Passlabs Aleph 1.2 with CJ Tube 17LS/16LS Preamp

Aleph amps (I have an Aleph 4) have all the bass extension you could want. The bass is very deep and would easily surpass the extension provided by the McCormack DNA-1. What the Alephs do not have is the powerful,extremely dynamic, explosive mid-bass that passes for extension, but is not. With the right speaker, these amps will easily rattle the walls, floor and windows with deep bass. While the Alephs may be somewhat of an impedance mismatch with their 10,000 ohm input impedance, they work well with many other tube amps, such as CAT and even Audible Illusions Modulus 3. I have auditioned the Aleph P with the Aleph amps and felt that their were better choices than that preamp for my Aleph 4. I auditioned the Aleph 1.2's before buying the Aleph 4. Even though I have no complaints about the Aleph 4 in the bass, I recollect that the Aleph 1.2, which was twice the power, moved significantly more air in the bass. Since the Alephs are quite neutral and refined, even they give you quite a bit of subtle detail and soundstage etc., they may not have the greatest synergy with warm-sounding equipment like Conrad Johnson preamps. You might look at preamps which call a little bit of attention to themselves, like the Hovland. It is still quite neutral, and quite liquid through the midrange, but the highs are quite detailed and spotlit. However, be sure to check out the bass of the Hovland. I found it to be significantly rolled off.

I find the B&W sound to have plenty of mid-bass, not much bass below that mid-bass peak and a balance which favors the upper mids and highs. Generally, I have found this balance to be fatiguing in the long run as the emphasis of the upper mids and highs is quite evident and not natural. However, there are many who favor this sound. The Aleph 1.2 might have synergy with this speaker, since its character is the antithesis of this kind of sound. Any problem that I have had with the Aleph has had to do with it being so smooth that the upper mids and highs are sometimes too soft. This will not be a problem with the B&W, so these might complement each other quite well.

John_l,
Restating what I said previously, I agree that if you are looking for bass slam there are many better choices other than the Pass Aleph amps. A good example would be a Plinius amp. They have such an iron-fisted quality that is almost shocking in their impact. But, having owned a Plinius, I know that, even when just considering the quality of these two amps in the bass alone, the Aleph will give you far less slam, but much more extended, much more tuneful bass than will a Plinius. Considering the McCormack DNA 1: Yes, it has much more bass slam than the Aleph series, but if you audition both side-by-side with speakers and electronics which do a good job of reproducing the entire frequency range, I think you will find that there are few amps if any which exceed the Pass Alephs, particularly the larger ones, in bass extension. Then, when you look at these amps in their entirety, versus the McCormack DNA 1, for example, with regard to high frequency extension and detail, soundstage and neutrality, I don't believe you could rate the McCormack in the same league with the Pass Aleph. I am not disparaging the McCormack. It is a very good amp and an excellent buy when you take into account its price point. But as good as it is, it is an amp built to a price point. IMO, the Alephs are built to compete with the best available, even if they don't offer the best bass slam in the business.

Arupg,

I have a friend who biwires his Kimber Select 3033 from his Aleph 4 to his Vandersteen 3. He uses KS 3033 on the treble and Kimber 4TC on the bass. His preamp is Audible Illusions Modulus 3 (not 3A) and his source is Micromega transport and Forte DAC. Introduction of the KS 3033 significantly improved the musicality of his system and lowered the dynamics from superb to excellent. Treble was more extended and more prominent without being too bright.
My system is quite similar: Vandersteen 3A Signature, Aleph 4, CAT Ultimate and I was using his Bow ZZ-Eight at the time for digital. We both use Kimber PBJ between CD/DAC and Pre and JPS Superconductor 1 between Pre and Power and I normally use a shotgunned biwire Kimber 4TC for speaker cable. When I tried his Kimber KS-3033, it absolutely did not work, so my feeling is that use of this cable is highly system dependent. You won't know unless you try. I think that at least for my taste as well as my friend's, we both found the KS-3033 to be a bright cable, particularly when fitted with the WBT connectors and with less bass than would be neutral. That is why he used it only for the treble. It improved the balance of his system which was a little bass heavy.

As far as whether the Aleph will suit you, I don't know. I think you need an audition. Some say they are quite tube-like (as far as solid state goes). I am not a tube man, so I don't relate to that designation. They have no solid-state nasties. They are certainly never, ever bright. If anything, they are laid back. Overall, I haven't heard a more complete amp, but certainly there are many that I haven't heard. It might be a good combo with the B&W's which I find a little bright. Your CJ might tame the system even more. If you can, go audition before you buy and let us know what you think.

Hi Arupg,

I think the CAT output impedance is around 300 ohms, but I am not sure that I remember correctly. Since I am at work, I'll have to go home to check. If that is the impedance, it shouldn't be a mismatch. Nevertheless, unfortunately sonically, the CAT/Aleph in my system is not a match made in heaven. I have heard the CAT sound better with other power amps such as the Plinius. It is strictly an issue of synergy. As I said before, the Plinius doesn't come clost to the Aleph as an amp, IMO, but it did have better synergy than the CAT. With the CAT/Aleph combo, there isn't really anything wrong, but I have heard the system sound more liquid, more airy and spacious and more dynamic. Since almost any change in any component of the system can upset things, I have taken the attitude that I can improve things significantly by improving my digital source which is my next area of focus. I don't want you to think that my system sounds bad, currently. It doesn't. I don't hear many which sound better to my ears. But I think there is room for improvement. None of what I say reflects on the Aleph 4 as an amp directly. At this level, I believe synergy is more important than absolute quality (if there is even such a thing).

My feeling is that all the Nordost interconnects and speaker cables, even Nordost SPM, roll off the deep bass. If you can, set up an audition between SPM and Kimber 4TC which definitely doesn't roll off the deep bass. Nordost SPM has a gorgeous bloomy upper midrange and high end, but I think you will find that it it at the expense of the lowest notes of the pipe organ, jazz bass, piano etc.

Arupg,

CAT output impedance is 100 ohms.