Loudspeakers Lament
by: Nelson Pass
CLASS A or CLASS A/B……… will Audiophiles ever evolve to a Classless Society? Is Class A amplification superior and preferred to A/B? The answers to these two questions are a definitive: Not Likely And Not Always And the slightly longer … Continue reading
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The Sweet Spot
by: Nelson Pass
Introduction Every audiophile understands the concept of the “sweet spot”, that happy balance of conditions that elicits the best possible sound. It can be a particular listening spot, the best positioning of loudspeakers, or the fortuitous combination of components which … Continue reading
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Power Supplies: Commentary for Consumers
by: Nelson Pass
Intro: Electricity and Hydraulics Lots of people don’t understand electricity, but they do understand plumbing. Hydraulics provides a good analogy in understanding basic electrical flow. Wire is a pipe. Water pressure is voltage. Water flow is electrical current. Lakes and … Continue reading
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Audio distortion and feedback
by: Nelson Pass
Audiophiles seem to revel in minor controversies – vinyl vs CD’s, tubes versus solid state, capacitor, wires, magic dots… and negative feedback. At one extreme, the position is that “feedback makes amplifiers perfect”. At the other extreme, “feedback is a … Continue reading
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Leaving Class A
by: Nelson Pass
The meters on our amplifiers are different. They reflect the current consumption of the amplifier, and when the amplifier is operating, they don’t go down to zero like the meters on other amplifiers. This is because the electrical current consumption … Continue reading
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Like Peanut Butter and Chocolate
by: Nelson Pass
Sometimes two designs complement each other so well that you are surprised they weren’t invented together. So it is with the X Super- Symmetric amplifier and the Aleph single-ended Class A output circuit. The Super-Symmetric “X” amplifier repeatedly demonstrates the … Continue reading
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Trouble shooting for dummies
by: Kent English
Pre-Amplifiers Within the Pass Labs pre-amplifier family we typically see two installation errors, both involving cable issues. The most common error concerns improper sequence of cable connection for our pre-amplifiers with dedicated outboard power supplies. The last cable attached to … Continue reading
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Ground Loops
by: Kent English
Introduction Your brand new component is hooked up, fresh from the box, and the first time you power it up is a sonic disaster; it hums, it buzzes and in general sounds absolutely dreadful. Glaring at your equipment or dealer … Continue reading
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Zen Amp & Bride of Zen Preamp
by: true-apex-admin
Mark Lamb’s Balanced Bride of Zen Pre-amp and Zen Power Amps I have built two Nelson Pass designs, Balanced Bride of Zen preamp and two Zen Power Amps, and am very pleased with the end results. I have to thank … Continue reading
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Super Symmetric Amplification
by: Nelson Pass
U.S. Patent # 5376899 describes a new amplifying circuit topology that takes advantage of the character of special matched balanced amplifiers that are cross-coupled to provide cancellation of distortion and noise. The result provides high performance with very simple linear … Continue reading
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Single-Ended Class A
by: Nelson Pass
Single-Ended Class A amplifiers have certainly hit it big in the four years since we began testing the first Aleph 0. So is this just another audio fad, or is there something fundamental about this kind of design, justifying a … Continue reading
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Phase coherent crossover networks
by: Nelson Pass
Drawings by Kirk Rader. The importance of phase response in the audio chain has been brought to greater focus recently by equipment claims of phase coherency, (the output signal has the same phase relationships as the input signal). It is … Continue reading
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SPEAKER CABLES: Science or Snake Oil
by: Nelson Pass
Speaker Builder, 2/1980 AUDIOPHILES RECENTLY BEGAN re-examining the performance of every link in the audio playback chain, and before long their attention turned to the lowly loudspeaker cable. In response to demand, a number of companies are producing or distributing … Continue reading
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Cascode Amp Design
by: Nelson Pass
Introduction Lowering distortion in power circuits without compromising their transient response remains a primary problem for designers of audio power amplifiers. Until fairly recently, the favorite technique for removing distortion components in linear amplifiers was to cascade many gain stages … Continue reading
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