Aleph Owners and Users...

Are there sonic differences between the different Aleph models (i. e., 0, 1.2, 3, 4 & 5)? If so, what is the best sounding amp. of the bunch, and why? Why were the 0 and 3 the only Stereophile Class A amps? What about the 1.2, 2, 4 & 5s? Does it relate back to sound/performance vs. the other models? Which Aleph model is the best overall? Does anybody have a recommendation on an Aleph model vs. an ARC V100 mkII? Thanks for the help.
Oddly enough I own both the vt100m2 and the 100watt pass aleph 2 monoblocks. I never really decided that I liked one better than the other.

The aleph 2's are the clearest and most detailed amplifiers I have ever heard. they sound like they take less away from the recording than any amplifier I have ever heard. They are dead quiet and have an almost tubelike midrange character. The midrange is extremely detailed. My old McCormack DNA1/RevAGold had a very very slight electronic 'haze' compared to the alephs. It was more gutsy sounding though. Spectral amps are in the same league, but a little cooler sounding. Krell amps have a sense of forced detail and metallic tinge by comparison. You can hear detail to a fault with the alephs. You hear things like singer's taking small breaths, brushing their hair, fingering the microphone etc. They are ruthless with bad recordings - most rock albums for example sound a little thin and raggedy with the alephs. Jazz recordings sound superb.

The vt100m2 will give you the inimitable 'tube aliveness' and take away some clarity and detail. It is extremely clear for a tube amp and captures the 'magic' of voice, electric guitar, and wood instruments a little better. More palpable presence. The vt100 has a larger soundstage, but the alephs have a more exact one. You can place a well recorded voice to within a few inches in the room with the alephs, but it's more like a foot or so with the vt100.
I've used my two amps with several different speakers and some were better than other's. Generally the alephs shine with very detailed, less power hungry speakers such as audio physic and magnepan 1.6QR. They don't have the raw power of solid state amps such as the mccormack. The 100w alephs actually have weaker bass than the 100w vt100m2. No question about it. The vt100 is more forgiving of both equipment and media. It sounds great with any speaker. It's really hard to NOT get a great sounding system with the vt100m2.

To summarize, if you're looking for great tube warmth/aliveness with unusual clarity, go with the vt100. If you're looking for amazing detail, clarity and spooky soundstage placement, go for the alephs.

I have heard the 3, the 5, and the 2's on different occasions. They all sounded the same. I think it' s just a power rating difference. The 0, the 3, and the 1.2's are all stereophile class A. I suspect the others being left out was just a limited review space consideration.

Vote for me !
I owned the 0's and 2's and heard the 3's and 1.2's in other systems I know well. They all sounded great. The problem with the whole series of power amps was that at every power level they drew an enormous amount of power from the wall, and produced an enormous amount of heat. By the time I felt I needed the output of the 1.2's, I also felt they ran too hot, drew too much power, and were too heavy--oh, yes, they also had the off-on switch on the back to make it worse and discourage you from turning them off. But the sound quality on every pair was superb and very similar, given their power limitations.
I have an Aleph 4 (100w/ch in one large box) and love it. Its the truest sounding amp I've owned so far. MGottlieb is right, though, they really use a lot of power and generate a lot of heat. Its no surprise, they run "pure class A", no switching power supplies or other gimmicks to achieve "sort of class A". Thats why they sound so good. They are essentially a 2 stage triode design with lots of output transistors in parallel to get 100w (in the case of the Aleph 4). I just bought a small whisper fan and all is well.
I owned the 3 and then got the 2s. Surprisingly the 2s are not that much more powerful than the 3. The bass was fuller, and I could play a bit louder. As far as improvments that's about it. I think that the 3 may edge out the 2s in transparency, the 2s sound a little dark to me compared to the 3. If you can live with 30 watts, then the Aleph 3 has got to be one of the best buys in high end.
I own Aleph 3's and have been told that Aleph 5's are essentially the same design with more power, and the further plus of accepting XLR connectors. What I can contribute here is mainly a question: do the Alephs other than 3 and 5 have only two gain stages? If not, some difference in quality of sound should be expected, maybe better for some aspects, worse for others. I guess the Pass Labs Website no longer discusses the Alephs. Too bad.
A further remark: I'm using two Alpeh 3's as monoblocks, with 8' interconnects and 18" speaker cables, and have made direct comparisons with a single Aleph 3, 1M interconnects and 7' speaker cables, and the benefits of going to monoblocks are tremendous! I'll never use anything but monoblocks and short speaker cables ever again. The improvement that monoblocks (with the short speaker cables they permit) bring is likely to be far greater than the improvement gained by moving from one model to another, IMHO.
So Tom, when you say you are using the 3's a monoblocks, does that mean you are doing a vertical bi-amp arrangement, splitting the input into two channels and driving the bass with one and the mid/tweet with the other channel?
Tom: To my knowledge, the Aleph 3,5, 4, 2, and 1.2 all use 2 gain stages. The 0 and 0s used three.
Drubin, I don't have the option of biamping or biwiring with my Quad ESL 63's. But for anyone who does, I'd certainly give it a try, though I'd ask Nelson Pass about it first. I don't think there's any risk to amps or speakers, but there still may be wisdom to be gained as to how well various arrangements work. I'm simply connecting both inputs and outputs in parallel. The biggest benefit, I think, comes with the short speaker cables that monoblocks permit. But once you have that, why not try for even more? Nelson Pass is good about responding to emails, in my experience. Look at to get their email address. Good luck!
Pardon my density here, but if you can't biamp or biwire with your Quads, how are you using the Aleph 3's as monoblocks? It's a stereo amp without bridging capability, is it not? Maybe you are using one channel per amp...
No density apologies called for, I should have explained (if I didn't). Following Nelson Pass's advice, I'm paralleling both inputs, through Y-adapters for my interconnect cables, and outputs, by bundles of wire between L/R binding posts. I'm told that I MAY get some advantage, with reactive loads, in regard to transient responds, by using both channels of the Aleph 3's, and since I can't turn one of them off, that's what I'm doing. The benefits of short speaker cables--and they are huge, IMHO--can still be had by leaving one channel on each Aleph 3 empty, and maybe it would sound just as good, who knows? (Maybe Nelson Pass would, and he did recommend the parallel wiring using both channels.)
I use the Aleph 2 to feed the top of the Apogee Mini Grands. all i can say is MAGIC!
Thanks for the explanation, Tom.
I have owned the Aleph 3 and currently am using Aleph 2 monos in my system. I had a period of around 1 month that I spent A/Bing the two in my system (essentially trying to justify the huge jump in price). There is definitey a sonic difference betwen the two. The 3 was more musical and for lack of a better term more emotional. It was certainly a little muddier in the low end and was slower to respond to snare drums and other fast and low freq's. The two is more precise, somewhat more analytical (and I mean this in the best possible way) - Nelson Pass can do little wrong in my ears. All that said, I did feel less emotionally taken in by the 2's. I spoke to the guys at Pass during my month and they swore the 2 was every bit as good as the 3, just more of it. I am not sure that I agree in the setting of my own system. I thought the 2's could be a little thin compared to the 3's almost etereal sound when listening to female vocals (what I usually listen to). All that said, I still went with the 2's and am very happy with them. They are alot more capable of driving fast loads (not easy for SE amps). I was concerned that if I ever bought less efficient speakers, I would want the 2's. As an aside, I recently got changed out my KCAG to a Cardas Neutral Ref from my D/A to my pre and that helped alot. It is hard to say which amp is better. I think that is personal preference. The guys at Pass say the 2's are their truest amps of their whole Aleph series. To make a short story long as I have, and I'll stop, I guess the gestalt of this is "yes" they sound different. I'm not sure which is better.
I forgot to add. I think the 1.2's were also rated "A" by S'phile. My guess as to why all of them weren't "A" is that either it would be a little unfair to put all 4 amps in that class, or that all of them weren't Class A quality- and please read what the guys at S'phile say about class "A". Essentailly a cost no object, best possible reproduction of the live event. That's a pretty tall order. They did put the least and most expensive ones in the Aleph line up in the "A" category. All that said they are both (the 3 and 2's- only ones I've auditioned) wonderful amps. I can't imagine getting a new amp for many years if ever. I would pick one that you can afford and that you are very happy with. I think the habit (and I'm guilty of it too) of looking for the "best" often keeps us from enjoying something wonderful that's pretty darn close. Also, sorry to all for my typo in my last post. I meant to type ethereal not etereal. Somewhere out there my old English professors are rolling their eyes and shaking their heads. Peace and Happy Listening!
The others weren't Class A because they were not specifically reviewed. A few things are rated without review, but generally not.