Review: Pass Labs Aleph ONO Preamplifier


Category: Preamps

Ever since the advent of “perfect sound forever” the availability of quality analog reproduction devices has increased. Now that the LP is a dead medium we consumers can finally buy the best equipment ever available. Who ever dreamed Boulder would make a $26,000 phono section? Unfortunately the Boulder is out of reach for most of us. But, there are plenty of other quality phono pre-amps available for the working class.
Within the last six months I replaced my old Krell pre-amp with a line stage KRC 2. I loved the sound of my new pre-amp but now I needed to add an outboard phono stage. My brother-in-law loaned me a Krell KPA with all the settings right there on the front of the cabinet. It was easy to use and sounded better than what I had in my old KSP-7b. The fact that I liked it as much as I did allowed me to take my time replacing it.
After a long drawn out ordeal, which I chronicled in a thread on AudiogoN, I bought a Pass Labs Aleph Ono. The unit had been sent back to Pass labs and upgraded by the designer. It took over a week for the unit to break-in to the point where it could be listened to for any length of time. The Aleph Ono was connected to the KRC 2 with a pair of Kimber KCTG interconnect. The Aleph Ono can be run balanced but I have not tried it that way yet. The rest of the system can be seen via the link below. Krell has always been famous for their “bass slam” and low frequency control. They deserve this reputation but they have nothing on the Pass Labs phono stage.
The bass is tight and fast. The midrange is smooth without any apparent frequency fluctuations. The one drawback in my mind is that the treble seems slightly rolled off in the upper most octaves.
The soundstage is quite possibly the strongest area in the Aleph Ono. Imaging is tight and small. Instruments and voices are not smeared across the space between the speakers they are defined with plenty of air around them. To repeat the often over used cliché, I heard things I haven’t heard before. I listen to a pretty broad range of music, anything from classical to classic rock and whatever might be found in between. I don't care if the recording is of Flutes or screaming guitars I want them to sound real, like live music. In Tchaikovsky’s Symphony No. 6 (Karajan) it was possible to count the violins and French horns. The depth of the recording continued back farther than I am accustomed. On Hoyt Axton’s “Fearless” the track Gypsy Moth was eerie. It was so close to sounding like someone was in the room playing an acoustic guitar and singing with that powerful baritone voice. Elvis' first album with RCA "Elvis Presley" was amazing. Heartbreak Hotel never sounded like that before. The recording was very well done and the Pass Labs made it come to life (the album, not Elvis).
It might not be a Boulder but the Pass Labs Aleph Ono is worth auditioning for anyone not ready to spend $26,000 on his or her next phono section.

Associated gear
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Similar products
Krell KPA
128x128nrchy
I agree - you might try balanced out. I have one.... send me an email we can talk and post the salient bits...
Nice review I have an unmodified ono and find the same characteristics. It is indeed dead quiet and highly detailed. It doesn't have the tube bloom of my ph-3, but it is a good deal easier to set up (no soldering!), and does have an amazing amount of gain. Pass did a great job on this one. How much did they charge for the mod job ?

I have mine ramped all the way up to 76db of gain. I need all of it to support my .3mv output cartridge. Otherwise I would have stuck with the ph-3.

I bought this to see if it sounded 'good enough' so that I could avoid spending the big bucks on an aesthetix or manley. It sounds more than good enough. A keeper to be sure. Love the build quality. Looks like a military component designed to be mounted on the OUTSIDE of tank.
If I remember right the mods where about $450.00, but don't quote me. Doesn't the sound of your Aleph Ono make you wonder how much better the Boulder can sound.
I believe the update they did to mine was $100 or less. Contact wayne at pass labs with your serial number and he can advise.
Since writing this review I have purchased a 5 meter pair of Purist Audio Design Proteus ICs to run between the amp and pre-amp. The upper octave roll-off I experienced is nolonger there. For whatever reason the PAD ICs have eliminated this. If you have the oportunity to try some of the better PAD ICs you will be pleasantly surprised.