KVG Laboratories audio transformers use a proprietary M6 steel and nickel core in our output transformers that have high permeability and low distortion. Core composition begins with a basal steel core lamination made with M-6 29 Gauge - 0.014" (0.355 mm) Grain Orientated Electrical Transformer Steel Lamination, that is RoHS compliant. Our squared hysteresis loop iron-silicon alloy provides reduced core losses because of its higher permeability in the rolling direction, and are supplied in a stress relief annealed condition. The elementary patterns of the crystals in the material are oriented with the axis of easiest magnetization parallel with, and aligned in, the direction of rolling. Alignment is accomplished by special cold-rolling and annealing processes to allow our transformers to withstand more severe vibration and shock; exhibit lower core losses, higher initial permeability and higher permeability at increased induction magnitudes. Our transformers have a very stable VA/Temperature relationship over a wide range of ambient and operating temperatures. Note that our transformer laminations are tested under standards set up by the ASTM A-346.
Note that saturation induction is an important parameter of a transformer and is a principal means of manipulating the tone of a finished amplifier. Saturation induction decreases with increasing alloy content, which is why we specify alloy grade M6, which exhibits saturation induction levels of 2.03 Tesla, among the lowest levels possible with modern metallurgy.
Careful attention is paid to core lamination stacking factors, which is the ratio of the actual volume of steel in a stack, not including air or insulating materials, compared to the measured dimension of the stack. Laminations are coated with close attention to providing optimum inter-laminar resistance for reduction of stray flux losses. Coating resistance depends on both the thickness of the coating and its chemical composition. Better performance coatings are required for higher field strength applications or where elevated temperatures or higher efficiencies is required. C-2 and C-5 coatings are more difficult to weld consistently because of their higher surface resistance and coating thickness variations. Therefore, control ground current paths, particularly through the edges of the lamination, are carefully monitored when welding laminations with these coatings.
The steel that KVG Laboratories transformers use has a steam blue oxide on the surfaces and edges as an insulating medium to minimize stray losses between laminations. Steam blue oxide reduces rust and corrosion, and is compatible with a variety of welding processes and secondary powder, epoxy or E-coat processes.
Although bobbins made of Nylon 6/6 is the usual choice for most audio transformers, KVG Laboratories has taken this a step further to attain a class B 130-degree UL temperature classification. Therefore, all of KVG Laboratories's transformer bobbins are Glass Filled Nylon 6/6.
The magnet wire used in KVG Laboratories transformers is a Class 155 copper magnet wire, with an improved polyurethane film, over-coated with nylon, having a round cross section. The wire is RoHS compliant.
KVG Laboratories is pleased to announce our new Counterpoise Single-Ended Output Transformer, the product of ten year's intensive research into the design and quality of single-ended amplifiers. The Counterpoise is be standard equipment in many of our models. Typical single-ended transformers have an core made with an air gap to prevent the core from becoming saturated because of the unbalanced current flowing through the transformer primary windings. While many manufacturers boast of the design and materials used in their transformer core's air gaps, they nevertheless do have an air gap.
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.
- Variable voicing: can be adjusted to sound very clean with late distortion, or very dirty with early distortion, all at the twist of a knob This unique feature offers unparalleled tonal variation in music instrument amplifiers, or optimized performance in audiophile amplifiers.
- The Counterpoise eliminates the air gap found in all other single-ended transformers.
- A Counterpoise transformer is more compact than traditional designs.
- A Counterpoise transformer is less expensive than traditional designs.
- The bass response of a Counterpoise transformer is superior to traditional designs because the degaussing coil reduces core saturation, allowing the Counterpoise to handle greater magnetic flux densities than traditional designs.
- A Counterpoise transformer can be made in power levels up to 200-Watts or greater. High power output capability is practical with the Counterpoise, whereas traditional designs seldom are capable of more than 20 Watts or so.
The Varipoise offers many advantages over traditional push-pull output transformers.
- Variable voicing: can be adjusted to sound very clean with late distortion, or very dirty with early distortion, all at the twist of a knob. This unique feature offers unparalleled tonal variation in music instrument amplifiers, or optimized performance in audiophile amplifiers.
- The Varipoise is more reliable than most other push-pull transformers.
- The Varipoise transformer sounds great even with severely unbalanced output valves -- if one output tube fails, the amplifier will still make excellent sound with reduced output power. Your amplifier will be more reliable as a result.
- A Varipoise transformer lets the designer create new amplifier tones and unique-sounding guitar amplifiers.
- Amplifiers made with Varipoise transformers can operate in a balanced push-pull mode, a single-ended mode, a reverse-phase single-ended mode, or a continuously-variable unbalanced push-pull mode. This gives you a nearly-infinite variety of unusual tones and a sound like no other guitarist has.
Designed as the basis for a many of our products, our A8500, A8700, A8800 and A8900 Discrete Audio Opamps offer the clarity and musicality of traditional transistor circuitry with the high common-mode rejection and easy versatility of integrated circuit opamps. Moroever, our Discrete Audio Opamps are optimized for a specific purpose in ways no integrated circuit can. Discrete opamps such as the Opamp Labs 425 and the John Hardy 990 have been the secret behind many of the finest-sounding audio equipment. Building on this tradition, our discrete opamps are made with silicon, point contact or germanium bipolar transistors, Darlington transistors, FETs, MOSFETs or IGBTs for a nearly unlimited palette of sounds.
Typical Features and Specifications:
- Gain Product Badwidth of 3 MHz to 3.5 MHz.
- Wide dynamic range.
- Low noise floor - Equivalent Input Noise of better than -125 dB at 50 dB of gain.
- Wide frequency response, at least DC - 100 kHz +/- 0.1 dB at 50 dB of gain.
- Excellent transient response with minimum overshoot thanks to flexible compensation ports.
- Versatile, easy to implement; design as with any monolithic opamp.
- High reliability because they may be repaired in the field. Unlike IC opamps, damaged Discrete Audio Opamps don't need to be thrown away.
- Designed for several standard power supply voltages: +/-1.5V, +/-5V, +/-9V, +/-18V, +/-24V, and +/-36V,
An important part of our production facility is a small footprint CNC (computer numerically controlled) gantry mill designed for industrial cutting in wood, acrylic and metas. CNC machines are powerful tools controlled from a computer software program which enable the operator to make everything from simple cut-out shapes to intricate 3D carvings, and everything in between.
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.