关于胆管和石管的争议

wangxy

手里有一个耳机，播放器推的不理想，于是想买一个耳放，在搜寻的过程中，发现还有胆管和石管之分，而用过胆管的，哪怕是一百多元的，都说好，而买了石管的，有说效果好有说效果一般的，于是心偏向胆管，但是，后来又在百度上看到关的胆管和石管，吵得一塌糊涂，于是我没主张了，为保险还是买了一个石管。后来还不死心，在国外网上一查，其实胆管和石管之争，国外早有定论，各有优缺点，但有一点是肯定的，胆管的意质的确好。于是，下一步还是想买一个便宜的胆管。我把原文贴过来，大家可以看看。
Vacuum Tubes and Transistors ComparedTransistors vs. Tubes – Brief Feature Comparison, adapted from IEEE & Eric Barbour’s 1998 “Cool Sound of Tubes” article.
Vacuum Tubes: Advantages

• Superior sound quality.
• Highly linear without negative feedback, especially small-signal types.
• Smooth clipping is widely considered more musical than transistors.
• Tolerant of large overloads and voltage spikes.
• Characteristics highly independent of temperature, greatly simplifying biasing.
• Wider dynamic range than transistors circuits, due to higher operating voltages and overload tolerance.
• Device capacitances vary only slightly with signal voltages (Miller effect).
• Capacitive coupling can be done with small, high-quality film capacitors, due to inherently high-impedances of tube ciruits.
• Circuit designs tend to be simpler than transistorized equivalents, which are greatly complicated by the need to linearize intrinsically non-linear transistors.
• Operation is usually in Class A or Class AB, minimizing crossover notch distortion.
• Output transformer in power amp protects speaker from DC voltage due to malfunction and protects tubes from shorts and blunts back-emf spikes from speaker.
• Tubes can be relatively easily replaced by user.
  

Vacuum Tubes: Disadvantages

• Bulky, hence less suitable for portable products.
• Higher operating voltages generally required.
• High power consumption; needs heater supply that generates waste heat and yields lower efficiency, notably for small-signal circuits.
• Glass tubes are fragile, compared to metal transistors.
• Sometimes more prone to microphonics than transistors, depending upon circuit and device.
• Cathode electron-emitting materials are used up in operation.
• High-impedance devices that need impedance matching transformer for low-impedance loads, like speakers; however, the magnetic cushion provided by an output transformer prevents the output tubes from blowing up.
• Sometimes higher cost than equivalently powered transistors.
  

Transistors: Advantages

• Usually lower cost and smaller than tubes, especially in small-signal circuits.
• Can be combined in the millions on one cheap die to make an integrated circuit, whereas tubes are limited to at most three functional units per glass bulb.
• Lower power consumption, less waste heat, and high efficiency than equivalent tubes, especially in small-signal circuits.
• Can operate on lower-voltage supplies for greater safety, lower costs, tighter clearances.
• Matching transformers not required for low-impedance loads.
• Usually more physical ruggedness than tubes (depends upon construction).
  

Transistors: Disadvantages

• Tendency toward higher distortion than equivalent tubed circuits.
• Complex circuits and considerable negative feedback required for low distortion.
• Sharp clipping, in a manner widely considered non-musical, due to considerable negative feedback commonly used.  Does not gracefully roll-off or gently compress; instead, cuts off sharply, suddenly and abruptly with extremely hard edge.
• Device capacitances tend to vary wildly with applied voltages (Miller effect).
• Large unit-to-unit manufacturing tolerances and unreliable variations in key parameters, such as gain and threshold voltage.
• Stored-charge effects add signal delay, which complicates high-frequency and feedback design.
• Device parameters vary considerably with temperature, complicating biasing and increasing likelihood of thermal runaway, hotspots and unreproducible behavior.
• Cooling is less efficient than with tubes, because lower operating temperature is required for reliability.  Tubes prefer hot; transistors do not.  Massive, expensive and unwieldy heat sinks are always required for power transistors, yet they are not always effective (power output transistors still blow up; whereas, tubes fade down gracefully over time with warning and usually without catatrophic results).
• Power MOSFETs have high input capacitances that vary with voltage, complicating driver circuitry.
• Class B totem-pole circuits are common, which cause severe crossover distortion, or else necessitate huge amounts of negative feedback to correct.  This “measures well” for steady-state signals, but it completely “sucks the life out of” dynamic and transient signals such as music.
• Less tolerant of overloads and voltage spikes than tubes.  Except for their robust and forgiving heater filaments, it is very difficult, bordering on impossible, to blow out a tube with overvoltage; whereas, most transistors can be destroyed with as little as six volts, and every transistor can be destroyed by some voltage.  Tubes are much harder to “zap.”
• Nearly all transistor power amps have directly-coupled outputs that can damage speakers, even with active protection.
• Capacitive coupling usually requires high-value electrolytic capacitors, which give audibly and measurably inferior performance at audio frequency extremes.
• Greater tendency to pick up radio frequency interference and self-oscillate to the point of self-destruction, due to rectification by low-voltage diode junctions or slew-rate effects.
• Maintenance more difficult; devices are not easily replaced by user.
• Biasing more difficult, as temperature effects and device variations complicate circuitry and degrade performance.
• Older transistors and ICs often become unavailable after only 20 years, and sometimes much less, making replacement difficult or impossible.  Tubes have a staying power, proven over many decades.
• Hardly scientific or objective, but whereas transistors operate on an invisibly microscopic, quantum scale, tubes exist and operate on an intuitive, human scale.  You can see the heaters lit up, you can sometimes see a glowing plasma, and you can feel and hear the warmth.  Everything about tubes exists in a more human realm than hard, cold transistors.  Measure away, but it’s the sound that matters.
  

wangxy

Vacuum Tubes Versus Solid-State
The tube versus transistor debates that you hear most often occur in the pages of consumer and music magazines, with descriptive, but imprecise language like “warm”, “liquid”, “smooth”, and “dynamic”.
But what do the engineers who actually design the equipment think about tubes versus transistors in terms of objective science and measurements?
The two professional societies that have the most to say on this subject are the IEEE (Institute of Electrical and Electronics Engineers) and the AES (Audio Engineering Society). Both of these professional societies publish peer-reviewed journals, with articles written by engineers and scientists who work in the professional and consumer audio industry, as well as in cutting-edge academic research. If you are seeking a balanced view on this debate, direct yourself to either or both of these societies.
Below we point you to some readily available IEEE and AES publications that will help you better understand the differences between solid-state and vacuum tube electronics, their performance, and ultimately their sound.
IEEE - The Cool Sound of Tubes
The IEEE published “The Cool Sound of Tubes” in their August 1998 issue of IEEE Spectrum. In the same article, there is also a useful sidebar on tube versus transistor distortion. Finally, there is a useful table summarizing the advantages and disadvantages of tubes and transistors from both sonic and design points of view. Since the table is only available as a graphic image, we transcribe the text from the summary table below while highlighting some of the key points that directly impact sound quality:
Vacuum tubes – Advantages
Highly linear without negative feedback, specially some small-signal types
Clipping is smooth, which is widely considered more musical than transistors
Tolerant of overloads and voltage spikes
Characteristics highly independent of temperature, greatly simplifies biasing
Wider dynamic range than typical transistor circuits, thanks to higher operating voltages
Device capacitances vary only slightly with signal voltages
Capacitive coupling can be done with low-value, high-quality film capacitors
Circuit designs tend to be simpler than semiconductor equivalents
Operation is usually in Class A or AB, which minimizes crossover distortion
Output transformer in power amp protects speaker from tube failure
Maintenance tends to be easier because user can replace tubes
Vacuum tubes – Disadvantages
Bulky, hence less suitable for portable products
High operating voltages required
High power consumption, needs heater supply
Generate lots of waste heat
Lower power efficiency than transistors in small-signal circuits
Low-cost glass tubes are physically fragile
More prone to microphonics than semiconductors, especially in low-level stages
Cathode electron-emitting materials are used up in operation, resulting in shorter lifetimes (typically 1-5 years for power tubes)
High-impedance devices that usually need a matching transformer for low impedance loads, like speakers
Usually higher cost than equivalent transistors
Transistors – Advantages
Usually lower cost than tubes, especially in small-signal circuits
Smaller than equivalent tubes
Can be combined in one die to make integrated circuit
Lower power consumption than equivalent tubes, especially in small-signal circuits
Less waste heat than equivalent tubes
Can operate on low-voltage supplies, greater safety, lower component costs, smaller clearances
Matching transformers not required for low-impedance loads
Usually more physical ruggedness than tubes (depends on chassis construction)
Transistors – Disadvantages
Tendency toward higher distortion than equivalent tubes
Complex circuits and considerable negative feedback required for low distortion
Sharp clipping, in a manner widely considered non-musical, due to considerable negative feedback commonly used
Device capacitances tend to vary with applied voltages
Large unit-to-unit variations in key parameters, such as gain and threshold voltage
Stored-charge effects add signal delay, which complicates high-frequency and feedback amplifier design
Device parameters vary considerably with temperature, complicating biasing and raising the possibility of thermal runaway
Cooling is less efficient than with tubes, because lower operating temperature is required for reliability
Power MOSFETs have high input capacitances that very with voltage
Class B totem-pole circuits are common, which can result in crossover distortion
Less tolerant of overloads and voltage spikes than tubes
Nearly all transistor power amplifiers have directly-coupled outputs and can damage speakers, even with active protection
Capacitive coupling usually requires high-value electrolytic capacitors, which give inferior performance at audio-frequency extremes
Greater tendency to pick up radio frequency interference, due to rectification by low-voltage diode junctions or slew-rate effects
Maintenance more difficult; devices are not easily replaced by user
Older transistors and ICs often unavailable after 20 years, making replacement difficult or impossible
 
AES - Tubes versus Transistors: Is There An Audible Difference
The AES (Audio Engineering Society) published the a journal article in May 1973 titled "Tubes versus Transistors: Is There An Audible Difference" that focuses primarily on the distortion aspects of tubes versus transistors.
One of the more interesting quotes from the AES article:
“Our extensive checking has indicated only two areas where vacuum-tube circuitry makes a definite audible difference in the sound quality: microphone preamplifiers and power amplifiers driving speakers or disc cutters. Both are applications where there is a mechanical-electrical interface.”
In addition to speakers, disc cutters and microphones we can include phono cartridges and musical instrument pick-ups (ie. guitars) in the world of mechanical-electrical interfaces where tubes have an advantage.
For impatient readers, skip to the section titled DISTORTION CHARACTERISTICS OF PREAMPLIFIERS, as this section covers the more relevant aspects of tube versus transistor sound.
This AES article dispels the myth that tubes overload more gently than transistors. This conclusion is reached by comparing variations in the slopes of the distortion characteristics (THD) for silicon transistors, pentodes and triodes. The finding is that there is little variation in how the transistors and vacuum tubes overload. However, there is a difference when they overload. Specifically:
“Overloading an operational amplifier produces such steeply rising edge harmonics that they become objectionable within a 5-dB range. Transistors extend this overload range to about 10 dB and tubes widen it to 20 dB or more.”
In the tests conducted for the AES journal article:
“Further listening revealed that it was only in the range of early overload where the amplifiers differed appreciably in sound quality. Once the amplifiers were well into the distortion region, they all sounded alike -- distorted. In their normal non-overload range all three amplifiers [transistor, hybrid op-amp, and vacuum-tube triode] sounded very clean.”
and
“Engineering studios show that any amplifier adds distortion as soon as the overload point is reached. The tests show that all amplifiers could be overloaded to a certain degree without this distortion becoming noticeable. It may be concluded that these inaudible harmonics in the early overload condition might very well be causing the difference in sound coloration between tubes and transistors.”
The article then digs deeper into the perceived “sound” of the relative distortion harmonics of tubes versus transistors. It was found that:
“There is a close parallel here between electronic distortion and musical tone coloration that is the real key to why tubes and transistors sound different.”
Further reading explains in detail the effects that harmonics have on sound coloration:
" The primary color characteristic of an instrument is determined by the strength of the first few harmonics. … The odd harmonics (third and fifth) produce a "stopped" or "covered" sound. The even harmonics (second, fourth, and sixth) produce "choral" or "singing" sounds. The second and third harmonics are the most important from the viewpoint of the electronic distortion graphs in the previous section. Musically the second is an octave above the fundamental and is almost inaudible; yet it adds body to the sound, making it fuller. The third is termed quint or musical twelfth. It produces a sound many musicians refer to as "blanketed." Instead of making the tone fuller, a strong third actually gives the sound a metallic quality that gets annoying in character as its amplitude increases. A strong second with a strong third tends to open the "covered" effect. Adding the fourth and fifth to this changes the sound to an "open horn" like character. "
" The higher harmonics, above the seventh, give the tone "edge" or "bite." Provided the edge is balanced to the basic musical tone, it tends to reinforce the fundamental, giving the sound a sharp attack quality. Many of the edge harmonics are musically unrelated pitches such as the seventh, ninth, and eleventh. Therefore, too much edge can produce a raspy dissonant quality. Since the ear seems very sensitive to the edge harmonics, controlling their amplitude is of paramount importance."
The last section, RELATIONSHIP OF FACTORS AND FINDINGS, ties everything together. The final paragraph sums it up best:
“Vacuum-tube amplifiers differ from transistor and operational amplifiers because they can be operated in the overload region without adding objectionable distortion. The combination of the slow rising edge and the open harmonic structure of the overload characteristics form an almost ideal sound- recording compressor. Within the 15-20 dB "safe" overload range, the electrical output of the tube amplifier increases by only 2-4 dB, acting like a limiter. However, since the edge is increasing within this range, the subjective loudness remains uncompressed to the ear. This effect causes tube-amplified signals to have a high apparent level, which is not indicated on a volume indicator (VU meter). Tubes sound louder and have a better signal-to-noise ratio because of this extra subjective headroom that transistor amplifiers do not have. Tubes get punch from their naturally brassy overload characteristics. Since the loud signals can be recorded at higher levels, the softer signals are also louder, so they are not lost in tape hiss and they effectively give the tube sound greater clarity. The feeling of more bass response is directly related to the strong second and third harmonic components, which reinforce the "natural" bass with "synthetic" bass [5]. In the context of a limited dynamic range system like the phonograph, recordings made with vacuum-tube preamplifiers will have more apparent level and a greater signal to system noise ratio than recordings made with transistors or operational amplifiers.”
When playing back early 78 RPM (shellac) disc recordings through a tube phono stage like the Wavestream Kinetics Archival Phono Stage, you will notice a different dynamic character because of the above tube response and dynamics. Subtle artist intonations are clearer and more pronounced, fostering a greater sense of realism and emotional connection to the recording.

黑达可

你不介意翻译下的话我就不介意看一下。

comixxing

求翻译

xsox

楼主既然这么纠结，难到不知道还有胆石结合的耳放么？买一个不就不纠结了？

wangxy

xsox 发表于 2017-9-16 19:39
楼主既然这么纠结，难到不知道还有胆石结合的耳放么？买一个不就不纠结了？

正确。