Pass Labs Aleph Question


Was thinking of trying out the 100 wpc aleph 2's with Dunlavy 4a's. I've heard these amps are some of the most natrual sounding amps out there and was wondering how well they performed in the low frequency area. Are they bass shy or can they be authoritative? How do they sound with complex music ? Rock? Thanks
chris96
One of the classic Aleph amps for difficult loads is the 0 mono Series. With it's 3 gain stages it really 'bites'. That's what I like so much much about these tough little amps. Only 2 ways:
Dead or Alive
One of the classic Aleph amps for difficult loads is the 0 mono Series. With it's 3 gain staiges it really 'bites'. That's what I like so much much about these tough little amps. Only 2 ways:
Dead or Alive
I am using an Aleph 30 to drive the woofers in Zu Definition Pros. For 40Hz up I use a Red Wine Audio Clari-T with only 6 watts of output. I have found that you can alter the ratio of investment between amplification and speakers if the latter are very efficient. I'm driving $10K worth of speaker bi-amped with an $1100 amplifier investment and no compromise whatsoever. This provides better results than you will ever get driving $5K worth of speakers with $5K worth of amps.
I've owned the Aleph Os (the stereo version of the mono block) for years. It was driving my Thiel 2.2 for a while. When I upgraded to the Thiel 3.6, the Aleph Os was not powerful enough. But I kept it because it was just a very sweet sounding amp. It ended up in my second sytem powering a pair of Unity Audio Signature 1s. (Sonic Frontier SFT-1/ML #36DAC/ARC LS-1.) The system was very musical and the midrange was just awesome. Actually my wife prefer listening to this system over my main system.

I took down that second system and converted the room to the baby's room two years ago, and the amp has been sitting inside its crate in the garage. I started putting everything else for sale, but just could not bring myself to sell the amp. The only thing that would get me to sell this amp would be to buy a pair of the Aleph O monoblocks.

Recently I've decided to look for a new pair of speakers to replace the Thiel 3.6, and also to get a Pass X350.5. It just dawn on me the other day that I can use both the Aleph Os and the X350.5 to biamp. I think this would be a killer combo. We'll see. I have narrowed down my speaker choices to three, but have not made a final decision yet.

FrankC
A great match I found for the 4a's was Classe. There seemed to be a definate synergy between those two lines. Try to find a Classe CA400. That was the best sounding of the CA series, has a boatload of power (400 watts), and runs cool.
I owned Aleph 5s and their bass is excellent, but they don't have that iron-fisted slam thing going that some other solid state amps exhibit. As a point of reference, at orchestra concerts do you hear authoritative bass?
I've owned Aleph 0's, Aleph 1.2's, Dunlavy 4's, Dunlavy 5's and Dunlavy 4a's. In my experience, if you want satisfying, well defined, articulate bass response out of the 4a's the Aleph 0's are your best all around bet. Of the Aleph series the original model, the 0, is the most well rounded of the bunch for most speakers. The Dunlavy's, while quite efficient, still needs the amp to take control of the woofers. If you're willing to do without the above described bass response, the later Alephs have a "sweeter", slightly warmer midrange than the Aleph 0. Be prepared for the heat these cubes throw off- the 1.2's being the largest are sufficient to effectively heat a small studio apt.
I have an Aleph 5 at the moment driving a pair of Sonus Faber Grand Piano floorstanders. I don't agree that the low end is weak - I think it really depends on the sensitivity of the speaker and the cables used. I am using Audience AU24 speaker cables and Nirvana SX interconnects and love it. Having said that I am tempted by a pair of Aleph 1.2s but I know I don't need them........
I'm currently using Aleph 1.2 monoblocks on Apogee Studio Grand ribbon speakers (with Aragon Palladium II monos on the subwoofers). These run around 5-6 ohms. Prior to my acquisition of the Studio Grands I ran them with Apogee Duetta Signatures (3-4 ohms).

Both speakers have fairly constant mostly resistive impedance curves and the minimum impedances lie right in the optimal portion of the Aleph 1.2 power/impedance curve.

The Alephs are magic on both speakers. The Studios have much better dynamics than the Duettas and the Aleph/Studio combination provides slam as well as sweetness and delicacy.

The downside is that they are space heaters. Each amp pulls a constant 600 watts from the power lines and most comes back as heat. I need suntan oil and a beach chair for winter listening sessions when the A/C is off.
I heard the Dunlavy 4's with a pair of Pass Aleph mono's running either 90 or 100 watts per channel. Nice but nothing special. Later heard the very same speakers with 4 200 watt mono's of a much lesser pedigree and liked them way better. I think the Pass x1000 mono's are amongst the best amps I've ever heard.
I also have a friend who runs an Aleph 4 with Vandersteen 3's into a room which is 27' x 18'. The ceiling ranges from 8' to 9' directly above the speakers, but at the other end of the room, the ceiling is over 20' high at its peak (cathedral ceiling). This room is open to other rooms on either side. He likes his music extremely loud and the Aleph has no problem with this setup, i.e. it never sounds thin or under-powered or gives any discernible sign of strain. It is my perception that the Aleph 4, being the last Aleph produced, may have better bass than the Aleph 2, but since I have never heard the Aleph 2, I arrive at this mainly from matching my Aleph 4 experiences with the comments of others about the Aleph 2.
I have the Aleph 4's which are a stereo version of the Aleph 2's. I corroborate those who say that the Aleph
amps are some of the finest ever made. They are extremely neutral, deliver tremendous detail in the highs while always sounding natural and unforced. Even the most minory colorations which I find in my system are always proved to exist elsewhere, not in the Aleph 4's. I use them with the inefficient, 6 ohm Vandersteen 3A Signature in a romm which is 22'x12'x8' and which is open to adjoining spaces. There is no bass problem. Bass is extremely deep and will do any pipe organ recording justice. This amp can rattle floors and windows if you are into that. What it doesn't do is give you the ultimate bass slam. The bass is not super-tight and punchy, but who cares! It is a wonderful amp in every respect. I have heard the Pass X series (X350 and X250). In my opinion, they don't compare for naturalness and for absence of all electronic artifact. Sorry Pass Labs, but that is my opinion. The fact that they developed the super-expensive XA series, followed by the X+ series in order to bring the sound of the Aleph to the X series would suggest that someone was not completely satisfied. I say just save your money and buy an Aleph. From some of the posts here, you might want to stick with the more powerful Alephs. I have heard the Aleph 3, the Aleph 4 and the 1.2 (200W monoblock). The 3 did sound a little underpowered in certain situations, but it is also a wonderful amp.
I have 2 Aleph 5's and they are one of the finest sounding amps I've ever heard. Drawback, only sound good when warmed up (at least an hour), will double your electric bill if you leave then on and aren't suitable for difficullt speaker loads. Match then up with some fairly efficent speakers. I have B&W Nautalus 802's and they work fine.
The room was 18x25. I went from the Aleph 2s to the BAT VK150SEs and the bass as well as everything improved quite a lot. I really do love the Aleph sound, I just don't think the Dunlavys are the best match. I had better luck with the Silverline speakers with the Aleph amps
Im with you TD. I have found out that if the 4a's arent set up properly or the room isn't working with them, you can have a krell fpb 600 hooked up to them and the bass isn't going to be right. Good thing for me, I have an ideal setup, a fairly small room 13X18 with the speakers on the long wall. I actually was between amps and had to borrow a 5 channel B&K av 5000 amp rated at 110 wpc and the bass was fine. So I can't really see the aleph 2's letting me down unless they're just bad at reproducing bass. Ejlif, How big was the room your Dunlavys were in?
I also had the Aleph 2s with Dunlavy 4s. I went from the Aleph 3 to the Aleph 2s on the Dunlavys. I thought the major improvment was in the bass going to the 2s. There was always something I liked better about the sound of the Aleph 3, there just wasn't enough power for the Dunlavys though, and even the Aleph 2s with the Dunalvys wouldn't rock the house. I consider the Aleph 2s to be a weak 100 watts. They are great sounding amps though, just not powerful sounding amps.
I have Aleph 2s driving Vandy 5As. The 2s were driving SC IVAs before that and did a very job of it. The 2/IVA combo was set up in two rooms. The first one was 14x16x8.5 feet. This setup, on a short wall, (with Wadia 860 direct) was really good, bass measured to the 25 HZ area and was fairly flat.. The IVAs replaced Thiel 3.6s and are a better speaker IMO.

Later the same combo was part of a full HT setup in a 17x27x10 room on a short wall. With more room, the SC IVa were excellent in many areasr and had a small sweet spot. BUT, I never got flat bass. Later I added a REL Stentor III sub. I moved things all over and there were always holes. The kind I just could not get around. Fantastic HT speaker BTW using the processor Xover with sub.

In short if the SC4As work in your room, the Aleph 2s are excellent with the Dunlavys IMO.

I heard that Dunlavy had Pass amps (forget which ones) in house during product development.

I am looking to replace the Aleph 2s but it will cost me big bucks.

TD
I had a pair of Aleph 2's and found that they were wonderful, in bring you closrer to the music, as you put it. The Mid's are wonderful, High's to die for, they were matched prefectly with a pair of speakers custom made from Celestial Audio in Phx. But in my Exp. of you want Low end, and you have ineffienct speakers. The X series 350 may give you the punch your looking for. or the .5 would give you punch and the aleph close to the music.
I primarily used the Silverline monitors, but tried out the amp with all of the following.

Silverline SR17 monitors (89db)
Boehlendar Graebner (can't recall the model - around 94db)
Klipsch Heresy's (94db)
Klipsch LaScalas (104db)

I did not like it with the horns as I found it too harsh coming from tube amps, so stuck with the Silverlines where it sounded quite good indeed. The issue of the bass and power became very apparent in switching the Aleph 5 off with the very modestly powered Quicksilver Mini-Mites (35W with KT88s) which gave the SR17s what occured to me as a firmer grip throughout the range, including bass to write home about coming from those small monitors.

Marco
Thanks twice, hehe . Im currently useing an x-250 and its a great amp, but im wondering if the two gain stage -single ended design of the aleph series would bring me closer to the music. It seems like the newer Pass amps are trying to bring back some of the design philosophy of the Aleph amps yet one of the reviews on the Pass x-600 claims that " The X-600 handily outclasses the Aleph 1.2's." That statement seems to contradict where Pass is going with their newer designs.

Im sure 600 watts will sound better than 200 watts on inefficient loudspeakers that demand huge power reserves but on efficient systems where all that power is not needed, does the simpler design of the aleph stand out. Im looking for some honest opinions.
I cannot speak for the Aleph 2, but I owned an Aleph 5 for a while. The midrange on that amp was wonderful, but the low end, in fact, was its weak point, to my ears and in my systems. It was not terribly articulate in the bass and did not grasp the lows with the same authority it did the midrange. I also felt it was underpowered at a rated 50 watts (which I think is exaggerated). From all I've heard the Aleph 2's are better in every way, and even the less expensive 3's and 30 have better lows than the 5. The Aleph series in general are supposed to all excel in the midrange. Mind you, I am not saying the 5 is a dog...in fact I liked it very much. It did do complex music quite well indeed. I just wish it had more power for the large space I was using it in. I thought it worth mentioning that weakness should you look elsewhere in the Aleph range.

Marco
The Aleph series serves you the music the only acceptable way:
good signal in ---> good signal out and the opposite of it, too. It can do everything, when the right speaker is connected. From what I heard, most people used simply the wrong speakers with them, they were never made to drive ultra low impedances, but I heard from a user, he drives Apogees with Pass O monos and he is happy with them. For me, these are one of the best sounding amps ever made ( listened to the latest XA, not better from sound IMHO ).
And yes, complex music is their strength and with rock music they sound simply amazing.
The Aleph series serves you the music the only acceptable way:
good signal in ---> good signal out and the opposite of it, too. It can do everything, when the right speaker is connected. From what I heard, most people used simply the wrong speakers with them, they were never made to drive ultra low impedances, but I heard from a user, he drives Apogees with Pass O monos and he is happy with them. For me, these are one of the best sounding amps ever made ( listened to the latest XA, not better from sound IMHO.
And yes, complex music is their strength and with rock music they sound simply amazing.