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

I am considering buying Aleph 1.2s to marry with a cj tube pre, the 17LS or the 16LS. The only problem I can see is that the unbal RCA input impedance of the Aleph 1.2s is approx 10Kohms and the output impedance of the 17LS or the 16LS is somewhat of the high side, i.e. approx close to 1kohms.

Does anyone have suggestions how the two of them would sound together? esp with this impedance mis-match problem

Also, any opinions of the Aleph 1.2s with B&W 801s / 802s.
That may not be the greatest of matches. (this is my meaningless opinion only!) Why ?

A) The aleph 2 amps never really seemed to have that much power. Unlike most ss amps, the alephs don't have linear power output respective to load. The aleph 2 put 100w into 8 ohms, but only 160w into 4. I know my 100w arc vt100 had significantly more powerful bass than the 100w alephs. The mccormack dna-1 DEMOLISHED them in the bass department too. Your B&W speakers have wonderful bass. They always seem to benefit from big amps.

B) I found that the aleph's sounded noticably better in balanced mode.

C) CJ gear is more of a warm/glow sound rather than high resolution. I found when I put a tube preamp (AI 3a w/NOS telefunken) in front of the aleph's, it seemed to take away their spooky clarity. Not a good match at all. I also found the vk-30Se/aleph 2 didn't sound quite as good as the aleph P/aleph 2. The 30SE did WONDERS for the vt100 though! I have not yet tried my new BAT vk-5i/NOS with my aleph 2's. I plan too in the near future - will report !
You're correct about the impedance issue; it's not a good match electrically. It also depends on how difficult your speakers are to drive; the B&Ws are pretty demanding in this department. With your proposed setup I would expect a lean bass presentation and possibly a rolled off high end as well. Good luck finding the right amp. I did just read a good review in the Absolute Sound of the Marsh A400 which is a bargain, i.e., $2000 for a 200 watt amp, and possibly a better match for the CJ pre.
While I agree that the cj/Pass Aleph combo is not the best way to go because of the impedance mismatch, I do want to point one thing out. Arupg is considering Aleph 1.2's not Aleph 2's. While they share the same topology, the Aleph 1.2 is a whole diffent animal than its little brother. The 1.2 is 200 watts into 8 0hms and about 300 into 4. Having spent time with both amps, this extra power seems to make a lot of difference.

I am currently using 1.2's on Wilson speakers and have all of the bass performance you could ever want. It is tight, deep and very controlled. I to have used the Alephs with BAT preamps (the VK-5i and the VK-50se) and found it to be a pretty synergistic combination (the 50se was the better match). Like John, the best results I got was with a Pass preamp (which is not surprising given the natural synergy of using components from the same manufactuer. The combination of a Pass X0 pre with the 1.2's is hard to beat.

The 1.2's will do an excellent job of driving the B & W's but I would not recommend using the cj preamp with them.
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.
I have a pair of Aleph 2's that I use with Talon Audio Khorus's . At first I was using an audible illusions mod 3 a with this setup. I had loved the sound of the mod 3 with my previous amp (McCormack DNA .5)nad it sounded pretty good with this setup too. However when I switched to the Pass aleph P there was a night and day difference. The bass was more extended and tigher the midrange clearer and the highs smother. These observations have led me to conclude that perhaps triode tube preamps are not the best match for the alephs. I feel the Alephs work best with the Aleph preamp. For a tube preamp they might not be the best choice.
I agree that the 200w aleph 1.2's probably have considerably better bass. I have only used the 100w aleph 2's. They have the same power rating as the 100w stereo aleph 4. My point, and I do have one, is that compared to other 100w amps, the aleph's seemed weak in the bass. Somewhat related, I found the 185w mccormack dna1/reva was much much stronger. This was into a 4 ohm load audio physic virgo and 4 ohm magnepan 1.6. At his impedence, the aleph 2 is putting out 160w, and the mccormack 375w so the difference in bass is not surprising.

I do like the aleph 2's quite a bit. Strong bass just doesn't seem to be one of their characteristics.
I had a long discussion over phone with Passlabs people and they reckon and strongly suggest that even a 1,000 ohms output impedance out of any preamp will not upset the Aleph 1.2 whose input impedance is only 10,000 ohms provided, a quality interconnect like Cardas "golden ref" is used. Yes - the extra warmth of the cj might be too much. I was speaking to another ultra highend specialist who suggested the FM Acoustics new resolution series 155 preamp to go with the Aleph 1.2s. I do know that FMA gear is very neutral, typical of the swiss and they practically thrive on 'neutrality'. Wonder, how this would match? The FMA 155 also have quite low output impedance, typically around 100 ohms.

Also, may I clarify that the Aleph 1.2s I am talking about are 200 watt monoblocks at 8 ohms. These are the flagship ones of the entire Aleph range of amps.
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.
Hey Rayhall,

I think we are in complete agreement on the mccormack verses the alephs. I have owned both alephs and the mccormack. My Mccormack was a hotrodded dna reva/partial gold. It was a great amp. I would take it over any amp on the market except for the alephs. The alephs are the best solid state I have heard. They just have a greater purity if sound than anything I have heard. Every other solid state amp I have listened to has a little 'haze', or worse, a 'processed' sound to it (you know, like an emmylous harris album). The alephs are just pure undistorted sound with walt-disney class holography. I've heard krells, s
pectral, levinson and all. I prefer the alephs to any of them. Just my taste !

On the topic of matching a warm tube pre to these amps. I hooked up my aleph 2's to my avanti centuries last night. I first listened with the aleph P mk2 preamp for a little while. Unbelievable detail but still liquid sounding. If you told me it was a super accurate tube amp playing, I would have believed you.

I swapped in my pre-warmed NOS tubed BAT vk-5i (New sovtec 5881gxc w/ rca nos tubes). The sound was dramatically different. A little smoother, but at a fairly sizable loss of transparency. It seemed that the high frequencies were quite a bit more rounded. It was very easy to prefer the aleph P with the aleph preamps. I felt that the soundstage became quite a bit more rounded. It definitely wasn't a great match. The BAT sounds wonderful with the vt100, but 'just ok' with the alephs. The aleph P was much much better.

Cabling was nordost quattro-fil, spm speaker cable and sony SCD-1 SACD player. It didn't surprise me that this is the setup that Sony used to demo SACD. (with their own crappy speakers of course)

To eat my own words, the bass was quite spectacular. For some reason the avanti-centuries DO display greater bass authority with the aleph 2's than the vt100. I am using different cabling, a different cd player. The vt100 also has svet kt88s in it now instead of 6550's. If I recall, the major difference in bass could be heard with my old mg 1.6QR's moreso than the virgo's. The alephs have unbelievable speed. The tube equipment seems to be swimming in molasses by comparison.
Very interesting Rayhall & John_1:
No, I'm not looking for the last word in bass slam etc. What I'm looking for is overall completeness, i.r. attack, growth of the tone, and decay, all of which are plenty in abundance of a SET(tube)amp. But, the SET doesn't have the extended bandwidth of the Alephs. I'm also looking for holographic imaging, and am a soundstaging freak. I was told my people from KimberKable that using their Kimber Select KS3033 cable instead of the much touted BifocalXL would give me more body, bigger soundstage etc. Is this a fact? I was thinking of considering either the Cardas "Golden cross" or "golden Ref" as speaker cables with my B&W 801/802s. Appreciate your inputs.

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.
Hello Rayhall:
Thanks for the input on the KS3033. I suspected that they could get a bit on the bright side as Kimber claims more air, & more air! Maybe, Cardas either "golden cross" or "Golden Ref" make be the cable for me then. As regards to the Aleph1.2s, yes, I wanted an amp without the usual solidstate nasties (which is the odd-order distortions). How do you feel about your CAT / Aleph 4 marriage, esp considering the low input imp of the Alephs and the fairly high output imp of tube preamps.
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).
I've tried the kimber 1120 i/c's and they worked just fine.

My favorites, of course, are the nordost Red Dawn and SPM. Their inherent quickness and transparency really bring out the pass labs speed. The acoustic zen is a very good speaker cable too. It's not as fast nor as transparant as the nordost SPM cable, but is very smooth and excellent overall. If you are staying with the cj preamp, you should give this cable a try.

Because of their speed and transparency, the alephs seem to benefit from big dolla cables more than most.
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.

CAT output impedance is 100 ohms.
Since your CAT is 100 ohms looking into the low input imp of the Alephs, there should be no imp mismatches here. I've auditioned Nordost line of ICs and do find them a little clinical with certain types of music. I keep returning back to the cardas and find they have "soul" in them. Its just a feeling.