The Counterpoise has no air gap, unlike all other single-ended transformers. How is this possible? The Counterpoise incorporates a proprietary core degaussing coil that neutralizes the DC-induced magnetic field that would otherwise saturate the core and lead to distortion. The thematic diagram to the right shows the basic design of a Counterpoise.
The Counterpoise offers many advantages over traditional single-ended output transformers.
The Varipoise offers many advantages over traditional push-pull output transformers.
Typical Features and Specifications:
Our CNC machine has easy-to-use but versatile software to drive the machine to make precision components that can hold tolerances of better than 1/1000-inch, even in wood. The machine itself is built in the USA using materials and components primarily sourced from USA suppliers.
The easy programmability of the CNC machine allows us to quickly customize each product we make. This CNC machine is one of the secrets to our unique ability to produce one-of-a-kind custom products individually, yet achieve the same efficiency as other boutique equipment makers who produce only a few largely-standardized models. We can achieve this efficiency without compromise, in part thanks to our CNC machine.
KVG Laboratories does build most of its electronics products with vacuum tubes because we can create any sound the customer requires more quickly and more easily with tubes than we could with transistors. Regardless of whether the customer wants extreme clarity, extreme distortion or anything in-between, KVG Laboratories can almost always satisfy the required sound using vacuum tubes. In those instances where portability or size are important requirements, or where we cannot satisfy sound requirements with vacuum tubes, we use a variety of transistor designs.
Engineers and musicians have long debated the question of tube sound compared to transistor sound. Measurements of the differences assume the tested amplifiers operate perfectly linearly, which in fact is never the case. Conventional methods of frequency response, distortion and noise usually show that no significant difference exists between tubes and transistors. Recording engineers often are directly involved with the controversy of tube sound versus transistor sound, especially in pop recording and in audiophile recording projects. Differences are quite noticeable now that solid-state consoles are commonplace. It's not uncommon during a recording session in studios notorious for bad sound that a visiting engineer will plug the microphones into vacuum tube mixers or preamplifiers instead of the regular console. The result is often a change in sound quality that is nothing short of incredible, surpassing even improvements made to the studio's acoustics.
Those who avidly listen to analog LP disc records can easily discern that tubes sound different from transistors. Defining the cause of the difference is a complex problem in psychoacoustics, that is further complicated by a wide variety of subtle phenomena. Musicians usually are more objective listeners than audiophiles or engineers. They don't express their observations in standard units, but the musician's "by ear" measuring technique seems quite valid because the human ear's response may be quite different than an oscilloscope's.
Common statements by musicians express their observations that:
The major distortion characteristics of vacuum tube amplifiers are the presence of strong second and third harmonics, often in concert with, but greater than, the amplitudes of the fourth and fifth. Harmonics above the fifth harmonic are insignificant until the equipment's overload exceeds 12 deciBels.
At first, the vacuum tube was the only way to build audio equipment. The 1950s brought the transistor, which rapidly pushed vacuum tube-based electronics out of the market because advertisers in the late 1960s said that the solid-state electronics was the “wave of the future,” claiming it was always quieter, clearer and more accurate when compared to vacuum tube gear. That told only part of the story. Transistors are the best technology for many applications (computers being one excellent example), but they are not always the best way to build an audio circuit. Professional recording studios and many audiophiles have always prized tubes for the tone and quality of the sound they produce, seeking the very “coloration” that was criticized in Hi-Fi marketing literature. The recent rise of computer-based digital audio has increased the demand for tubes.
Triodes and pentodes differ in the composition of their distortion components. When triode tube amplifiers distort, the second harmonic is dominant, followed closely by the third harmonic; the fourth harmonic's level rises 3 to 4 deciBels later; and the fifth, sixth, and seventh harmonics remain below 5% up to the equipment's 12 deciBel overload point. Clipping is asymmetrical and the waveform's duty cycle shifts prominently. When pentode and cascode amplifiers distort, the third harmonic is dominant and the second harmonic increases about 3 dB later, both the fourth and the fifth harmonics are prominent, the sixth and seventh harmonics remain under 5% up to the equipment's 12 dB overload point. Clipping is asymmetrical and the waveform's duty cycle shifts slightly.
Transistor electronics have different distortion characteristics, with their distortion being dominated almost entirely by the third harmonic, with all other harmonics present at a much lower amplitude than the third harmonic. As transistor electronics overload, the amplitudes of all the higher harmonics begin to increase simultaneously within 3 to 6 deciBels of the 1% third harmonic point. Overload waveforms of transistor amplifiers are the distinct square wave shapes, Clipping is symmetrical and the waveform's duty cycle is not altered.
Operational-amplifier, or opamp, electronics exhibit distortion similar to that of transistor electronics, of course, but the rate of the increase in the slope of distortion rises steeply because of the extreme amount of inverse feedback inherent to opamp-based circuits. The third harmonic is the dominant distortion component, but its slope increases steeply, occurring from Also rising very strongly from the same point as origin of the fifth and seventh harmonics. Opamps suppress all even-order harmonics completely. Even slight overloading results in a perfect square wave, limiting the opamp circuit's ability to reproduce transient overload cleanly.
In summary, the differences between tube and transistor sound is caused by the relative proportions of the harmonics that comprise the amplifier's distortion during the time the amplifier overloads. Transistor amplifier distortion is mainly comprised of the third harmonic, creating a "veiled" sound that gives recordings a restricted quality. When a vacuum tube amplifier overloads it generates a spectrum of harmonics comprised of a particularly strong second harmonic, with overtones from the third harmonic, fourth harmonic, and fifth harmonic, creating a full-bodied "brassy" quality to the sound. As the amplifier's overload increases, the magnitude of the seventh harmonic, eighth harmonic, and ninth harmonic greatly increase, adding an edginess to the sound which the human ear interprets and a sign of increasing loudness. When an opamp overloads, it produces harmonics with such extremely-fast rising slopes that they quickly become objectionable. Transistors extend the overload range, while vacuum tubes provide the greatest extension of overload range. This illustrates why vacuum tube amplifiers are considered excellent for music instrument amplifiers as well as high-end high fidelity amplifiers.
Musicians have determined how various harmonics relate to the timbre of a musical instrument.
As an aside, the second and third harmonics are those used when making electronic distortion measurements, which brings into question the validity of steady-state distortion measurements as a means of predicting the subjective quality of an amplifier.