What are the weak points of Pass amps and pre-amps ?
Though there are perhaps better transistor amps, but Pass seems to be an excellent choice for many. What is your experience with them, if you could elaborate ? Integrateds as well.
My experiences with pass labs gear has been very positive… well designed gear using quality parts , reliable and long lasting in terms of time and viability. I prefer the sound of the XA series amps for most music, leans to the right of neutral. the X series amps I find more neutral sounding and better for playing loud hard hitting music.. I am now using a Pass XP22 line stage after trying the XP12 for several months, my first foray into SS pre’s after decades of tubes and passives. I went from an XA25 to a SIT3 and enjoying low powered SET like sound. I like the First Watt amp sound the best so far, but proper matching and sensitive speakers is a must to get the most from it. Someday I would like to try the XA100.8 amps.. but right now this combo is quite enjoyable.. Price wise, I find Pass gear to be a good value, there are some amps out there that have $90k in the case work and $5K worth of parts and manufacturing. Pass is solid gear for the money. As with most things audio.. get what sound best to you..
I've bought and sold a number of amps over the years. Pass is one of the few I regretted selling in hindsight and the only one I reacquired, moving up from the INT-60 to the INT-250. I thought it might be overkill for my 100db efficiency speakers, but the data retrieval, dynamics, soundstage, bass grip, etc. is excellent in my system, my room and to my ears.
Pass are great amps in the right system or personal tastes. I jumped on the bandwagon several months ago and purchased a X150.8. My 1st impressions were, powerful, dynamic, very nice looking amp, clean crisp sound but lacked in midrange richness. I changed tubes in my preamp to help with some midrange energy I was experiencing even with Sonus Faber Olympica iii. It helped but overall I couldn't warm up to the amp. Hated to sell and wanted to like this amp but just couldn't get it to work in my system. YMMV. Overall it's a very good amp and compared to pricier products it's a no brainer. Extremely well built and affordable.
Earlier Nelson Pass Amps, particular Threshold used Bi-Polar output stages that had far higher current ability, which allowed them to drive lower impedance speakers without strain or current limiting like todays Pass Labs Mosfet output stage ones can. But Mosfets are more "bomb proof" than Bi-Polars, if the owner did something stupid and momentarily shorted the output or overloaded the input.
My only experience with Pass gear are the Aleph 3 and Aleph 2's I had many years ago. IMO, both were great sounding and when I decided to downsize I preferred the VTL MB125 just a bit more than the Aleph 2's I had at the same time.
The Aleph 3 I sold a bit prior.
I feel the Alephs get you real close to quality tubed gear territory without actual tubes in play.
The weak point is the cover. Tried standing on one and it caved right in. I was holding a Wilson Watt Puppy at the time. So that really was it after all.
I’m too considering Pass amplifiers. What strikes me the most when I read through all these lame responses to OP question, is the lack of almost all responses to include what speakers they used in their Evaluation of Pass amps. Amplifier speaker interaction is the most critical component matching region when putting together a system. 90% of the responses to this thread are useless IMO.
Gotta laugh at the people saying pass is not good or even bad or not engaging etc etc. Pass make incredible amps. I love my 350.8.
Oh btw @audiotroy is wrong. He said coda no8 does 150 watts class A. Uh no it doesn’t, its 150 watts ab into 8 ohms and only first 18 watts is class a. Please don’t spread misinformation and as an ’audio doctor’ atleast get the basics right.
We really are splitting hairs here. Yes there are some other real expensive brands that others might prefer over Pass but to these years Pass has always sounded very musical. They are made in the USA and the company support is second to none. No weaknesses that I can see or hear from Pass.
To OP. I have an xp12 pre feeding my xa30.8 into my tannoys. IMO tannoys and pass labs are a perfect match because Nelson Pass voices his amps using tannoys. This is the one time that I do not want more from my set up. The realism and ease to the music is second to none to my ears. The downsides (if any) are the xa30.8 takes awhile to sound its best.
I recently bought a Gryphon Antileon Signature to replace my Pass Labs X350.5. I will receive it next week. I have owned many Pass labs power amps and mono amps in 10 years of time.
This doesn't mean I will never buy a Pass again. Maybe I will buy later XS-300's. I loved all the different Pass amps I owned. And they made me really enjoy my music.
But sometimes you want to look a little further......
Hi Steve, where the heck are you where its still winter? It is Spring here in Michigan.....although a brisk 24 degrees tonight I think I will go turn on my amps!
Thanks for the information about the 260.8s. Keep the comments coming since those were sort of on my list to be interested in.
As a new owner of a pair of 260.8's and still in the 'new car' stage I can appreciate a number of the responces you have gotten. I moved from a ML333 which I liked very much to the Pass. As far as weak points, I have yet to hear anything that I would consider a weak point but again, I have had only one or two days of serious listening thus far. I do like the way vocals seem to be handled as to me, they seem to convey a in the room sound, very realistic .The bottom end is controlled and very responsive without being 'in your face'.
I have tried several genres and have, as yet, found anything they do wrong. I feel that is a good step up and I find myself enjoying music that I have not listened to for a while because I felt that the recording was not very good but details are far more layered with the Pass.
Yes, they tend to get warm, but as far as I am concerned after 8-10 hours no more than the ML. As there are now two I have noticed a slight increase in the room temperature (it is winter after all) I will have to see how they do this summer, but not terribly concerned, the sound out of them is worth any inconvience there
Like a lot of audio equipment, living here in Vermont, I haven't had a chance to hear a pass amp. But I think you can pretty much summarize from this threads lack of comments on their weak points, that most everyone is positive (very ?) about them. The class A heat being an obvious, to be expected, point. There were just a couple of outliers.
I have an Aleph 3 in storage now. It is sweet and delicate sounding but when I moved to a larger room it didn't work and maxed out below listening levels. It also runs warm and lacks bass punch and dynamics. It is transparent but speaks softly. I've never had high efficiency speakers but with the right speaker and a smaller room that amp could be magical.
My phono pre is an Aleph Ono that I've had for years. I find it very neutral sounding with good stage depth and imaging. It is also very quiet and has balanced outputs.
I've heard an XA200 and it was stunning. It had the same delicateness of my Aleph3 with way more dynamics.
In my observation, those whose hearing is good enough - no need for golden ear - hear very similarly but they can verbalize it in a different and sometimes unclear ways and of course, sound preferences differ. Most of people around me prefer electrostatic speakers, as an example, and I don't. As for the Pass gear, it doesn't appear to be for me, regardless of certain fine qualities that it has. I wouldn't consider Bryston or Sim Audio either. I would skip all that and go straight to Gryphon or some Swiss gear for transistor sound. No idea about Italian or German electronics.
I spent a weekend auditioning the X260.5 monoblocks and the glowing weak point in my set-up is their lack of speed and attack. Just sounded lazy when compared to Bryston cubed series monoblocks and Simaudio monoblocks. They were musical no doubt but sluggish.
I have a Pass X250.8 and it is wonderful in my system . I don't know where all this junk about heating a room comes from(I only wish). Yes they do run warm and you can feel some heat within a foot or so of the amp. Another great thing is the high bias class A, mine hardly ever leaves this mode.
We all hear differently. The Pass Preamplifiers and phonos are very neutral and what ever you have upstream, you will hear be it good or not so good. the thing is I do not want my Preamplifiers to sound like anything. Lots do unfortunately. The Jeff Rowland stuff is good but I certainly would not say it blows away the older Pass stuff. Synergy is the key in this hobby. The Pass, ,older or newer in the right system can sound fantastic.
Never owned the X or XA series amps or preamps, but have always felt the earlier Aleph series were somewhat overrated, having owned the Aleph 2/5 amps, P preamp, and Ono/X-Ono phonostages. The Ono/X-Ono, in particular, were so mediocre sounding compared to, say, a Jeff Rowland Cadence
I've only heard the 30.8 and the Int-60, but they were both outclassed by Perla Audio's Signature 50 integrated with Sopra 2's. All of them leaned toward the warm side of neutral which I like w/ the Sopra's, but you could easily tell the Perla Audio integrated had superior clarity and image specificity without sacrificing density and that relaxed liquid sound that the .8 series has. The Perla amp also uses only 5w in standby mode and never even gets warm, let alone Class A type of hot.
I also preferred an AVM integrated (not sure the model, roughly $10k range) to the comparative Pass offerings as well.
Never buy anything from a human that is trying to sell you something. They are way too dangerous. Chord? Are you kidding me? The difference between Pass and Curl designs is that they actually care what their amps sound like and they actually know how to listen to them on top of knowing what their customers want. Frankly, if it is art you are looking for buy a Boulder, best low distortion art out there . Oh, and if anybody thinks they have to spend that much money to get incredible sound they are out of their mind!! Besides, it is a lot more fun doing it on a budget.
High efficiency or perhaps more correctly high sensitivity unto itself is an admirable attribute. High sensitivity can play louder, tends to allow lower amplifier distortion, reduce power requirements and ergo reduce cost,size, weight and heat. High sensitivity also allows more noise into the signal. On the other hand it’s easer to create a steady lower impedance than higher one. A steady impedance is easier on amplifiers, reduces the potential for phase angle challenges, and frequency response linearity deviations. There are many considerations that go into speaker design, balancing them all sometimes requires sacrificing the ultimate capabilities of some attributes in order to better accommodate other considerations. How many commercially available high efficiency loudspeakers capable of time and phase coherence can you name? How many high efficiency speakers can demonstrate a good step response or square wave?
One obvious advantage of high efficiency and easy to drive (i.e., uniform impedance) speakers is the ability to drive them with less powerful amplification and having a greater choice of amplification for the money. I wish I had considered that years ago but instead now have myself in a position where I need rather large (and therefore expensive) amplifiers. The cost of high quality amplification per watt of power goes through the roof when you need a lot of watts, and you can forget tubes unless you want to spend a fortune on tube replacement.
It would have been nice to be able to use something like the First Watt amps, the lower wattage 30 wpc Pass Class A amps, or any number of under 50 wpc tubed or SS amps available.
Hi kosst, I think that opens up a whole can of worms of whether a low or high efficiency speaker inherently sounds the best? One would think that if all high efficiency speakers sound better than their low efficiency counterparts there would be no need for higher powered amps as there would be no speakers needing that power.
Now going off thread, I guess the question is what are the advantageous and disadvantageous of low and high efficiency speakers?
pwhinson, when you previously wrote that Pass recommended the X series over the XA series I wondered if they mentioned to you why they made that recommendation? I am sorry to say that I have never heard a Pass, but it would seem that either series has high wattage amps that will drive most speakers, and that which you purchase is a matter of whether or not you prefer a class A sound and a matter of costs?
@inna, I don't think the X series or the XA series is "better" than the other absent the type of speaker you're trying to drive. FYI I was all ready to purchase the XA series monos and Kent at Pass told me that the X series was better suited to my speakers, Thiel 2.4s. The ONLY possible fault I can come up with is that there ARE solid state amps that provide bass that is tuned tighter than the Pass products although I think the X series is a little better than the XA series in that regard. Its all speaker dependent.
The Ypsilon preamp and phono preamp were driving Viva tube amps which were driving Avantgarde Trios and 3X Basshorns. Yuk! Switching out cabling from High Fidelity to GroverHuffman cabling made it listenable but still rather thin, bright and forward. Substituting Viva preamp and a custom designed tube pre-amp, wow, the sound mellowed and became enjoyable. We suspect that the phono preamp is also on the bright and forward side using a Kiseki on a Caliburn/Cobra setup. We also tried CDs. I know, Michael Fremer owns and believes the Ypsilon to be his favorite. Maybe in his system but not in the one I heard.
Yes, jetter, by all accounts for the price it is an excellent choice if you don't need more power and current. Besides various acoustic and vocal music, I listen to jazz rock, and with my current and I believe future speakers I would need more than what the Pass can deliver. That's in addition to what I said earlier.
jetter, I am almost certain that Pass would not be good enough for me, definitely not when high - for me - cost is involved. I would have to wait longer and go higher. Pass seems to be a solid choice, that's all. As for the Ypsilon experience, there was something terribly wrong either in that system or with the listeners or both. Some do say that Ypsilon may sound a little bright and forward, but it depends on the rest of the components and preferred sound. Stage III cables are often used with Ypsilon.
I had a 350.8 so I'll address the heat issue. I found it surprisingly warm to the touch. But it did not heat the room. I would have loved to have kept it but it was just too large for my small apartment. As it is so small I am very sensitive to heat and stuffiness issues. The temperature of the Pass in no way affected the atmosphere in my room. Others may have a different experience but this was mine. Had it not taken up so much real estate(you really don't know do you unless you have it in your personal space)I would not have parted with it.
In my opinion, talking about amplifiers without mentioning the rest of the system, e.g., preamp, speakers, etc., is pointless. Most of the “engaging “ aspects of the sound quality comes from the amplifier pairing with the speakers., and in the right room. I’ve heard several moderately priced “systems” that were a lot more engaging than systems costing multiple times more.
I have extensive listening to a high end Ypsilon preamp a new friend's home. That and High Fidelity cables had me run from his listening room the first time. After replacing the horrible cables, the preamp was the next culprit of an $850,000 system in producing bad sound. It was replaced by a VIva pre-amp. I doubt Pass pre-amps could sound as bad as an Ypsilon.
Hi inna, I have been considering purchasing a pass amp, so I have been following this thread. You inquired regarding the weak points of pass amps, and just guessing you received about 99 responses praising their sound, and two or three not positive responses. I thought the responses were overwhelming favorable, do you mind mentioning what lead you to think otherwise? Thanks
Alright, I think I get the picture. bsimpson, I especially thank you. You confirmed my impression that was formed after reading all the posts and a few other threads and reviews. Sound, whatever else it should be, must be engaging. Just like people, I could add. So, practically speaking, it appears that I have no need for Pass. From what I gather, brands like Gryphon and Ypsilon are not just better, not in another league, but in another universe. And that is worth paying for.
None of the Pass products (including the classic Nelson Pass stuff) are engaging IMHO....
... from sound perspective
... and from my bullying friend's perspective (he keep bragging and preaching about his Pass)
Don't get me wrong. They are fine products by any standard. But just don't engage me at any level. Almost like Boulder. I feel like I am listening to an top notch electronic lab instrument.
Wow, I didn't think that an amp was so sensitive to ambient temperature and vibration/movement that it would affect bias (for a solid state amp yet)! I don't like touching the insides of an s.s. amp to adjust the trim pots with meters while on. Yuk!
88*F=31C which is probably too cool.
Nelson has posted elsewhere for older X series amps that 45-55C on the heat sinks is reasonable (along with what that subjectively feels like by hand in case you doubt the thermometer), and the manual for your 350.8 specs a temp of 53C (127F), so Pass recommendations seem historically consistent. Your amp could probably stand to have the bias increased a tad. At least on my old X150, the trimmer pots are so fricken sensitive that lifting the amp, carrying it across the room and gently setting it down will mess up the bias and offsets, so I readjust after I've moved the amp to where I want it. I shoot for 48C in winter time, so given the ambient temp changes in my man cave it will run about 50C in summer.
A few say that Pass amps are better than preamps, not that preamps are no good. I heard the same about Rowland, Lamm and others. It appears that it is more difficult to make a great preamp than power amp. Who is going to make great preamps ? Let me guess - just a handful of tube guys, correct ?
The weakness of Pass (I live in France) :- not unexpensive- of course there are better one at much higher price- hard to find used- "
It will become clear that they lack realism in the individual focus of
voices and instruments. When you listen to voices and instruments in
real they are very small and direct. The Pass Labs preamp and power amp
are not able to create the intimate focus as in real."I completely disagree after having played piano for over 35 years and along with a musician who has recorded as a soloist backed the Concertgebouw the Beethoven Violin concerto. We could listen both to the rehearsal (hall empty) and to the concert (sold out). This is the point of other musicians - User manual could be clearer- No Trade in available in France (they should had this point on their binding contracts with their distributors added) so upgrade is almost unaffordable.- IMHO, their amps are better than their pre Pros :- keep on upgrading, trying new ideas and finding new solutions- can reach them and have you're questions answers quickly - Pretty much on the melomane (music lover) side - faithfulness - rather than on the audiophile (sound lover) -more pleasure even if it implies distortion -.Some are melomane, some are audiophile, both points of view are equally respectable. I'm a melomane. IMHO, they are not designed to please everybody but to
WYHIWIOTS (What You Hear Is What Is On The Support)
. So it's more a matter of love or dislike. I love them.
Note, one could fry an egg on a hot EAR 890 amp, it’s that hot for the chassis and transformers, dangerous to touch after 1/2 hour. Pass amps currently list their temperature at 127 degrees, above warm and slightly hot.
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