Pass Then vs. Pass Now

I don’t have your speakers but I did have Adcom 555 and 5802 with B&Ws and Dynaudios and Martin Logans. While I enjoyed these amplifiers, my Pass Labs XA30.8 is in a completely different league.

Oh and I also had Rogue RP-1 and RP-5 with Rogue ST100 amp. The XA-30.8 is what I moved up to. 

Grab that Threshold 400A before someone else! It is a superb amp! I’ll take it any day over a new Pass! I’d also sell the Rogue and get a Threshold preamp to match the 400A. Since you like tube preamps I can recommend a Precision Fidelity C2 from the late ’70s. A superb tube preamp designed by Bruce Moore (of the later MFA - Moore, Frankland, Associates fame).

Threshold Is without a doubt a good amp. Problem with vintage amps is if you need parts replaced. Those oil can capacitors, other parts. Are these amps even supported today? Shipping that amp for a repair will cost a few bucks as well.
This alone can bridge the price gap. This is all not factoring into the equation that the new XA design takes advantage of modern technology, years of lessons learned and readily available parts and awesome Pass customer service. 

Thanks! I am leaning towards the XA30.8 for many of the reasons stated here. I think I needed to hear someone say that it is in another league above the Rogue sound that I have been listening to (and enjoying - that Sphinx punches way above its class). 

While I love the idea of vintage gear, I am also not that technically inclined myself so I would have to pay for maintenance and deal with the headache. I live in NYC so there are enough local resources to do the job but they are awfully pricey.  Reliability is why I am sticking to solid state in the first place.

That said, the Threshhold sounds like a bargain at the price and one for which there will always be a market if it doesn't work out... 

Seek out a Pass XP-12 preamp in the future if you land the XA30.8. Keeping the synergy between components is very important. 

I have owned Pass since the Threshold s500, then x350 up until fairly recently. I can say unhesitatingly, contemporary Pass amps are tremendously better than the ancient Threshold. The character of the Threshold or his newer xSeries are similar… emphasizing power over finesse. XA is more about finesse over massive power.

So, given what you have, your interests and where you are, I would definitely recommend an XA30.x. This will be in line with a more musical fleshed out tone. Sounds like a good match for you.

Another vote for getting the XA30.8. Using the Sphinx as a preamp is doable, but won’t you be running the output section as well? I’m pretty sure it will be okay being as it’s a class d output, but I’d check with Rouge Audio and make sure you won’t muck up something by running it without a load ( speakers ).

Anyway, if you like it, great, you have a system you like and if not, you should be able to sell the V3 and get a different preamp.

All the best.

My FirstWatt F8 is terrific, driven by a tube preamp. Your Devore Gibbon 3xl speakers have a high enough sensitivity that the F8 can drive them just fine.

May theschwartz be with you….

op

don't rule out the xa25 either, it is excellent, plenty of power for your gibbons

kind of a lovely mid ground between x and xa series sound...

I’ve owned a lot of amps over the decades (including a couple of 535s, preamps, etc.) and still use a later Adcom amp in my video rig. I had a great sounding Forte Model 55 amp that was sort of "Threshold adjacent" just before going all tube...in any case, I now use a Pass XA-25 and it’s frankly an astonishing sounding original design from old Nelson. Design wise it’s nothing like any other Pass amp (perhaps somewhat closer to his First Watt clever stuff) other than being a seemingly bullet proof beautifully made thing...and a relative bargain built to last for years.

@wturkey  you realize there are two sides to every schwartz ....

I have slightly more sensitive speakers and when I went looking for my Pass amp, I was between the XA30 and the XA25. Those who had tried both said there was something especially magical about the XA25. (Of course there's always a debate!) I was concerned about the power level but in all honesty, the XA25 is NOT a 25 watt amp and has plenty of power given the very nice ohm-load your speaker presents. Harley Lovegrove of Pearl Acoustics agrees, here.

Then there's this 6moons review that quotes Terry London: "Wanted to share that I just got through submitting my writeup on the Pass Labs XA25. I believe that this might be the best amplifier Nelson and his crew have yet created/built. I own a pair of XA-60.8, a FirstWatt SIT 2 and have had in my system an XA30.8. The XA25 does color, tonality, spatial qualities, bass control and overall macrodynamics different and better for my taste than these other wonderful amplifiers. I still cannot believe that I'm not listening to a great tube SET were it not for how quiet, quick and dynamic the XA25 presents the music."

Your speakers sound easy enough to drive for the XA 25 -- as Stereophile put it, " Its sensitivity is specified as 90dB/2.83V/m—rather high for a small monitor speaker. The impedance is given as 8 ohms—a "very flat" 8 ohms, according to John, and never dropping below 7.4 ohms."

Threshold made fabulous gear, but a 400A would be >40 years old now.  If it hasn't been updated, you should definitely include the cost of having it gone through, and at the very least having the power supply & other electrolytic caps replaced.

It will still be less expensive than a Pass or First Watt amp, but you get great sound at a discount.  If you have the budget, Pass is still going to be your safest bet, though. 

Nelson has always been clear that he knows we all have different sound priorities.  He started FW as a venue to experiment with different output devices, and optimize their unique sound signatures.  That's why FW doesn't have the traditional pricing hierarchy found at most amp makers.  While a fascinating concept, it puts more of an onus on the buyer to choose their own favorite "sound".

Coda S5.5 could be strong alternative in class A contenders. Threshold is gone, and while Nelson Pass, founder of Threshold, has been producing amplifiers under his own name for some years now, other former Threshold employees are also designing and manufacturing power amps. Their company is Coda Technologies, and their amplifiers are completely up to date in terms of parts quality and circuit design. 

XA 25 is a very pleasant sound with good bass control. Xa30.8 is double the weight of the XA25! It’s very rare to hear someone say they they don’t like the sound. Tastes do vary.

I think the first watt stuff will lack reserve power.  If you don't listen very loud probably OK with excellent sound.

I saw a completely rebuilt Threshold a while back.  $2500.  Demo pass units will start around 4000.

i have had the xa25 along with an int150 (x150.5 with pre front end) and also xa30.5 - have bought the xa25, sold it, bought it back, sold it again through speaker evolutions...

all three are truly excellent but of course, they sound different, do different things well

xa30.5 sweetest of the three in the treble and upper mids, most tube like, if you will -- with excellent tonal density and very good bass control, and ever so slightly softened transients

xa25 is less sweet, more ’straight wire with gain’ in the treble, but still tonally dense, and slightly better bass control, sounds faster more like an x series, than xa

int150/x150.5 similar to the xa25 in treble extension, tonally a bit less dense/saturated, tremendous bass impact and control, mids slightly leaner (just slightly), and of course, a notch greater headroom

i think the differences above capture the essence between the xa25 (which i consider a middle ground between x and xa amps for reasons enumerated above), and what would be consider typical xa vs x series amp’s sound

basis for my commentary is driving the following -- spendor sp100 r2, harbeth mon 40.3/40.2, magnepan 1.7i/3.7i and most recently, laufer technik notes

@jjss49 

Which of the Pass amps you tried could handle the Maggie 3.7’s?

@swede58

in my 17x20 room, maggies 4+ ft into the room, 10-11 ft listening triangle, all three amps drove the 3.7i’s just fine, never felt strained

but i don’t listen at headbanging levels, mid 80 db transients

know that the xa25 and xa30.5 have been tested to deliver 130 wpc and 190 wpc into 4 ohms respectively without clipping... the maggies are a purely resistive 4 ohm load, as such they draw current, but phase angles are completely benign, no stress on the amp in that respect unlike cone/box speakers with reactive phase angles and severe box resonances amps must often contend with

@jjss49 

Thanks, I’m hesitating between a Pass XP22/X260.8 or X350.8 combo or the Gryphon Diablo 300.

So many years ago, I bought a Threshold power amp, and it was an 'S' series, maybe 400 model? The point that I will make here is that even back then, I was surprised to see how ancient it looked with old brown carbon resistors, thin circuit boards, and more. To me it really looked used. I mention this because in some newer equipment, I see thick circuit boards metal film resistors and the electrolytic capacitors have come a ways since the cave days. No doubt there is equipment built in the past that was great then and now, but I didn't find that to be the case in the Threshold amp that I had.

 I wish that I could speak to the more recent products designed by Mr. Pass, but the only power amp of his design that I owned and loved was a Forte' model 3 which quite the opposite inside from the Threshold. Then again it quite a few years newer so there is that. 

 The Pass products that I have seen recently have good quality in places (I am now referring to some of his kits) but not so much when it comes to the chassis. Not bad at all, but certainly not built like a Krell either. His consumer products I have not seen to get even an idea of the build quality.

 I am not saying that any one of these products sound good or bad, but I am just as interested in the build quality as the sound. I know, a rare combination.

@4krowme you had me at the Pass kit to Krell comparison. 
 

 I am not saying that any one of these products sound good or bad, but I am just as interested in the build quality as the sound. I know, a rare combination.

You clearly have internet because you posted here…so Google is your friend…or whatever search engine you prefer. 

Wow. You are right... about the chassis. I will just keep googling until someone shows the guts inside. I've seen some pretty sorrowful crap inside a beautiful chassis, but I am betting that Nelson does way better than that. 

audphile1,

 Excellent response, thank you. Nothing is perfect, and in spite of the intent, the camera moves around too much to get a really focused look at certain things. I know, I am being picky. 

 Like I said earlier, the chassis is really impressive (especially the binding posts attached to the chassis!). I would want to build like this if I had the money. Making of such a chassis out of sight. Internally, it is interesting to see that it does remind me in some ways of my Forte' 3. Now this is a personal thing, but I never really did accept the use of ribbon cables, even though much of the idea is spot on. It is not the cable so much as the connectors. Unless they have a really good grip, intermittent problems can arise. Again, a thing with me but there are several Bourns pots in terms of quality that are available, and they are identical just looking at them. It was one of the problems in my Forte' before I rebuilt it. 

 So, since I have never owned an actual Pass Labs product (yet I have built a few of their kits), I cannot speak to the sound at all. My personal experience is that the Threshold power amp that I owned wasn't my thing, the next three Forte' products that I owned were absolutely great, and if I could, I would very much like to hear what these products actually sound like. They do have a great following. 

 Again, I do appreciate the video. 

@4krowme Hey not trying to prove anything here. Just found your comparison and comments odd and baseless. And they still are. Have a nice day. 

@swede58 

Thanks, I’m hesitating between a Pass XP22/X260.8 or X350.8 combo or the Gryphon Diablo 300.

i don't know the size of your room, how loud you want to play your maggies

those are very powerful options you are considering... for my application they are clearly overkill

i also prefer the slightly better (to me) tone, delicacy and saturation of pass' class a amps - of course, very high power xa versions of those are also made... but they are expensive, generate a lot of heat, use alot of power...

The 400a was a nice amp in its day.  I owned one for several years.  The newer Pass stuff (I've owned several) sounds much better.  Unless the 400 has been rebuilt, expect problems.  Mine was in the shop more often than not before I finally sold it.  Unless you live close to someone who will repair it, I'd stay away. Your wallet and back will appreciate it. 

When Nelson Pass started Pass Labs, and left Threshold, his first amps were the Aleph Series of amps.  In my wanderings, I've had the good fortune to own a Aleph 5 (60 wpc Class A), then Aleph 2 monoblocks (100 wpc Class A), then finally the keepers, Aleph 1.2 monoblocks (200 sweet wpc Class A); these Aleph 1.2s are real room heaters.  Back in the day, I tried a series of Stereophile Class A preamps and they sound from okay to meh.  From what I remember, I had a Adcom GFP 750, a Sonic Frontiers Line 2 with outboard power supply; I even rolled different 6922 tubes looking for that thing that I was hoping to find.  Finally, I had enough scratch to buy Nelson Pass's new series of "X" preamps, which was the 3 box X0.2.  OH MY!  The total synergy of the X preamp with the Aleph 1.2 was something to behold.  That beautiful midrange bloom that everyone talks about from the Aleph series of amps came out to play; that lit from within detail where the inside and shape of wooden instruments could be heard.  The transient of a harp string or guitar prick - the onset of the note proper, followed by the trailing note.  Depth, width, hearing individual instruments in a 3D space.  It was all there.  This equipment was mated up to Von Schweikert VR-6 speakers, which are very fast.  The Aleph amps tamed that beast, and the detail from that Focal tweeter and front firing two 4 inch mids just all fell in synch. 

I then moved and started second system with Pass gear.  The pre is the 3 box XP-30; amps were X60.5s and my speakers with Focal Mezzo Utopias, which is all a splendid grouping.  This newer equipment smokes my very musical Aleph for detail, transient snap, greater 3D picture of instruments in a field, greater height, and that individual sound and the very specific dimensional shape of a note as it bounces in a venue when it is picked up by sound engineer's microphones is borne out.  Again, that midrange bloom, and lit from within sound that somewhat honey coats the music is very enticing to my ears.  Now, that is not everyone's taste; I like gear that errs on the side of warmth.  Presentation that is threadbare in the midrange or has that laid back presentation, ehh, while not to my liking, it is not the end of the world.  New Pass has that greater overall detail, more punch, better flow, better transient snap, and also much better bass than the old Aleph amps.  Sorry for the verbose passage here.  If you get Pass amp in the X30.8 (which is a fine sounding amp), be sure to listen to it connected to a Pass XP-12/XP-22/XP-32 preamp so you will hear the magic and synergy of a Pass pre and amp playing together; you MUST do this. 

>>>gfys now??? You should run for office.

   My observations are based on actually owning multiple products designed by Pass. Most of them I liked, but also most of them could have had better build quality inside.  

  I have seen people like you too. Easily offended by any other perspective. So then the first response is a passive aggressive comment, followed by a vulgar shoot from the hip type remark. 

I don't have experience of the Gibbon but have experience of the O96 with Passlabs amps. The .8 series are superb power amps. As per a previous poster, I would certainly look at selling the Rogue in favour of an XP12 pre. That is a very nice sounding pre / power amplifier combination to drive highish sensitivity speakers.

 There is something to be said of Nelson Pass as a person. He reminds me of the Grateful Dead, who allowed themselves to be recorded by anyone during their concerts. That is remarkable by any standard. In the same way, he shares his knowledge of audio design and actually encourages it at Amp Camp and such. 

 When building his B1K preamp, which uses a DHT (SP1), you just can't ignore the great sound in spite of the fact that the SP1 tube is by no means the last statement in tubes. I have actually built other one designers' concept of this tube for a preamp, and guess what? Doesn't sound as good, period. I believe it is because Nelson uses matched transistors instead of an integrated circuit. Anyway, the beauty of kits is that you have more control over what you prefer. 

 Maybe this thinking translates to consumer products as well?

Don't mean to derail the thread here, as I am interested in other peoples' experience with the big NP amps.

Agreed with @lucky_doggg7 - you unleash full potential when you pair a pass amp with a pass preamp. When I bought my XA30.8 I was driving it initially with the Rogue RP-5 (previously mated with ST100). Replacing the RP-5 with Pass XP-12 took my system to another level. 
Back when I had my X250.5 I used Audio Research LS-25 and Ref1 preamps with it. I recall it sounded really nice albeit having a slightly higher noise floor than the solid state combo I’m running now. 

@4krowme

Don’t mean to derail the thread here, as I am interested in other peoples’ experience with the big NP amps.

i have to say, reading your entries on this thread it seems you are doing just that

you have owned pass kits and really old pass stuff, you don’t have experience with modern pass/fw gear, you say you are interested in other’s experiences with big pass amps

given that, it would make sense that you should perhaps say less and read more? this thread and numerous other threads comparing modern pass amps exist on this forum. with many many happy users reporting and discussing their experiences... just seek and you will easily find...

Point taken

here are some very informative threads that i have personally found helpful in the past

https://forum.audiogon.com/discussions/pass-labs-amp-s-what-is-the-best-pass-amp-sound-for-you-from-past-10-y

https://forum.audiogon.com/discussions/are-pass-labs-amps-probably-the-best-ever-you-can-buy

https://forum.audiogon.com/discussions/comparing-the-pass-labs-xa30-5-to-the-xa-30-8/post?highlight=xa30.8%2Bvs&postid=1298467#1298467

https://forum.audiogon.com/discussions/which-amp-would-you-choose-and-why-pass-labs-xa-25-or-first-watt-f8

Much appreciated. I will look into these.

@jjss49 👍

I’ve tried this approach…it was a waste of time.

I have not heard the bigger commercial Pass amps but I just changed over for the season from my Rogue Sphinx v2 to my DIY Pass F6. Despite their very different topologies,Class D with tubes, Class A, they have more in common than different. Mainly I would say the F6 throws a bigger stage and does reveal some more texture and detail. But both are great driving my KEF LS50s supplemented by a trio fo Syzygy subs.

I would consider the change to Pass just that, a change not necessarily an upgrade. But then I don't look at hifi as a competition. Like Nelson P often says, it is just entertainment. It is supposed to be fun.

Audiogon is a little strange in that things here so often get heated, like this is some kind of contest to see who has the best system. Not my view. There are many things to appreciate in many, many systems. My rule is never overstretch your budget because there is fun to be had at all price levels. Building is a lot of fun, better than just spending money. Check out the DIY store if you are into Nelson Pass. An ampcamp amp is a fine little piece of class a equipment within the capabilities of almost anybody who has the will and the time to build one...and you will also encounter a very nice on-line community that seldom argues and always helps.

It’s really amazing that a designer of that caliber would contribute so much to the DIY community. Pass’ love and passion is what drives him and that’s why Pass Labs have been producing such fine audio equipment and have one of, if not the best, customer service in the industry. 
 

But this is a thread where a question was raised about vintage Threshold vs. modern Pass Labs XA30.8.
Comparing Pass kits built by a DIYer to commercially produced amplifiers from other manufacturers is misleading and irrelevant to this discussion. It also won’t help the OP or anyone reading this thread now or in the future. 

Agreed that the F6 is a different model than the XA30 but I disagree about the relevance of who builds it. When the important parts and design are identical I would expect the resulting performance to be too.

i have had the fw f5 and f6 as well as the pass models i mentioned earlier (currently have the int150, xa30.5 and a modded f5 in my collection of amps)

nelson pass has been interviewed many times, these vids are on youtube, he speaks at length to steve guttenberg and others about how each gen of pass amps, different generations of them, and different fw amps are all his playing with available components (especially various transistors, some no longer available) in various ’less is more’ circuits to produce amps of different capability levels and with varying sonic traits... he is very articulate about how different types of distortion leads us to hear certain attributes in the music

there is also a terrific thread on one of the other forums where he directly participates, and he speaks about his take on how various first watt amps sound different within their respective power envelopes...

these interviews are worth watching, easily found on youtube with a basic search, as is that excellent discussion thread where you hear the sound of various of his described by the man himself

audphile1,

  What is your point now? Just drop it. Move on. Grow up.

@4krowme I see I got my point across now. Enjoy!

I've owned the 30.8 amp and it is a terrific powerful amplifier, despite its 30wpc/8-ohm rating.  I also own a First-Watt SIT-2 and F8, both of which are terrific amps and with the right efficient speakers have taken my listening another level higher in terms of micro-detail and sound stage.  My speakers presently are Living-Voice OBX-RW's (94-db 6.-ohms nominal) and all of the above amplifiers drive them well.  The 30.8 was plenty of power for my L-V speakers as even with high levels of listening, it never seemed strained or to run out of power.  And for moderate to loud listening, the First-Watt amps above also work well.  With your 90-db Gibbons, I suggest that if you like to listen moderately to loudly, you consider the 30.8 over the First-Watt amps.  You should consider headroom and crest factor in your listening and based on your speaker efficiency, choose an amp that will not be taxed at louder volumes.  Remember that at your listening position, your SPL may be down ~7-db, and you definitely want ~6db or more for headroom on peak music.  In my experience with my L-V speakers, the 30.8 came really close to both the First-Watt SIT-2 and F8 in terms of micro-detail other areas important to my listening, however I sold the 30.8 since I really didn't need it with my soon to have new 106-db 16-ohm single-driver speakers.  Good luck in your quest for a new amplifier to power your Gibbons !   

ANY  of the newer Pass Labs amps are better than ANY of his old amps.  I live 30mins from the factory.  He told me himself!

i think @liquidsound ’s post highlights a very important point

and that is that amps of certain power levels do better or worse within some range in their power band -- for instance, using high efficiency speakers with paper cone drivers etc, very sensitive to that first watt, fractions of the first watt they ever get from the amp (btw - that’s the reasoning behind the choice of name, for those that didn’t realize...)

versus something like a modern x250.8 - designed to deliver 250w into 8, 500w into 4... amps like that operate in their sonic sweet spot when they are doing some real work, and they are at their best, they show the strengths intended by the designer when they are delivering some serious current, applying their high damping factor on woofers that need it, and so on.... you get my drift...

so given the wide range of amps offered by pass, from the (relative) fleawatt fw’s to the mega x series amps, one still needs to think carefully about speaker/room matching -- that is the key to sonic happiness

all the above said, it is also important to note that the smaller xa series amps, in my opinion, give somewhat the best of both worlds.... they are rated very conservatively at 25-30 wpc but can actually deliver well over 100 wpc on transients....

@jjss49 What's the lowest-powered Pass you've used to drive (successfully) a Harbeth 40.x?