Who are the competitors for good class A amplifiers?

[cjf]

Not sure if the OP is aware of this info related to Pass Labs amps but most of the Amps they make, even the ones considered A/B, still offer some number of Class A watts before going A/B mode. This is good because it opens up your options a bit when shopping around on the New or Used market.

 

Below is a chart from one of Nelson's Tech articles on "Leaving Class A".

 

 

I'm not able to find it anymore on the Pass website but there used to be an equivalent document to the one linked below for the .8 series showing the wattage output of Class A power for the older model Pass Labs amps classified as A/B units (ie..X150,X250...etc). In short, most of them have at least 10watts of Class A on tap.

 

https://www.passlabs.com/wp-content/uploads/2019/12/Point8_specs_8.pdf (Scroll to bottom for Class A/B amps and look for Leaves Class A)

[cjf]

On 1/16/2022 at 2:52 PM, AudioDoctor said:

Pass XA30.8 is another solid option. I was under the impression that Magnepans required a lot of power to drive properly? There certainly are Class A amps that make big power, they also make big heat.

Looks like there is one of these for sale now on Audiogon for a decent price (I'm not the seller but noticed it). I think the XA30.8 would be a perfect fit for the OP.

 

I've never really noticed the heat concerns with any of the Pass units I've owned in the past or currently. In the past I've ran a large X250 in a pretty small room and never noticed much added heat in the space as a result. But with that said, maybe I'm just oblivious and its there without me really thinking about it.

 

I think my XA60.8's run even cooler than the old X250 did. They are currently running at 103deg on the top plates of both and that is after about 4hrs run time at "energetic" output levels. 😀

[cjf]

A quote from JA's measurements section of the Stereophile review of the XA25:

 

https://www.stereophile.com/content/pass-laboratories-xa25-power-amplifier-measurements

 

"the distortion did rise at higher frequencies, especially into lower impedance's. This graph suggests that the XA25 not be used with loudspeakers with an impedance that drops below 4 ohms in the treble."

 

XA30.8 would give you all you need or Used XA30.5....I owned an XA30.5 for a few months driving my Magico S3's and while I knew it would not be enough power I was more using them as a baseline on how big i needed to go within the Pass lineup. I was very impressed with how well they drove the total Pig's that the MKI Magico's S'3 are. I'm quite certain that they are worse than the Maggie's are in that department.

[cjf]

One thing I've learned the hard way in this hobby is to never again buy an amplifier that does not have a full set of test bench measurements available for viewing somewhere on the web; ideally by a trusted source other than the creator of the amp itself.

 

This is especially true if you have a pair of speakers that are more difficult to drive than usual. Panel speakers and others with similar load behaviors (Like the S3 mkI I currently own) at higher freqs can be a real bastard to tame for many Amps, especially Class D amps.. IME.

 

Below are just observations FWIW:

 

The AVA is not a Class D amp of course but the mention in one review of its use of Zobel networks somewhere in its design. These are often used to deal with high freq misbehavior. This would bring me pause if I were a potential buyer, especially given the speaker it would be paired with.

 

Its also a very small (physically) amplifier for its rated power output and there are no Specs at all on the product page. The question here then becomes, how much abuse can they take and how hot will they get. Just another thing that would bring me pause if I were a potential buyer.

 

In any case, if you get them hopefully none of the above observations will materialize into reality for you and they end up being great.

 

Best of luck in your search