Pass Aleph


Is it possible to "bridge" a Pass Aleph to MOno? How does one do it? What are the pros and cons, esp. related to impedence of the speaker? Discussion is welcome.....
ivanj
Why not ask Nelson Pass? He's a source you can trust, and in my experience you always get an answer back from him in a week or less. I think the web site is www.passlabs.com.
Here is the kind immediate rely from Pass Labs:
"While not bridging in the classic sense, what people sometimes do with the Aleph amps is to run the speaker outputs in parallel, thus delivering one channel worth of signal at a higher current level than can be obtained using the amp as a stereo unit.
Best regards,
Peter Perkins, North American sales, Pass Labs and Volksamp"

My question to savvy Audiogoners is: how do I effect a parallel output? What does the wiring diagram of the amplifier outputs to the speaker look like?
Got to Love these guys(girls) at Pass, thats customer service.
Here is the kind immediate rely from Pass Labs:
"While not bridging in the classic sense, what people sometimes do with the Aleph amps is to run the speaker outputs in parallel, thus delivering one channel worth of signal at a higher current level than can be obtained using the amp as a stereo unit.
Best regards,
Peter Perkins, North American sales, Pass Labs and Volksamp"

My question to savvy Audiogoners is: how do I effect a parallel output? What does the wiring diagram of the amplifier outputs to the speaker look like?
Dear Ivan,
You are kind to promote our customer service so prominently on Audiogon. To elaborate on my reply, visualize the two speaker outputs on the Aleph stereo unit (Aleph 3, 4, or 5): there are two red and two black posts. Further visualize two bare wire pairs (for the purpose of this illustration): at the amplifier end, you connect one strand from one of the pairs to each matching output (red and red and black and black), then, at the speaker end, twist the two wires from the red outputs together and hook them up to the red binding post, and do the same with the black outputs and the black binding post. You now have, effectively, one channel (mono) from the stereo amp.

The next step is to consider the INPUTS to the amplifier: you will also need to separate these from your preamp or source into a parallel configuration for EACH of your now "monoblock" stereo amplifiers. In other words, visualize red and black outputs from a selector on a preamp. You will take the "red" and feed BOTH inputs on one of the "monoblocks" with this signal. This will require some sort of a Y or splitter. You would also take the "black" and feed BOTH inputs on the other "monoblock" in the same fashion. Thus, you have taken half of the output signal and fed it into one amplifier, and the other half and fed it to the second amplifier.

If you are attempting this with the Aleph 4 or 5 you have a choice of XLR or RCA inputs; the Aleph 3 only accepts an RCA input.

OR....you could round up a nice used pair of Aleph 2 monoblocks from one of the many reputable sellers on Audiogon and make your life easier, and arguably get a better result...

I hope this is a more explicit response than my initial one.

Best wishes,

Peter @ Pass
Peter,

Why don't you introduce people to get a pair of Aleph O as this still the best amp amongst of Aleph series, right? Though the power is not its strength but still provision of clarity, 3D, dynamic, sweet and transparent while driving my Duntech Princess.
Dear Bigfinger2000,

Your point is very well taken. From our experience the jury is still out on the 2- or 3-gain stage Aleph amps, with the 0, the 0s and the Aleph 1 being the original 3-stage models. Some people prefer the additional control and dynamics that the third stage offers, while others appreciate the elegance and simplicity of the 2-stage designs (Aleph 1.2, 2, 3, 4 and 5). I was actually only responding to the question about making the stereo amps mono, but, you're right: Ivan could actually look for one of four different Aleph mono models: the 1, 1.2, 2 or the original 0.

Peter
I started using arpanet years ago for academic questions; then easynet; then usenet, and finally the WWW and, yes, Audiogon and Audiogoners. We are very lucky to be living in this age. And, in addition, folks are communicating with each other in an informative and truly supportive way. Finally, we are VERY lucky to have Pass products and support, even after the sale.
This is very interesting to read.
I own these Aleph 0 monblocks and maybe is my opinion interesting for you:

Pass Labs: Aleph 0 mono amps

All over the world, serious listeners are coming to recognize that single-ended amplifiers capture the subtle expressions that are the soul of music. The remarkable low-level articulation, portrayal of dynamic nuances, and fine resolution of textures communicated by single-ended amplifiers truly makes the magic of music come alive in the listening room. Resolution of detail is often confused with a bright, etched presentation that artificially emphasizes delicate transient detail. Such amps advertise transients on giant billboards. For me, the concept revolves around the ability to hear into the music and follow the attack and decay of various instrumental phrases and nuances organically woven into the music's fabric. Proper reproduction demands that detail remain discreetly in the background until I choose to focus my attention on a particular instrument in a complex passage. The Aleph was outstanding in this regard, offering me high-power magnification when I wanted it while preserving the textural delicacy and natural sweetness of the upper octaves. The Aleph's tonal character could best be described as neutral—it didn't tend to soften treble transients. Hence, speakers with an emphasized treble had no place to hide. Neither did it inject a sense of warmth into the orchestral power range. The Aleph in no way beefed up speakers with lean tonal balances: their lower mids remained anemic. In concert with its SE triode cousins, the Aleph brought to bear upon the core of the music two dramatic attributes. Harmonic purity, from cello to soprano voice, was startlingly more convincing than that afforded by any other solid-state amplifier I've heard, with reproduction of violin overtones especially noteworthy. This is a hard enough task for any amp; solid-state designs typically come up short, managing to sound like so many sewing machines whining in unison. Not so the Aleph 0. While refusing to romanticize textures, it infused harmonic overtones with a natural dose of liquid gold. The overall perception was of raw speed tempered by a fistful of harmonic tonic. The Aleph's ocher SE triode-like sonic aspect had to do with its reproduction of music's microdynamics. Breathing a spark of harmonic life into instrumental outlines is part of the magic of an SE design, and derives from that first watt of power—it propels the harmonic envelope to full bloom. The dynamic microcosm lives or dies by chat first watt, and SE amplifiers possess the purest initial burst of power that anyone has yet to hear. Not surprisingly, the Aleph successfully negotiated the ebb and flow of instrumental outlines, routinely communicating the music's inherent dramatic tension. Soundstage transparency was such chat I was easily able to mentally step into the spatial illusion— image outlines were tightly focused in tidy parcels of listening-room real estate. A large chorus stretched convincingly from right to left of the stage, with a strong sense of image palpability but without smearing individual voices. When using with a good speaker then you can forget the discussion tube or solid state. I have both and I can say: THE PASS ALEPH O IS TRULY A BREAKTHROUGH PRODUCT.