 300 into 8 with 1% THD?
Could that be saying that the stereo will be putting out more power than the stated amount, by the time it gets to the 1% distortion level of the mono?
Not actually another 160 watts, I guess.
Anybodies far more informed view on this will be welcome.

 

[Hayabusa]

I have just been toggling between the Quad site specs, for the two amps.
If I am correctly seeing that rated output power for the stereo is 140 into 8 ohms with less than 1% THD, and the mono is, 300 into 8 with 1% THD?
Could that be saying that the stereo will be putting out more power than the stated amount, by the time it gets to the 1% distortion level of the mono?
Not actually another 160 watts, I guess.
Anybodies far more informed view on this will be welcome.

No its both the same distortion claim. Its for both the 1% mark

 

[Blumlein 88]

I know this is over-simplified. Think about having a horse to do your work. One horse per channel in the stereo version. You get 1 horsepower per channel. Now imagine you have the same two horses in the same box. Instead of hitching each one to a channel, you hitch both together for one channel. Now you have 2 horsepower per channel. 140 wpc is close to a two to one ratio with 300 wpc. The particulars of how they set power supply voltage, heat dissipation and whatever are details. In essence you just have two channels combined for twice the power into 1 channel.

As for distortion, both ratings are for 1% THD. Possibly/probably the 300 wpc channel amp will have less than 1% THD if run at 140 wpc. It likely isn't a dramatic lowering of THD. It might be .5% or .2% though how much varies with the particular amp.