Pass Labs XA-30.5 or X150.5? (What would you choose?)

76.24.78.116

Posted on April 25, 2012 at 14:04:59

Freo-1
Audiophile

Posts: 1327
Location: Florida
Joined: June 14, 2008

Recently, obtained a pair of Cary Silver Oak Model One speakers. They are outstanding performers. The Cary's come equipped with 2 SEAS Excel Magnesium woofer/mid drivers per side, along with SEAS Excel soft dome tweeters. They are 88db@1 watt.

So, the question I had to answer was: Go with the XA 30.5 or X 150.5? After careful deliberation, decided to go with the XA 30.5. Although it's rated at 30 wpc @ 8 ohms, the power supply can deliver quite a bit more than that. I always have preferred a Class A amp to class AB, provided the speaker can support the lower power.

So, looking for feedback here. Which amp would you pick, and why would you pick one over the other?

" Don't look back. Something may be gaining on you"

Satchel Paige

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RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

pictureguy

11:37:28 09/06/16

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Frihed89

03:51:29 04/27/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Freo-1

15:07:55 04/27/12

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RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

pictureguy

11:37:28 09/06/16

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Frihed89

03:51:29 04/27/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Freo-1

15:07:55 04/27/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Freo-1

12:24:28 05/04/12

About your Pass Labs XA-30.5

cin5

22:05:19 08/28/16

Late to the party but agree with the others...

Eddieh

15:15:17 04/26/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Freo-1

13:06:47 04/26/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

AbeCollins

13:53:48 04/26/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

pictureguy

14:34:41 05/04/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Freo-1

05:35:52 05/05/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Freo-1

14:17:35 04/26/12

I too chose the Pass Labs XA-30.5....

Tubo

08:45:42 04/26/12

RE: I too chose the Pass Labs XA-30.5....

Ozzie

19:09:03 04/26/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

lochrider

05:56:35 04/26/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Freo-1

13:13:13 04/26/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Justlisten2

22:45:44 04/25/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

hahax@verizon.net

20:29:29 04/25/12

Just Be-aware of the HEAT from Class A amps

Dynobot

18:20:30 04/25/12

This Class A frying pan ?

AbeCollins

18:55:59 04/25/12

RE: This Class A frying pan ?

Ozzy

11:31:36 04/26/12

RE: This Class A frying pan ?

AbeCollins

13:50:50 04/26/12

RE: This Class A frying pan ?

Dynobot

19:20:23 04/25/12

Good luck

AbeCollins

18:04:07 04/25/12

RE: Good luck

pictureguy

09:29:32 05/05/12

RE: Good luck

Freo-1

09:51:03 05/05/12

RE: Good luck

pictureguy

12:42:49 05/05/12

RE: Good luck

Freo-1

13:52:12 05/05/12

Class A power ...

TBone

15:58:08 04/26/12

always pick the better amp

Penguin

17:40:04 04/25/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?)

Mechans

17:28:51 04/25/12

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on April 25, 2012 at 17:28:51
Mechans Audiophile Posts: 1804 Location: East Coast Joined: May 23, 2004	I guess it will depend on the reactance of the Cary speaker load to see if the class A amp does its thing. Otherwise although unlikely I suppose there is a concern that you won't be able to drive them to high volume in a large room. But remember the best amp in the world is the amp you like the best. I also have a thing for Class A amps but currently only own a Jadis Class A tube amp.

always pick the better amp , posted on April 25, 2012 at 17:40:04

Penguin
Audiophile

Posts: 7116
Location: Delaware
Joined: August 5, 2001

that will play loud enough with your speakers.

If you are listening at 15 feet from the speakers that is a 6 db drop in sound pressure, so you would get about 82 db at that point from 1 W. Based on that 32 W gives you another 15 db which bumps you back to 97 db at 32W, double the power and you have 100 db pretty damned loud in a room. in contrast you would get another 3 maybe 5 db out the X150.5 :) Is the extra 8 db (over the 30W class A) worth the sonic differences between the two amps? IMHO the XA amps are just much better than the X amps. Not to knock the X, the X is a super nice amp it is just the XA is much more refined.

If you have the chance listen to both and you decide :)

dee
;-D

True terror is to wake up one morning and discover that your high school class is running the country.

quote by Kurt Vonnegut

Good luck, posted on April 25, 2012 at 18:04:07

AbeCollins
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Since: February 2, 2002

Class A is nice but only if the power is sufficient for your speakers.

I have a pair of Tannoy Definition D500's rated at 91dB sensitivity & 6 ohm nominal, a supposedly easy load. Unfortunately, the 30wpc Pass Aleph 3 and the newer Aleph 30 "Volksamp" never really lit up these speakers. The sound was a little veiled and compressed at barely normal listening levels... and somewhat congested when attempting to play a little louder.

I also owned the Pass X150 and X150.5. These brought real life and dynamics to my speakers and were a much much better fit for my "efficient" Tannoys.

Just Be-aware of the HEAT from Class A amps, posted on April 25, 2012 at 18:20:30
Dynobot	I think Abe can elaborate more on this with his fry pan pic. I had to get rid of my ClassA monoblocks because of heat issues. Just too hot for my room.

This Class A frying pan ?, posted on April 25, 2012 at 18:55:59

AbeCollins
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Posts: 46280
Location: USA
Joined: June 22, 2001
Contributor
Since: February 2, 2002

250-watts of constant power sucking, heat producing, egg frying, Class A amplification.....

And that's 250-watts just sitting idle not playing any music. The other downside I found was that my Class A amps required a good amount of warm-up time before they sounded their best. So that meant, A)Leaving the amp on all the time, which I wasn't willing to do, or B)Powering up the amp and waiting an hour before I could really begin to enjoy the music.

And the X150.5 that I actually preferred in my setup

RE: This Class A frying pan ?, posted on April 25, 2012 at 19:20:23
Dynobot	Nice looking amps though. I tried to leave mine on 24hrs because they sounded best when they were nice and warm too. Imagine Georgia heat in August with two Class A monoblocks drawing 300watts idle in a smallish room.

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on April 25, 2012 at 20:29:29
hahax@verizon.net Audiophile Posts: 4306 Location: New Jersey Joined: March 22, 2006	I believe the XA-30.5 actually produces a lot more than its rated power but it goes out of class A when it does. So you have a fair amount of head room for peaks. And it's usually the peaks that cause the problem. Most of the time you listen at a couple of watts on average(unless you listen to compressed rock at concert levels).

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on April 25, 2012 at 22:45:44
Justlisten2 Audiophile Posts: 1266 Location: SE PA Joined: March 8, 2001	I also enjoy Class A amps over Class AB. That said, 30 wpc is rather low. Though at 88 db sensitivity, your playing at 98 db with 10 wpc. I would say it would depend on the size of the room. If the room is small to moderate I'd probably go with the XA 30.5. In a larger room I'd probably go with the X 150.5. My Coda Model 11 amp puts out 100 wpc of Class A power.

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on April 26, 2012 at 05:56:35

lochrider
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Posts: 493
Location: Southeast Minnesota
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Contributor
Since: March 17, 2002

I had the X-250.5 stereo amp and now have the XA-100.5 mono blocks. My speakers are rated at 87 dB @ 1 watt, 6 ohms, and present a very easy load at the low end due to an on-board LF amplifier. I listen at average levels from 70 dB to 85 dB at just over 10 feet from each tweeter in a room with more than 2700 cubic feet.

My experience is that the Pass X.5 amps are very good to excellent with very dynamic music played at what I consider to be loud levels (85+ dB) and offer some very nice sweetness at lower listening levels while they operate in class A. I never noticed any point where the X.5 transitioned to class AB from class A operation, nor was there any glaring deficiency in the X.5 performance.

I hesitated at some length getting the XA.5 mono blocks due to anxiety about the heat they may generate. This turned out to be a non-issue in my room.

What I got with the XA.5s was transcription of the texture and tone of acoustic instruments and voice from the very softest to the loudest listening level with no perceptible decrease in impact with my speakers in my set-up. Also, the XA.5 presented a more entertaining soundscape with beter localization, placement and body of instruments and voices in all genres of music. I am very happy I went with the XA.5s.

You might or might not need more power with the Cary's; I am not familiar with them.

******After re-reading your post I realize you've already decided, but you don't say whether you've got the XA.5 in house. I, frankly, do not understand why on earth you care what others think if you've already decided. Anyway, have fun.

Cheers,

Ian

I too chose the Pass Labs XA-30.5...., posted on April 26, 2012 at 08:45:42

Tubo
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Posts: 375
Location: So. California
Joined: June 9, 2004

to power my 4-ohm Magnepan MMG's. At 4 ohms I get 60 watts in Class A and 200 watts in Class AB. I have never heard any clipping and only occasionally seen the meter needle jump past the twelve o'clock position. My understanding is that the noon position marks the transition between Class A and Class AB. My system sounds great with these amps!

At 8 ohms you probably have around 100 watts available in Class AB. Should be enough headroom. Enjoy!

RE: This Class A frying pan ?, posted on April 26, 2012 at 11:31:36
Ozzy Audiophile Posts: 7588 Joined: September 21, 1999	>Powering up the amp and waiting an hour before I could really begin to enjoy the music.< That includes any amp I have ever owned. Oz Don't worry about avoiding temptation. As you grow older, it will avoid you. - Winston Churchill

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on April 26, 2012 at 13:06:47

Freo-1
Audiophile

Posts: 1327
Location: Florida
Joined: June 14, 2008

Thanks everyone for all the great feedback.

Decided to get the XA 30.5. It should show up the middle of next week. The dealer will give a ten day trial period to make sure that the amp will work well with the target speakers and listening room. If for some reason it seems that more power is required, then the XA-30.5 can be swapped for a X 150.5.

Based on use with a Threshold SA/3 on the Cary speakers, believe the XA 30.5 will work just fine.

" Don't look back. Something may be gaining on you"

Satchel Paige

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on April 26, 2012 at 13:13:13
Freo-1 Audiophile Posts: 1327 Location: Florida Joined: June 14, 2008	Good quetion, Ian. The primary reason is that I have a trial period where if the XA 30.5 seems not to have enough power, then I can swap it for a X 150.5. Besides that, getting feedback on the tow amps is always welcome. :-) " Don't look back. Something may be gaining on you" Satchel Paige

RE: This Class A frying pan ?, posted on April 26, 2012 at 13:50:50

AbeCollins
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Contributor
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"That includes any amp I have ever owned."

That includes some other amps that I have owned but not all of them.

Some you simply turn-on and listen (Class D amps), others require maybe 15 to 20 minutes, but Class A solid-state required a very long warm up time in my experience. The Class AB SS amps not as much.

I also found tube amps to actually require less warm-up time than SS Class A amps. Just guessing but it might have to do with less thermal mass to stabilize, or not. Just my experience with the gear I have owned over the years.

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on April 26, 2012 at 13:53:48

AbeCollins
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Will there be any opportunity for you to try both the XA-30.5 AND the X150.5 before making a final decision?

I understand that the XA-30.5 has lots of power supply so you might be OK. In my case, I was comparing the Pass Aleph 3 and 30 (volksamp) to the X150.5. In this scenario the X150.5 was the clear winner by a huge and very noticeable margin, even on my "easy to drive" Tannoys.

Please let us know how it works out with the XA-30.5. Enjoy!

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on April 26, 2012 at 14:17:35

Freo-1
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Posts: 1327
Location: Florida
Joined: June 14, 2008

Not side by side. I had a First Watt M2 (which I think is similar to the Volksamp), and yes, you would be right to cite the X 150.5 as a clear winner.

The dealer stated that the X 150.5 would be more accurate compared to the XA 30.5, BUT, the XA 30.5 would be a bit warmer sounding, which many people equate to being closer to live music.

What size room is your listening area? That could play into the overall equation as to what would work better with a given speaker. The Cary’s are supposed to be a easy load to drive, as Dennis Had designed them to work with lower wattage tube amps. Given that they are only 88 db@ 1 watt, I find that a bit curious.

What I can tell you is that the SEAS Excel drivers are outstanding. The clarity from the speakers was a remarkable revelation to me.

" Don't look back. Something may be gaining on you"

Satchel Paige

Late to the party but agree with the others..., posted on April 26, 2012 at 15:15:17

Eddieh
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Posts: 297
Location: Canada
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I had the X250.5 with my modded Maggie 1.5qrs and it sounded great. Never moved the needle at all so I tried the XA30.5 and it had all of the attributes mentioned by the others - more refined texture of instruments, better soundstage, etc. Also, the needle only moves off idle when I play old Yes albums fairly loud, so for my room (smallish) even the low efficiency of the Maggies does not present a problem.

Enjoy your amp, she's a beaut!

Class A power ..., posted on April 26, 2012 at 15:58:08

TBone
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>>Class A is nice but only if the power is sufficient for your speakers.<<

It really is speaker dependent ... but my Classe DR3s are rated at 100w per channel mono (100w/8ohms, 200w/4ohms). My last three amps, all nice Class AB models, were rated at 150w, 150w and 200 watts per channel ... yet as good as they were (and they were very good) none seem to deliver the kind of "musical power" that my Class A amps routinely attain.

tb1

RE: I too chose the Pass Labs XA-30.5...., posted on April 26, 2012 at 19:09:03
Ozzie Audiophile Posts: 3814 Joined: August 1, 2002	I have an old 40 watt Class A Forte 4 on my mini Maggies in the upstairs rig. Like you Tubo, I'll never drive those little guys any other way. Beautiful beautiful mids.

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on April 27, 2012 at 03:51:29
Frihed89 Audiophile Posts: 15703 Location: Copenhagen Joined: March 21, 2005	I suspect that you can drive your speakers to ear-shattering levels with the smaller amp, even in a moderately sized room, and still be using about 1W!

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on April 27, 2012 at 15:07:55

Freo-1
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Posts: 1327
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Well, I get your point, but not exactly.

If the speakers could deliver ear shattering levels at one watt, then I would have kept the First Watt M2. The XA-30.5 has about 6 times the power supply reserve compared to the M2 (which is 25 watts @ 8 ohms and 40 watts @ 4 ohms.)

I’ll be able to judge when the amp gets here and I see what the current meter does when playing various types of music.

" Don't look back. Something may be gaining on you"

Satchel Paige

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on May 4, 2012 at 12:24:28
Freo-1 Audiophile Posts: 1327 Location: Florida Joined: June 14, 2008	The amp arrived this week. So far, very impressive indeed. Do not feel the need to have any more power with the 88db@1watt speakers the amp is pushing. The depth and clairy of the sound is truly remarkable. The XA 30.5 is a great product. " Don't look back. Something may be gaining on you" Satchel Paige

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on May 4, 2012 at 14:34:41

pictureguy
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Posts: 22597
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Joined: October 19, 2008

As nearly as I can tell, based on pictures, tests, WEIGHT, #of output devices and other info, the 150 and the 30.5 are 'kissin cousins' differing mainly in the bias supply and settings.
Of course, they are biased differently, go out of class 'a' at different power outputs and have different maximums, but they are cousins nontheless.

Of note is that Pass makes 2 integrateds....one based on the 30.5 and the other on the 150. hmmmm. I'll bet 50 pesos those amps are about 80% in common between 'em.

Until I can afford one (gasp!), I'm not going to worry about the audible differences under my conditions. I'd like to try 'em both, though. Reno HiFi recommended the 150 for my low-sensitivity panels, however, FWIW.
Too much is never enough

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on May 5, 2012 at 05:35:52
Freo-1 Audiophile Posts: 1327 Location: Florida Joined: June 14, 2008	I think that they are very close indeed. Papa more or less followed that model with the Threshold S300 and SA/3. Those were basically the same amp, just used different voltage rails and bias points. I converted a pair of S300’s to SA/3, and have been very happy with the results. " Don't look back. Something may be gaining on you" Satchel Paige

RE: Good luck, posted on May 5, 2012 at 09:29:32

pictureguy
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Posts: 22597
Location: SoCal
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I keep reading about 'fit' and that some amps of a given power work better than the same power from a different manufacturer.
I think I may know WHY, if you are curious.
Speaker load is not only impedance but phase....current and voltage 'out of sync'.
For more detail, look up 'power factor'.

Anyway, all amps are not created equal even if they measure the same into a resistor.
Throw +-45degrees at 4 ohms or even 2 ohms at 'em and watch the differences appear.

Maybe the 91db Tannoys simply are a load which have high reactance at a frequency with low impedance, too. That combo will really test an amp and bring the real players to the front.
Too much is never enough

RE: Good luck, posted on May 5, 2012 at 09:51:03

Freo-1
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Posts: 1327
Location: Florida
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The speaker load definitely has an effect on overall amp/speaker performance. In my HT rig, the 93 db@1 watt Legacy Signature IIIs simply did not work very well with a HK Citation II, which should have been fine. The speakers came alive when I switched to a pair of Threshold SA/3 using a vertical bias setup. The difference in impendence with that speaker bi-amped is significant.

The Cary Signature Oak Model Ones are a easy load for the XA 30.5 (not a large swing in impedance), and provides some outstanding sound as a result.

" Don't look back. Something may be gaining on you"

Satchel Paige

RE: Good luck, posted on May 5, 2012 at 12:42:49

pictureguy
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Posts: 22597
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Even low sensitivity speakers / low impedance speakers can be an easy load......
Like Magnepan.
The 3.6, for example drops to only 3.3 ohms while never being above about 25degrees, even at the highest audible frequencies. EASY, electrically, for any competent amp.

The killer, once again, is PHASE. Basicallly, a measure of how inductive or capacitive a speaker is.
Measured in Degrees, you can calculate how much power is NOT delivered or able to be delivered to the load by this means.

You get BILLED for watts but use VA. Your amp is rated in WATTS, but the VA ability at frequency / impedance / phase is far more important.

Please see the attached link for a proposed method of amplifier measurement.

If you amp can't deliver the goods into the presented load, or rather is a good room heater, no amount of power will really help.

I'd have thought better of the Citation.
Too much is never enough

http://www.audiograph.se/Downloads/PowerCube_12p_brochure_co

RE: Good luck, posted on May 5, 2012 at 13:52:12

Freo-1
Audiophile

Posts: 1327
Location: Florida
Joined: June 14, 2008

The Citation II is a fine amp, no question. The Legacy Signature IIIs are a tough load, especially if a single amp is used to drive them as opposed to bi-amping. The Threshold SA/3 handles the speaker better, especially when vertically bi-amping, as the impendence of the amp changes for the better when bi-amped (Not to mention the elimination of the back EMF).

The Pass Labs XA 30.5 is driving the Cary Signature Oak Model One speakers VERY nicely. Papa Pass knows what he is doing, and I would rank his amps among the very best when connected to difficult loads (which the Cary's are not).

Interesting link.
" Don't look back. Something may be gaining on you"

Satchel Paige

About your Pass Labs XA-30.5, posted on August 28, 2016 at 22:05:19

cin5
Audiophile

Posts: 39
Location: Long Island
Joined: August 17, 2015

Congrats on getting the Pass XA30.5! I'm thinking about one, but it would be a big help if you would reply to these questions:

Did you always keep the amp in the Standby mode when not playing music?

How long did it take for the amp to sound its best when you took it out of standby mode?

If more than one, which makes/models of speakers did you use with this amp?

When it was ready to play music did the amp always stay hot to the touch regardless of the speakers you used?

Which, if any speakers, did NOT have the most impressive midbass and/or bass response with this amp?

Unless you have a large room and/or often play at loud levels, which, if any, speakers made the amp's ammeter move about 1/4 to 1/2 inch away from the center?

Did you always put the amp in standby mode when not playing music, or did often power the amp off with the rear chassis switch?

I'm in New York. Would you know anyone who has the XA30.5? I'd love to hear it.

Best Regards,

Greg

RE: Pass Labs XA-30.5 or X150.5? (What would you choose?), posted on September 6, 2016 at 11:37:28
pictureguy Audiophile Posts: 22597 Location: SoCal Joined: October 19, 2008	The XA30.5 has NEARLY 6db of headroom against the rated 30 watts. By that point it is running A/B and distortion starts to rear its ugly head. If I Had the COIN, I'd use a pair of the XA30.5s as biamp for my Maggies. The addition of a line level crossover would net a near 3db additional power and that's IT. Too much is never enough

Amp/Preamp Asylum

Pass Labs XA-30.5 or X150.5? (What would you choose?)

76.24.78.116