Pass Labs xa - .5 amps

Has anyone compared the new Pass XA-30.5 stereo amp to the XA-60.5 mono amps? Interested to hear your impressions. I am considering one (or two) these for use with my ML Vantage speakers. Thanks.

Bob R.
I have. The stereo amp is a real sweetheart, and packs more punch than you would believe for 30wpc. I bought the XA-60.5 because I wanted more power, but honestly, I think the XA-30.5 is a little sweeter sounding in the highs provided you don't push it to it's limit.
With the XA30.5s ability to deliver current and the sensitivity of your speakers, I would think the 30 watts would be more than enough for most listeners in most rooms. As Tvad says, it plays a lot louder and more robustly than its wattage specs would suggest (I think it is very conservatively rated). The extra 30 watts of the XA60.5 are really marginally more power in terms of loudness. And I'm firmly in the camp that less power will sound better if it is enough power to drive your speakers to the volume levels you require. I was using the XA30.5 with my 89db Merlins and power was NEVER an issue. With your speakers and 4ohm impedance, I would not expect power to be an issue for you either. Now you may hear from those that say you can never have enough power.... Ask ML what they think and ask Pass what they think. Can't speak for ML, but I've never known Pass to not offer good, honest advice, even if they prefer to sell you two amps instead of one.
Thanks for your responses. I ordered an XA-30.5 - can't wait for it to arrive. My dealer has a 6-month full credit trade in policy just to tempt me to upgrade to the XA-60.5.
Congratulations. I think you have a very, very fine piece. Some might argue the best sounding amp out of the Pass shop (assuming sufficient power of course).
Anyone compared the XA-30.5 to the Aleph 3? I had an Aleph 3 and an Aleph P many years ago and thought the combination was fantastic. I sold the Aleph 3 because I purched new speakers that required more power. Somtimes I wish I still had the Alpeh 3 and other speakers.
I imagine the xa-30.5 is a more dynamic with wider soundstage and better grip on bass. I would like to trade my aleph 3 for one but my budget will not allow it right now. I wonder how it would compare to a first watt aleph j? one thing tho I would have to agree with Pubul57 about low power amp sounds better. I listened to a friends aleph 1.2, it sounded nice & sweet but didn't seem to sound as sweet as my aleph 3. maybe it has to do with more transistor in the signal path or something, it did not sound as pure as the low powered aleph. I also listen to a pair of bk mono blocks that were 200 wpc and, if did not sound a good as my aleph 3, or the aleph 1.2. I have been wanting to listen to aleph j but don't know any near me to compare and when I read the review on 6 moons on the xa-30.5, I have been drooling over the xa-30.5
I'm not a believer in the blanket statement that lower powered amps always sound better. In my experience amps should be reviewed case by case. While I have heard some lines of amps where a lower powered one sounded better to my ears, I have also heard the opposite to be true. All other things equal, I think higher powered amps do have their advantages.
I owned the Aleph 3 and 2 and I think the XA is more dynamic, and obviously so. I owned the Alephs so long ago that I can't say more about other specific comparisons, but the XAs are real current monsters and they have a lot of bass drive and pace. The high power/low power argument is proabably endless and subjective to some extent, but I still think that the same basic circuits with the differences based on output power will sound better IF the lower power is sufficient to drive the speaker to the right levels. IF not, than more power will have an advantage since insufficient power is proabably more of a liability than the benefits of the simpler lower power version of an amp. But I don't mean to sidetrack, other than to agree that overall the XA is an improvement over the Aleph in that it maintains the former's virtues while adding improved bass and dynamic performance (the Aleph is still a great sounding amp, and with certain speakers the difference in drive might not even be noticeable)
Well the XA-30.5 is here and it sounds wonderful - powerful, punchy, and very transparent. It's been running for about 5 hours now and I've noticed marked improvement just in that period of time - thin and bright when I first plugged it in, but that's all but gone now. I'm sure the buck-a-foot Monster Cable that I'm using isn't helping matters any (the only able I had with spade connectors.)

Any recommendations for speaker cables?
Leave it in standby between use.

Do not power it down.

Have fun.
I used a Nordost Hemindall speaker cable with Focal Electra 906 and Pass X2 pre. and run very well, but im searching a Xlr cable between pre and power, ideas?

Im think in focal micro utopia but are a 89 db what do you think?
At the moment have a loaner XA 30.5 hooked up to my Lohengrin.
with 95 Db it get's to really excessive spl's.
just amazing what this little Pass does concerning control and sheer power.
very new so cannot make claims on musicality, but i like it. remember it's all in the match.
Anyone using this XA 30.5 with 4 Ohms (86DB) spekers?
I am highly expected your suggestion becoz am planned to purchase the same for my Dynaudio Speakers.
The XA-30.5 will be fine with 4 ohm speakers, but it might not deliver the volume you require on 86dB speakers unless you are in a small room and listen at low volume.
Thanks for the suggestion and presume 280 sq.ft room can be it?
Really depends on how loudly you listen. The XA-30.5 will run out of steam at 100dB peaks on your speakers.
Thanks and I feel this 100db peaks is enough for me.
hi, I have revel f32 speakers with a rating of 87 db , and a nominal impedence of 6 ohm , with a dip down to 3.5 ohm at 250 hrtz, can someone tell me what that translates to as far as db with a pass xa 30.5 or a pair of xa 60.5 ? I have a small room 12x16 . thanks chrissain
Hi, These days am really enjoing with the new amp of xa30.5 with dynaudio (4Ohms/86db) speakers. Really worth to buy this amp. My room size similar to mr.chrissain room size which is 12x16.
The Pass XA-30.5 is a terrific amp. Glad to know you're enjoying it, Rabbani.
Lots of Pass fans here. I haven't heard the XA30.5 or XA 60.5 but I had the Aleph 3, 5, 2, XA 160 and now have the XA 100.5. Sorry if this post deviates a little from the origial question.

With the exception of the Aleph 3, all of these amps drove my Eggleston Rosa which is 87dB, 6 ohm nominal and 4 ohm minimum. My room is 16.5' X 15.5' X 7.5' for a total of 1918 cubic feet. I find the XA100.5 to be by far the best of the Pass amps that I have had in my system. Having gone from 30 watts to 60 to 100 to 160 and back to 100, I have concluded that in my room with my speakers the extra power made a very noticable difference, especially the extra current and doubling of power with the halving of impedence of the XA.5 - 200watts at 4ohm load.

The impovement is in greater ease and flow of the music and much better grip and impact of lower frequencies. The noise floor is lower and focus/staging are better, but this is because of the improved circuit, not power I think. Also everything became quicker. If I could have afforded the XA160.5, that would have been even better at 320watts at 4ohms. The Egglestons love power, even in my small room. I listen at an average 85 dB with peaks above 100dB.

Having said all that, I bet the XA30.5 with a 91+dB efficient speaker would sould incredible. Hope this helps and congratulations.
I wouldn't hesitate to use the XA30.5 with 89db in most rooms, more than enough power and drive with my speakers. I think these things are very conservatively rated, at least, the sound that way. To me, less powerful versions of a cricuit always sound better, assuming the power is sufficient to drive the speakers. Less is more in many cases.
I am also looking at purchasing a Pass XA-30.5. Anyone have thoughts or experience with a Conrad Johnson ACT 2.1 and the Dynaudio Sapphires? Sapphires are rated sensitivity specified as 88dB/2.83V/m. Room is small in nature 11 X 13 X 9.

Also, I'd like some thoughts on moving from a Sim Audio Titan to this particular amp for 2 channel listening. If anyone would care to comment I'd greatly appreciate it.

Mozvz, I believe the XA-30.5 would be a nice match for your speakers, your room, and your preamp.
I have ran a Conrad Johnson CT-5 into the 30.5 with excellent results. I've heard many combinations during my time in this hobby and this is one of the best if not the best I have heard. Liked it so much, I got the 100.5's a few weeks ago and will take delivery of the ACT 2.2 next week. I can only imagine.
FWIW, used X-600.5's might be had for close to the same cost as new XA-60.5's. Almost the same amount of Class A operation, but with a whole lotta extra head room.
>>03-06-09: Mozvz
I am also looking at purchasing a Pass XA-30.5. Anyone have thoughts or experience with a Conrad Johnson ACT 2.1 and the Dynaudio Sapphires? Sapphires are rated sensitivity specified as 88dB/2.83V/m.<<

I have a pair of Sapphires here paired up with XA100.5. Don't even consider an XA30.5 with this speaker. You'll be very disappointed.

Dealer disclaimer- both brands.
Don't even consider an XA30.5 with this speaker. You'll be very disappointed.

Dealer disclaimer- both brands.
Audiofeil (Threads | Answers)

Why? Volume, tonal balance or both?

The OP has a small room.
The amp will run out of horsepower IME.
Generally, I agree. However, due to the 11 x 13 room, it may still work depending on the OP's preferred listening volume.

As long as he doesn't exceed 100dB (16wpc), he should be OK, don't you think?
Based on my experience I don't agree.

03-07-09: Audiofeil
"Based on my experience I don't agree."

Thanks for providing feedback gentlemen. Actually, I do not listen at high volumes, yet at the same time, it would be better to have more headroom then a lack of it??

The mono blocks (60.5 through 200.5) are out of question due to floor space constraints. If the XA 30.5 will not drive the speakers appropriately, then I would be better off with a 250 X250.5 or the 300 series?? Different flavor of amp I assume?

I am currently using a Sim Titan 7 channel. Do you gentlemen think the Pass would be worth the upgrade or would the Sim to the Pass be a lateral move?
Here's the answer. Audition the XA-30.5 in your system. It's the only way you'll know if it works for you.
Currently I am using Dynaduio 4Ohms speakers for this new XA 30.5 amp and Any one can tell me or suggest other
than Dynaudio, Which is the best matching speakers for this amp? Most suggestion from above recomending morethan
89db speakers will work suitably but no one was not specified, which manufacturare speakers will work better way?
I haven't listened to the X250.5 or X350.5, but I own the XA 60.5. The pair of 60.5 sit on stereo rack. So it does not matter to me if I have 1 or 2 amps. The reason I write is that I don't think I'll ever come back to Class AB amp. after living with Class A amp. The mid-range is more much natural, meaning less harsh and more fluid. Sound texture is far more realistic. To me the sound of each note, let it be vocal or instrumental, is a continuum of frequencies with the dominant ones being more present and hanging around a little longer. The subtle frequencies thus have shorter transient. Class A amp., at least the XA 60.5, let me hear the whole spectrum of frequencies as opposed to mainly just the dominant frequencies. The result is a truer sound.

From the power standpoint, 60 watts/channel means 120 watts for my full-size speakers. The pair of XA 60.5 are actually more dynamic, with that headroom you are talking about, producing more slam yet distinctive drum bass than a 150/300-watt amp. they replaced. To avoid talking down on a well respected amplifier, let me say that this former 150/300-watt amp. of mine came highly recommended by Stereophile who put it in their Class A category (this is review rating, and is not the "Class A" amp. I referred to earlier). Now that should tell you something about the XA 60.5.

Thank you for the detailed and informative analysis of the Pass XA 60.5. Posts such as you write are extremely helpful for someone like me. As Tvad has stated, the best case scenario is to bring these amps into your home and audition them to experience their synergy with your room and equipment. Unfortunately unless we are blessed with a local, extremely accommodating dealer, or have the luxury of large funds, many times it's reading posts such as yours that can provide some clarity in a decision making process.

Thanks again!!
Unfortunately unless we are blessed with a local, extremely accommodating dealer, or have the luxury of large funds...
Mozvz (Answers)

First, let's assume since you mentioned you are considering purchasing an XA-30.5 that funds are not an issue.

Second, contact Reno HiFi and see what you can work out regarding an audition.
If you choose to buy a brand new pair of XA60.5, it will set you back around $11K. To be fair I must preface that my earlier comment implies proper caliber for the remain equipment right down to cables and connectors. I should also said that the surprising factor, in my case, is actually the vibration/isolation platforms. It's like getting an upgrade on your equipment if you choose the right platform. It's comical that the platform I used under my power conditioner costs twice as much as the power conditioner itself. Yet that's the add-on that makes the most difference. Just about everything would have to be "right" to avoid wasting money on buying the XA60.5 or any amplifier with this level of performance.
Funds are always an issue in my case. I consider the Pass product line because I have another piece of equipment that I can trade or sell to use as some of the funds for the purchase. Thank you for the tip on Reno HiFi

You are correct about the price of the 60.5's and yes, they are costly no doubt. I understand your comment about proper equipment, cables and isolation devices and wasting money on an amp that does not fit into the entire synergy of the complete system. Getting everything right is part of the process no doubt.
I second Tvad's suggestion to contact Reno HIFI. If you do not have a local dealer to audition the amps directly, Mark at Reno is an excellent option. His prices are fair and he allows in-home auditions for 30 days. He is very pleasant to deal with, but he is not local.

Sorry I did'nt see the second part of your original post. As far as speaker cables are concerned, Pass recommends short lengths and thick cables with their amps. I use Harmonic Technology Pro 9 plus cables 1.5 meters long as recommended by my dealer, and they work great with my XA100.5s. With monoblocks you can use shorter cables by placing the amps just behind the speakers, but my dealer recommended nothing shorter than 4-5 feet. Hope that helps.
Class A operation surely does seem to have it's benefits, but, let's not credit all an amplifiers apparent prowers to this aspect of it's design alone.
I will contact Reno Hi-Fi. Honestly, I am still sifting through various questions in my mind and will make a decision in the next few days.

I've never owned a Class A only amp. I've had A/B's and D's. I know the Class A gets rather hot, but only from others comments about them. When they are in standby mode, do they generate a tremendous amount of heat or once they are powered on, the heat increases substantially?
My XA-60.5 get warm, but they do not get hot.

You couldn't make a melted cheese sandwich on them.
My XA100.5 is room temp in standby mode, warm after powered on, slightly warmer after a few hours of music. The XA160 was warmer still, but never hot, the Aleph 2 was VERY HOT. There was a photo circulating on the net of the Aleph 3 with a fried egg on top of it.
Hey Tvad, do you find having to wait some 3-4 hours from standby to fully power on mode before your XA 60.5 reach their full potential. May be I'm being too picky, but the half to one hour warm up just isn't enough.
03-09-09: Spatine
Hey Tvad, do you find having to wait some 3-4 hours from standby to fully power on mode before your XA 60.5 reach their full potential.

No. I enjoy them immediately.
Hi Tvad, I have small doubt on the meter in front side.
My previous amp xa 60 needle was staybale but xa 30.5 needle always moving around, why? secondly this amp is not single ended class a? can you please clear my doubts?
I don't believe the XA-.5 series are single ended Class A. There are very few single ended Class a solid state amps. I believe the First Watt is one.

Here's a white paper about Single Ended Class A written by Nelson Pass, the designer of the First Watt.

I think if the A-30.5 needle is moving around that you might be exceeding it's power limits. Not sure, though. You should contact your dealer for further info.
Seems to me that Audiofeil might be in the position to offer the best advise on this one.
Unlike most amplifiers the meter staff on the XA.5 series indicates bias, not power.

It will move only when the amplifier exceeds its' rated output.

Dealer disclaimer.