Pass Labs XA 30.8 Stereo Amplifier

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Elephant321

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Pass Labs XA 30.8 Stereo Amplifier
« on: 23 Feb 2023, 01:11 am »
Hello, I've read this power amp gets a lot louder than it's rated 30 watts/channel(8 ohm) specs. Let me know your experiences with this XA 30.8 stereo amplifier.
Thanks,
Elephant321

2bigears

Re: Pass Labs XA 30.8 Stereo Amplifier
« Reply #1 on: 23 Feb 2023, 01:16 am »
 :D phone Pass ,  they will love to inform. Good guys for sure. Good gear.  :D

Stercom

Re: Pass Labs XA 30.8 Stereo Amplifier
« Reply #2 on: 23 Feb 2023, 01:31 am »
Loudness doesn’t determine sound quality but it can easily drive any reasonably sensitive loudspeaker to very loud levels.

newzooreview

Re: Pass Labs XA 30.8 Stereo Amplifier
« Reply #3 on: 23 Feb 2023, 01:45 am »
There is no standard for measuring maximum output from an audio amp. Many manufacturers will measure the maximum output before an unacceptable level of distortion occurs (e.g., 1% THD in some cases). Pass tends to state the maximum output, in watts, at the point where distortion starts to ramp up above its lowest levels.

In their review of the XA30.5, Stereophile noted

"While the XA30.5 may give 30Wpc into 8 ohms in class-A (14.8dBW), the distortion at this power level is low, at 0.015%. The amplifier doesn't actually clip (defined as the THD reaching 1%) until a much higher power level: 130Wpc into 8 ohms (21.14dBW)."

https://www.stereophile.com/content/pass-labs-xa305-power-amplifier-measurements

The 30.8 is likely to drive many speakers very well, but whether it suites your needs will depend on the size of your room, the listening volume you typically need at your listening position, the impedance curve of your speakers, and the efficiency of your speakers.

If you haven't used Class A amps before, it's also important to note that they run hot and need to have space all around them. The XA30.8 could sit on the top of a cabinet, but would need wide and high shelf space if on a shelf. It also needs to warm up about an hour to truly sound its best.

I own the XA25, the slightly lower powered sibling to the XA30.8. It sounds terrific, but when I tried a 300 watt per channel set of monoblock amps, the bass, which was very good, did improve. My speakers have two 15" mid and bass drivers, so having more power in reserve to move the cone mass seems to have improved transient response.

RDavidson

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Re: Pass Labs XA 30.8 Stereo Amplifier
« Reply #4 on: 23 Feb 2023, 06:24 am »
I’ve owned the 30.5, 30.8, and the XA25 among several other Pass /First Watt amps. I still own the XA25. It is my favorite of all of them overall. If you want big bass, the 30.8 is the ticket. 6 Moons characterizes the 30.8 as building its sound from the bass up. I agree with this. The XA25 is more even keeled and builds its sound from the midrange out and just sounds so natural all around. This past weekend I took my XA25 to a friend’s house and hooked it up to his KEF LS50 Metas. It is pretty well documented that the LS50’s will drink power all day long. The XA25 had ZERO problems. In fact we were all mind blown at how good that combination sounded. It was IMPRESSIVE. If you can, try the 30.8 and the XA25 at the same time. Unless you’re trying to drive super difficult speakers, either amp will have plenty of juice. It’s a matter of preference beyond that.

audiojem

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Re: Pass Labs XA 30.8 Stereo Amplifier
« Reply #5 on: 23 Feb 2023, 10:45 am »
Vandersteen Treo CT owner here I have driven them with a 30.8 and currently with XA25 both amps had no problem on the CT's.
I think the XA25 just disappears in my system.
As far as heat both amps run warm but do not heat up my small room I also don't play my music real loud.
Another + for the XA25 it's movable by one person which at 68 is nice!
Enjoy
AJ

Elephant321

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Re: Pass Labs XA 30.8 Stereo Amplifier
« Reply #6 on: 23 Feb 2023, 07:40 pm »
Thank you fellow members for some very intelligent input. My speakers are Audiovector R3 Signature(8 ohm), which are rated at 91dB sensitivity. My room is approx 12 X 18 feet. The speakers are 7 feet apart & my chair is 9 feet back. It seems the Pass Labs XA 25 may have enough power. The price difference between XA25 and XA30 is US 2,000, so my thinking tells me the XA30.8 is a safer bet. The other factor is that if my listening room were to change size in the future the XA30 would have enough power for a 35% bigger listening room. According to Pass Labs the XA30 weighs 88 lbs & XA25 weighs a mere 45 lbs.
Cheers,
Elephant321

Stercom

Re: Pass Labs XA 30.8 Stereo Amplifier
« Reply #7 on: 23 Feb 2023, 08:12 pm »
With 91db speakers the XA30 with its 30 watts can deliver 100db at 9 feet (your listening distance). The excellent sound quality, however, comes from the CURRENT those huge transformers and Class A topology deliver to the speakers. Thats why it weighs 88lbs and sounds great!  Here is the calculation:





RDavidson

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Re: Pass Labs XA 30.8 Stereo Amplifier
« Reply #8 on: 23 Feb 2023, 08:49 pm »
Do not judge the XA25 and 30.8 based on price. That’s a major mistake in this case, especially as their class A output is so similar as is their total power output. The XA25 has an entirely different circuit design (with unique output devices) compared to the rest of the Pass line. The only reason it is limited to the “entry” model is because they haven’t found a way to scale it up. I speak from A LOT of experience with Pass/First Watt amps and sensitive speakers. There’s a big reason the XA25 is my reference and the XA30.8 is not. The 30.8 is wonderful, and you may like it better, but do not judge based on price (and that blue meter :wink: that we all know is what you’re really lusting after). Some additional considerations : Heat and noise floor. The XA30.8 is large and heavy for a reason. It doubles as a space heater and will raise your room’s ambient temperature ; The XA25 not nearly as much. Regarding noise floor, the XA25 is significantly quieter. With my Omegas I could always hear some light hiss with the 30.8. This may not be as big of a problem with your speakers or other multi-way passive speakers with crossovers. Here’s a recent relevant review from a guy who has even more experience with Pass / First Watt than me. He directly compares the XA25 with the 30.8. https://darko.audio/2023/02/pass-labs-xa25-review/
« Last Edit: 23 Feb 2023, 10:04 pm by RDavidson »

Chazz5

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Re: Pass Labs XA 30.8 Stereo Amplifier
« Reply #9 on: 23 Feb 2023, 09:53 pm »
I got the FirstWatt F8, nominally 25 watts into 8 ohms, at a discount for a "demo" that I could not visually tell from a brand new piece.

Works great, fed by Van Alstine's Transcendence RB-10 tube preamp. Neutral yet musical, all the detail I can imagine is in the source.

I listen at lower-middle volume and rarely turn the preamp volume control past 11 p.m. Speakers are Focal Aria 906's.



RDavidson

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Re: Pass Labs XA 30.8 Stereo Amplifier
« Reply #10 on: 23 Feb 2023, 10:18 pm »
The only thing First Watt amps generally lack is the all out power and scale of bigger Pass amps, which is understandable because their power supplies are significantly smaller by design. It’s a parameter that Nelson set as a constant in his experiments. However, I think transparency and purity are gained with these smaller (perhaps simpler) circuits. It’s akin to comparing a small SET tube amp to a big push/pull tube amp from the same manufacturer. Both amps are wonderful for their intended use and some will favor one over the other for various valid reasons. Or if you’re like me, own several amps and swap them and enjoy them when the mood strikes, if you can. Why live with only 1 amp when there’s so many great choices that perform differently, but in equally enjoyable ways? :D