Are Nelson Pass's Greater Accomplishment his High-Powered Designs or the Lower-Powered First Watts?

caesar

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Seems like the hard-to-drive speakers are marketed better these days, so I am sure he sells more of the X and XA series. But whereas his XA series is frequently criticized for sounding mushy and having tubby bass, people seem to really love his lower powered stuff.

Any thoughts?
 

JackD201

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I've heard his FW amps on horns and was impressed. He's come a long way from his Aleph 0s which I owned. The Zeroes were warm but had a grainy lower treble evident even on soft domes. Not so with his later stuff.
 

PeterA

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Seems like the hard-to-drive speakers are marketed better these days, so I am sure he sells more of the X and XA series. But whereas his XA series is frequently criticized for sounding mushy and having tubby bass, people seem to really love his lower powered stuff.

Any thoughts?

People also seem to love his higher powered stuff. If the XA series sounds mushy with a tubby bass, my guess is that it is not paired with the right speakers in the right room. I started with the Aleph 3, then Aleph 5, then Aleph 2, then XA160 to XA100.5. Each had more power and better control, and each sounded better on the same pair of Eggleston Rosa speakers. Then I went from the XA100.5 to XA160.5 on my Mini IIs. Again the more powerful amp was an improvement on the same speakers.

I think all of NP's current designs can sound great under the right conditions. I read that he derives the most enjoyment from playing around with different amplifier sounds. He seems fascinated by listening to the effect of different circuits in different conditions. His joy comes from tinkering and discovering and listening. I do not know if he personally prefers some designs over others, but I did read a response to a similar question once. He said, paraphrasing, "How can one choose between his many children? I love them all." He designs specific amps for specific contexts. He may well be the most prolific amp designer alive.

If I had efficient, easy to drive speakers, I would consider his FirstWatt designs, particularly the SIT monos.
 

caesar

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People also seem to love his higher powered stuff. If the XA series sounds mushy with a tubby bass, my guess is that it is not paired with the right speakers in the right room. I started with the Aleph 3, then Aleph 5, then Aleph 2, then XA160 to XA100.5. Each had more power and better control, and each sounded better on the same pair of Eggleston Rosa speakers. Then I went from the XA100.5 to XA160.5 on my Mini IIs. Again the more powerful amp was an improvement on the same speakers.

I think all of NP's current designs can sound great under the right conditions. I read that he derives the most enjoyment from playing around with different amplifier sounds. He seems fascinated by listening to the effect of different circuits in different conditions. His joy comes from tinkering and discovering and listening. I do not know if he personally prefers some designs over others, but I did read a response to a similar question once. He said, paraphrasing, "How can one choose between his many children? I love them all." He designs specific amps for specific contexts. He may well be the most prolific amp designer alive.

If I had efficient, easy to drive speakers, I would consider his FirstWatt designs, particularly the SIT monos.

Hi Peter,

With all of the filthy, disgusting, despicable, and worthless reviewers out there, that lick the manufacturers' xxx so they can get the next model in for review for a good number of months, while screwing over hard-working audio fans, getting them to waste time and money, a man of highest integrity like John Atkinson, a true rarity in this hobby, even admitted that the weakness of xa is mushiness and tubby bass.

I think Pass is trying to copy "typical" tube amps with that product line: the good, the bad, and the ugly.
 

PeterA

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Hi Peter,

With all of the filthy, disgusting, despicable, and worthless reviewers out there, that lick the manufacturers' xxx so they can get the next model in for review for a good number of months, while screwing over hard-working audio fans, getting them to waste time and money, a man of highest integrity like John Atkinson, a true rarity in this hobby, even admitted that the weakness of xa is mushiness and tubby bass.

I think Pass is trying to copy "typical" tube amps with that product line: the good, the bad, and the ugly.

You asked for opinions and I gave you mine. It seems our opinions differ. That is fine. Pass also has the X line. They sound different. As I wrote earlier Nelson pass seems to enjoy designing very different sounding products which are meant for different customers and different situations. People can choose one of the designs or buy amplifier from a different company. It is a big market place out there and I think they sell a lot of amplifiers.

Are you interested in discussing high powered versus low powered or are you interested in discussing the sonic characteristics of the XA line?
 

caesar

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Peter, completely agree that it is silly to argue about tastes. But it may also be a scenario of being experientially impoverished. I wonder if people who like XA and can accommodate tubes in their setup, would be happier with CAT...
 

caesar

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And I guess I am arguing that XA series may not be Pass's greatest accomplishment, despite satisfying a market niche...
 

PeterA

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Peter, completely agree that it is silly to argue about tastes. But it may also be a scenario of being experientially impoverished. I wonder if people who like XA and can accommodate tubes in their setup, would be happier with CAT...

I don't know the answer to that question, caesar. I am one of those experientially impoverished audiophiles and have been criticized by some for being too brand loyal. However, I have heard two Pass amps (XA 160.8 and XS 150) and the large CAT JL7? monos in the same system, though at different times. In my opinion, large CAT monos are not as dynamic or have the same control over the lower frequencies as do the Pass amps. Based on that impoverished experience with this extremely transparent and resolving system, I would not be happier with the CAT in my own system. But I have just one opinion and it is based on my subjective taste.

Are you now interested in going off your original post topic and making this discussion about the Pass XA amps versus the CAT amps? I thought it was about NP's greatest achievement. What does CAT have to do with that?
 

KeithR

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And I guess I am arguing that XA series may not be Pass's greatest accomplishment, despite satisfying a market niche...

Not sure why you think this - even JA said the 60.8s were the best amps he's ever heard.

Clearly matching Class A amps to the appropriate speaker is more challenging vs. Class A/B.
 

cjfrbw

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I'm hoping that Nelson Pass will lend one of his new SIT3 First Watt amps to the Zu guys for the next California Audio Show, and will also have another Pass XA25 out there somewhere, too.

I thought the XA 30.8 sounded pretty good last year, certainly at that time better than the big brothers all over the show. The XA25 also sounded very good on a more modest system. I have never been able to filter the steely thumbprint out of the larger PASS amps. The Pass XA25 might be the best sounding production PASS ever, being a First Watt concept amp committed to the more rigorous Pass fascia with an additional gain stage. It uses a single pair of hockey puck MOSFETs per channel with very high specs, and goes to 100 watts at 2 ohms.

I would give my EI vote (Experientially Impoverished) to the SIT amps, the unobtanium VFET Pass monster, and my knock off Pass designed DIY VFET as being amongst the best amps ever, even compared to my beloved tubes. They can't really be compared to tubes OR solid state, they are on their own playing field.
However, only the VFET monster would glaze the eyes of the big steel, outlet roasting, forklift loving flash 'n edifice audiophiles.
 

PeterA

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Great post, cjfrbw. It looks like you think the better Pass amps are the lower watt designs. I think that Nelson Pass does like more efficient speaker designs.

I have heard and read great things about the XA25 and 30.8 but never heard them. You make an interesting comment about the "steely thumbprint" of the larger PASS amps. My good friend Madfloyd observed what he called a slight "metallic" sound from his larger Pass amps and/or preamp. I asked him if he ever heard that same same attribute in my system with my large Pass amps and he said "no". I can only surmise that it is system dependent, but then again, I never heard it in Madfloyd's system, so who knows?

I agree with your characterization that Pass amps sound neither like tubes or solid state. I think for the most part they combine the better attributes of each typology.
 

Al M.

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You make an interesting comment about the "steely thumbprint" of the larger PASS amps. My good friend Madfloyd observed what he called a slight "metallic" sound from his larger Pass amps and/or preamp. I asked him if he ever heard that same same attribute in my system with my large Pass amps and he said "no". I can only surmise that it is system dependent, but then again, I never heard it in Madfloyd's system, so who knows?

Yes, I've heard it too in Madfloyd's system, and never in yours.
 

PeterA

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Yes, I've heard it too in Madfloyd's system, and never in yours.

Al, you should try to listen the my 30 watt single ended Class A Aleph 3 amp that I lent you. It's an old design and my not have the dynamics you require, but I remember it being a very sweet sounding amp. It would be fun to hear it in your system and see if it holds up to new designs.
 

Al M.

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Al, you should try to listen the my 30 watt single ended Class A Aleph 3 amp that I lent you. It's an old design and my not have the dynamics you require, but I remember it being a very sweet sounding amp. It would be fun to hear it in your system and see if it holds up to new designs.

Yes, I had planned to do that at the latest when reviewing my Octave amp, as a reference, and possibly earlier. It sure is a fun and exciting hobby! And thanks again for lending it to me, Peter.
 

bazelio

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I have the impression that Pass designs different solutions for different niche markets. He even writes about this.

I believe niche is First Watt, with Pass Labs intending to have mass market appeal.

On the original topic, I just brought in a loaner/demo XA30.8. It still needs to break in according to Reno Hifi, and should be ready for real critical listening by Sunday. Early impression: I would agree that the XA30.8 could be characterized as having somewhat tubby bass. But it's going to depend on your reference. It's better in terms of being tighter than .5 series bass, and it's certainly not stereotypical farty tube amp bass. :p As far as low power vs high power, there are going to be two camps. The XA30.8 is said to appeal more to SET crowds as a result of its big tone, but then as you go up in power, the bass control (and other technicalities) are said to improve. Many folks prefer the overall sound of the lower power models for their preferences and vice versa.

Time will tell if I keep the XA30.8. I should have some good listening time this weekend.
 
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cjfrbw

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I also own the First Watt M2, which I bought several years ago at a very steep discount as a backup amp. I would plug it in once in a while, thought that it had good things about the sound but also a bit wonky and gamey for some reason.

M2 is basically a voltage gain auto former with a single pair of MOSFET per channel and no feedback anywhere.

I almost sold it but decided to give it a full court audition instead of the occasional 'toss it in and listen to it cold' routine. I left it on for a week, and boy, it really woke up. I don’t know why maybe it is the open loop design, but it might just need a lot of break in and galvanic and temperature stability to open up, but open up it did. I’m glad I kept it and now use it for the time being as a STAX headphone amp in Santa Cruz, where over many months it continues to improve with use.

M2 is a hard amp to describe. It seems to be one of the favorites of the DIY crowd amongst the First Watt designs released to them, with some of the SET/Horn crowd adopting it in lieu of their toobs.

Where the M2 and the VFET part company, they are already at a very high standard of detail, sound stage and imaging. VFET veers off towards absolute separation and black spaces with deepest tone retrieval. M2 goes toward a kind of whole-ism and organic connection to the sound tapestry, with great PRAT (if you find any meaning in that acronym). M2 does a strange thing on speakers. When sound, especially grouped sound, gathers up and moves louder, the whole sound stage seems to light up to give a vivid image of the performance and venue that kind of flashes off into space. Upper mids have lovely gloss and sheen. M2 has perhaps the best rendition of live strings and massed strings I have heard in my system, not at all solid state and very convincing.

It seems the new SIT3 is an effort by Pass to harness a bit of each of the SIT/VFET trait and the M2 trait, because it also uses an auto former voltage gain stage with a very unusual push pull output consisting of a SIT and MOSFET in tandem, very carefully chosen to match characteristics.

If the SIT3 can succeed at merging the qualities of SIT and M2, it must sound like quite something. That’s why I am curious to hear SIT3.
 

PeterA

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I believe niche is First Watt, with Pass Labs intending to have mass market appeal.

On the original topic, I just brought in a loaner/demo XA30.8. It still needs to break in according to Reno Hifi, and should be ready for real critical listening by Sunday. Early impression: I would agree that the XA30.8 could be characterized as having somewhat tubby bass. But it's going to depend on your reference. It's better in terms of being tighter than .5 series bass, and it's certainly not stereotypical farty tube amp bass. :p As far as low power vs high power, there are going to be two camps. The XA30.8 is said to appeal more to SET crowds as a result of its big tone, but then as you go up in power, the bass control (and other technicalities) are said to improve. Many folks prefer the overall sound of the lower power models for their preferences and vice versa.

Time will tell if I keep the XA30.8. I should have some good listening time this weekend.

Let us know what you think of the 30.8.

I think all markets in high end audio are niche. What I should have written is that Pass has the X line and the XA line which appeal to different tastes and may work differently with speaker demands. For a while, they were also selling both the .5 and the .8 series. If you include the integrated amps, and the XS line plus the First Watt stuff, that is a lot of product, not including all of the preamps and phonos. I don't happen to think that Pass Labs products appeal to the mass market. They are just too expensive. I do think that the production runs for the First Watt amps are much smaller than are the runs for the main Pass products, except for possibly the XS line.
 

rockitman

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I agree with your characterization that Pass amps sound neither like tubes or solid state. I think for the most part they combine the better attributes of each typology.

The XS series is his greatest accomplishment and I agree completely with your best of both worlds assessment...
 

PeterA

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The XS series is his greatest accomplishment and I agree completely with your best of both worlds assessment...

Christian, Not only that, but I heard another clear attribute with the XS series. I once compared the XA160.5, XA160.8 and XS150 in a very revealing and transparent system. They all sounded different. The .5 portrayed the sustain and decay of the note beautifully. The .8 did a better job with the transient or attack of the note, but had a truncated decay and underdeveloped sustain of the note. The XS combined the best of both amps and presented the whole note, from attack to decay in a very complete and natural way. I was really impressed with the XS amps. I agree that for the large amp designs, the XS is his greatest achievement. I have not heard the latest small amps or the First Watt amps, so I do not know how they compare to the XS.
 

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