XTZ AP-100 Review in HiFi World

[audiosanctum]

We are pleased to announce that once again we have received a highly positive review for one of our products. This time HiFi World have had for review the XTZ AP-100 Power Amp. Here are some of the comments from Tony Bolton the reviewer.

"Imaging was good... the soundstage extending beyond the speakers and also coming out into the room and back through the wall a little."

"The precise, almost mincing pace of the track was exquisitely descibed, and the over emphasised, vowel-strangling enunciation of the chorus was perfectly rendered... The almost delicate precision of the music seemed to suit the XTZ's style of presentation."

"Rhythms were quite propulsive and energetic, and the whole piece seemed to flow with a cohesive energy that was both pleasant and convincing".

FOR:

-clean, fast sound
-plenty of power
-switchable Class A
-solid build

AGAINST:

-nothing at the price

HiFi World Verdict - Decently smooth yet usefully muscular, this power amp punches way beyond its price point in sonic and value terms.

The XTZ AP-100 received 5 Globes.

For more information on the XTZ AP-100 please click here (http://www.audiosanctum.co.uk/Power-Amplifiers/XTZ-Class-AP-100-Power-Amplifier-Silver-and-Black.html).

[Darren]

..... And for around £500 it appears to be great value.
I notice that the bridged output figures don't make any mention of the class A output. Does that mean that a pair of these can't be run as class A monoblocs?

[Reid Malenfant]

Hi Darren, from what i have learn't these are sliding bias class A amps up to 50W per channel 8 ohms class A, above that power level they'll go into class B ;)

Now assuming the same current is available they'll manage 25W RMS class A into 4 ohms & 12.5W RMS class A into 2 ohms per channel :)

If you were to bridge one & power an 8 ohm speaker you'd manage to develop 25W RMS in class A as the each amplifier would see the equivalent of a 4 ohm speaker current wise :cool:

Hope that helps :)

[Darren]

Hi Mark,
Thanks for explaining. I have clearly misunderstood the term "switchable". I had presumed that this amp operated more in the manner of the old Marantz PM4 which offered 15w class A or 50w class A-B at the flick of a switch.

I guess I was hoping for a pair of 100w Class A monoblocs for a grand,...... wouldnt that be something?

[Reid Malenfant]

Hi Mark,
Thanks for explaining. I have clearly misunderstood the term "switchable". I had presumed that this amp operated more in the manner of the old Marantz PM4 which offered 15w class A or 50w class A-B at the flick of a switch.

I guess I was hoping for a pair of 100w Class A monoblocs for a grand,...... wouldnt that be something?
No worries, it's not switching anything in reality but when it goes above the class A bias level then one half of the output transistors will switch off - that's class B... At that point it carries on delivering power up to it's maximum RMS rating which might be 100W RMS into 8 ohm per channel??? I can't remember :doh:

As it's got a fairly hefty PSU it'll probably be good for up to 350W - 380W RMS into 8 ohm if bridged (class B) but with 12.5W RMS (which is still quite loud btw) of class A power..

Not to be sniffed at imo

[Ali Tait]

Yes, as long as your speakers are not too difficult a load, the amps would spend almost all their time in class A.

[The Grand Wazoo]

What about vertically bi-amping with a pair? Sometimes that works better than bridging amps to mono.

[audiosanctum]

Hey guys, ust thought i might confirm a dew things in response to the comments above...

About Marks post where he explains the current vs class A power, he´s almost got it alright except for bridge mode. He says the amp sees a 4 ohm load when connected to an 8 ohm speaker in bridge mode, which is correct, but what he´s got wrong is that the current is still constant and good for generating the same voltage across the load impedance, so the class A power area is still the same even in bridge mode, but the class AB area is extended considerably.

So still not bad for just over a grand ;)

[audiosanctum]

What about vertically bi-amping with a pair? Sometimes that works better than bridging amps to mono.

You can do that too with this amp. You would need to split the singal from the pre unless the pre out has the posibility for bi-amp or tri-amp.

Tri-amp, that would be a nice set up...

[Reid Malenfant]

About Marks post where he explains the current vs class A power, he´s almost got it alright except for bridge mode. He says the amp sees a 4 ohm load when connected to an 8 ohm speaker in bridge mode, which is correct, but what he´s got wrong is that the current is still constant and good for generating the same voltage across the load impedance, so the class A power area is still the same even in bridge mode, but the class AB area is extended considerably.
:eyebrows: Cheers for making me do a bit of math, you are dead right & indeed i was wrong about the power in bridge mode :doh:

That's a nice amount of class A power :)