My earlier comment about sound superiority when compared the XA60.5 against a Stereophile Class A amplifier was based on using single-ended connection. My preamp is also in the Stereophile Class A category. Its manufacturer has a radical viewpoint that balanced connection does not make a difference in light of their well crafted circuitry. So back then there was that lingering thought about perhaps my preamp could be eclipsed by an different preamp of equivalent pricing but with balanced connection. I am known to be picky and difficult on just about anything, even as my preamp sounds pretty good and is well respected by enough professional reviewers. Yet after getting the pair of XA60.5 and am so surprised at their performance, I have resigned my concern.
The point here is more about Class A amplifier than about Pass Lab. I just dive right into Pass because they are the measuring stick and the bridging gap when people attempt to compare solid state amplifiers to tube amplifiers, with each category having its own strengths. But I would think a few upper-end Class A amplifiers beside Pass could somewhat portray what I am talking about. |
Tvad,
Understood on your correction comment about the single ended and balanced having MINIMAL differences. I was NOT trying to take your words and place them in a misconstrued context as it came across in my post. Apology extend.
Minimal Differences.. Minimal Differences.. |
It's also good to know the single ended connections are not any different then the balanced if I keep my CJ Act 2. Thanks Tvad..
Mozvz (Answers) Just to be clear for those who might not read every post in the thread, I did not state that the single ended connections are not any different than the balanced connections. What I said was that I noticed minimal difference (sonically) between them in my system. |
Mozvz, I responded earlier when you asked about the CJ ACT 2s synergy with the Pass. In a word, wonderful.
With the 100.5's on the Maggies now, I moved the 30.5 into my home office as an experiment. I've had the Cain and Cain Super Abbys in there for several years now and always got the best out of them with tube amps, especially SET's. The Abbys are a single driver/no crossover/fostex kind of speaker. Solid state made them sound hard and actually lose bass. Pass Labs and Mark at Renohifi both thought the 30.5 would pair nicely. I didn't think so. I was wrong. I'm listening to them now as I type. In three words: beautiful, relaxed and detailed. The XA30.5 is really a sweet amp.
Based on what you've said so far, I think you would be very happy with it. Onemug, Thank you for the updated information. I am still sifting through the choices with different scenarios in an equipment change/s. It's also good to know the single ended connections are not any different then the balanced if I keep my CJ Act 2. Thanks Tvad.. |
I've run balanced and single ended into my XA-60.5 from the same preamp, and I've noticed minimal difference. |
FWIW, Pass recommends balanced connections with their gear, c-j has never offered balanced connections. |
Mozvz, I responded earlier when you asked about the CJ ACT 2s synergy with the Pass. In a word, wonderful.
With the 100.5's on the Maggies now, I moved the 30.5 into my home office as an experiment. I've had the Cain and Cain Super Abbys in there for several years now and always got the best out of them with tube amps, especially SET's. The Abbys are a single driver/no crossover/fostex kind of speaker. Solid state made them sound hard and actually lose bass. Pass Labs and Mark at Renohifi both thought the 30.5 would pair nicely. I didn't think so. I was wrong. I'm listening to them now as I type. In three words: beautiful, relaxed and detailed. The XA30.5 is really a sweet amp.
Based on what you've said so far, I think you would be very happy with it.
Couple of technical points:
When switched on, it draws a little less than 200 watts from the wall. It does not heat up my office.
In standby, it draws just a few.
Standby generates no heat but keeps the caps charged so warm up is much faster.
Your CJ has a 12v trigger that can be wired to the Pass's trigger. Turning the CJ on turns the Pass on with no thumps or pops, always a concern with tube preamps.
Let us know what you decide. Good luck. |
the XA60.5 can certainly run enough full-size speakers, along with previously mentioned perks. As to the XA30.5, you must do your own homework, and especially don't just listen to anybody.
Spatine (Threads | Answers) I absolutely agree with Spatine. Fortunately, there are ways to hear the XA-30.5 in one's system before committing to the purchase, and if nothing else, the XA-30.5 provides the opportunity to hear how the XA-.5 line sounds. If you like the XA-30.5 at "normal" volumes (and it should do well enough on most speakers and in most rooms at normal volumes to give one a good sense of the XA-.5 sound), then you can decide to buy a more powerful version of the XA-.5 line if you want more volume and headroom. IMO, the XA-60.5 sounds essentially the same as the XA-30.5, and I would assume the same applies for the XA-100.5 |
It appears that a few people on this board are looking for non-commercial bias and honest opinion about how to choose a Pass amplifier. I would suggest that you review messages previously written about Pass XA.5 and X.5 series on this board, find ways to actually audition the amp. before consider buying, and call Pass Lab to get their advice on what amp to get given your existing stereo equipment. I did have to do my homework before buying anything. My few observations and some common sense are that: (1) People who are happy with XA30.5 tend to have smaller speakers; (2) Pass Lab personnel themselves when called upon are too proud to not give you what's right as opposed to what's profitable to them; (3) Class A amplifiers will heat up and will require some warming up time if you want good sound, but at least the XA60.5 of mine don't burn your hand like some other amp. would have; (4) All amp. regarding classification will go into clipping if you drive them that hard, but why would anybody want an amp. under-rated for the rest of their equipment? I can only tell you that the XA60.5 can certainly run enough full-size speakers, along with previously mentioned perks. As to the XA30.5, you must do your own homework, and especially don't just listen to anybody. |
Aldavis, it might be argued that class A amps might be more prone to clipping than class AB amps in that it's easier and less expensive to provide the neccessary power to avoid clipping with class AB than with class A operation. But, honestly, this is just an academic argument. |
Thanks for the clarification. I misunderstood. If by overdriving you mean clipping I would say that class a amps are not more prone to this. |
Aldavis, I'm not sure if your responding to my post or not. If so, I don't believe that I suggested that a Class A amp sliding into class AB would damage speakers. What I was suggesting is that over driving an amp could damage speakers. |
AFAIK there is no reason to think that any competently designed class a amp sliding into ab will damage speakers. The amount of class a delivered depends upon the bias current. Read Nelson Pass's paper on the subject on his web site. For high output solid state amps the inherent inefficiency of the design, however, requires huge power supplies, lots of heat production and large heavy heat sinks. Any manufacturer of a high output solid state " pure class a " amp which does not exhibit these characteristics is indeed exaggerating its capabilities. Reasons to choose ab over pure a include the desire for a small cool energy efficient amp or the need for very high output ( >500 watts) which is not very practical to achieve using class a. - Jim |
Despite the marketing hype, I believe it's not at all uncommon for some supposedly "pure class A" amps to drop into class AB at some point. Perhaps due to volume demands, perhaps due to impedance load, perhaps it can't draw enough power from the wall, perhaps it can't dissipate the heat and perhaps because the manufacturer is exagerating it's products capabilites. I think I would prefer an amp to slide into class AB rather than choke on class A and run out of steam or worse yet damage my speakers. This might partialy explain why some might choose a high powered Class A A/B amp with their particular speakers. |
Then, what's the class A/B rated wattage output above class A operation for the XA30.5?
I thought this amplifier was only class A. |
So long as the amp output is not exceeding the bias point (in Class A operation) the staff does not move.
Above bias point, the XA.5 amps will source something above rated wattage (they have about 4 dB headroom) and at that point the staff will swing right.
At that point the amp is still in Class A to the rated wattage, but above rated wattage it's A/B. This would be the classic A-A/B operation. |
I would imagine it would tend to exceed its rated power on peaks, which can happen often. Is it necessarily a bad thing that the meter moves, or is that to be expected with music dynamics and nothing to worry about if everything sound fine? |
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. |
Seems to me that Audiofeil might be in the position to offer the best advise on this one. |
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. |
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? |
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. |
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. |
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. |
My XA-60.5 get warm, but they do not get hot.
You couldn't make a melted cheese sandwich on them. |
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? |
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. |
Mozvz,
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.
RmRobinson,
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.
Peter |
Tvad,
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
Spatine,
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. |
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. |
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. |
Spatine,
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!! |
Mozvz,
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. |
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? |
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. |
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? |
Based on my experience I don't agree.
YMMV |
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? |
The amp will run out of horsepower IME. |
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. |
>>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. |
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. |
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. |
Mozvz, I believe the XA-30.5 would be a nice match for your speakers, your room, and your preamp. |
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.
Thanks,
Charles |
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. |
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. |
The Pass XA-30.5 is a terrific amp. Glad to know you're enjoying it, Rabbani. |
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. |
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 |
