THD BiValve Boutique Tube Amp

The THD BiValve-30 30W Class A Amplifier Head is a pure Class A design with 2 output tubes wired in parallel and combined through a special output transformer to deliver up to 30W. It accepts almost any type of output or preamp tube without bias adjustment-even in combination-for an astonishingly wide range of tone available for nearly any style of guitar playing. The standard of construction is absolutely top class, as you would expect for any handmade amplifier.Underneath its large, perforated steel lid you'll find large transformers and hi-fi style internal baffle plates to cut down on hum, as well as the tube sockets. On its front panel is a pair of input jacks labeled More and Less, followed by a Cut switch (high-cut filter), Volume, Treble, Bass, and Attitude (driver tube response control). In the center is a light bulb that glows as the amp distorts with a small switch to turn it off, a control for the built-in Hot Plate (output attenuator), and a defeat switch for the Hot Plate.The amp sports an acid-etched control plate with a delicate marine theme inspired by Glasgow artist Charles Rennie Mackintosh.

Like the UniValve, the THD BiValve Rack-mounted Guitar Amp Head is a single-ended pure Class A design. However, it has two output valves that are wired in parallel and combined through a special output transformer to deliver up to around 30 watts. You can use almost any output valve you like without touching any kind of bias adjustment, and get this: in the BiValve you can use them in any combination as well. Combined with the capability to take almost any preamp valve, this makes the BiValve even more of an amp-tweaker's dream than its predecessor. Because there's such a wide range of tone available, you create your own style.The BiValve Rack mount amplifier head sits in the same compact pressed steel chassis as the UniValve and, except for the extra valve and control plate, it looks almost identical. Glasgow artist Charles Rennie Mackintosh inspired the UniValve's acid-etched control plate; this time round THD have gone for a marine theme, with an intricate diamond scale design. The control markings are screen printed, which makes them easier to see.Underneath the perforated steel lid there's a larger pair of transformers to handle the increased output, and inside there are two ultra-thick PCBs: one for the power supply and one for the audio. The four valve bases are bolted to the chassis and secured by locking nuts, with hi-fi style internal baffle plates to cut down on radiated hum. The standard of construction is absolutely top class. THD are based in Seattle, which is also hometown to Boeing, and most of the BiValve's heavy fabrication work is contracted out to local specialist companies who service the aircraft industry.The front panel looks deceptively simple. Working from the left, there's a pair of input jacks labeled "more" and "less", followed by a treble cut switch then rotary controls for volume, treble, bass and what THD call "Attitude". It's not a fancy name for a presence control - there'

Like the UniValve, the THD BiValve Rack-mounted Guitar Amp Head is a single-ended pure Class A design. However, it has two output valves that are wired in parallel and combined through a special output transformer to deliver up to around 30 watts. You can use almost any output valve you like without touching any kind of bias adjustment, and get this: in the BiValve you can use them in any combination as well. Combined with the capability to take almost any preamp valve, this makes the BiValve even more of an amp-tweaker's dream than its predecessor. Because there's such a wide range of tone available, you create your own style.The BiValve Rack mount amplifier head sits in the same compact pressed steel chassis as the UniValve and, except for the extra valve and control plate, it looks almost identical. Glasgow artist Charles Rennie Mackintosh inspired the UniValve's acid-etched control plate; this time round THD have gone for a marine theme, with an intricate diamond scale design. The control markings are screen printed, which makes them easier to see.Underneath the perforated steel lid there's a larger pair of transformers to handle the increased output, and inside there are two ultra-thick PCBs: one for the power supply and one for the audio. The four valve bases are bolted to the chassis and secured by locking nuts, with hi-fi style internal baffle plates to cut down on radiated hum. The standard of construction is absolutely top class. THD are based in Seattle, which is also hometown to Boeing, and most of the BiValve's heavy fabrication work is contracted out to local specialist companies who service the aircraft industry.The front panel looks deceptively simple. Working from the left, there's a pair of input jacks labeled "more" and "less", followed by a treble cut switch then rotary controls for volume, treble, bass and what THD call "Attitude". It's not a fancy name for a presence control - there'

Like the UniValve, the THD BiValve Rack-mounted Guitar Amp Head is a single-ended pure Class A design. However, it has two output valves that are wired in parallel and combined through a special output transformer to deliver up to around 30 watts. You can use almost any output valve you like without touching any kind of bias adjustment, and get this: in the BiValve you can use them in any combination as well. Combined with the capability to take almost any preamp valve, this makes the BiValve even more of an amp-tweaker's dream than its predecessor. Because there's such a wide range of tone available, you create your own style.The BiValve Rack mount amplifier head sits in the same compact pressed steel chassis as the UniValve and, except for the extra valve and control plate, it looks almost identical. Glasgow artist Charles Rennie Mackintosh inspired the UniValve's acid-etched control plate; this time round THD have gone for a marine theme, with an intricate diamond scale design. The control markings are screen printed, which makes them easier to see.Underneath the perforated steel lid there's a larger pair of transformers to handle the increased output, and inside there are two ultra-thick PCBs: one for the power supply and one for the audio. The four valve bases are bolted to the chassis and secured by locking nuts, with hi-fi style internal baffle plates to cut down on radiated hum. The standard of construction is absolutely top class. THD are based in Seattle, which is also hometown to Boeing, and most of the BiValve's heavy fabrication work is contracted out to local specialist companies who service the aircraft industry.The front panel looks deceptively simple. Working from the left, there's a pair of input jacks labeled "more" and "less", followed by a treble cut switch then rotary controls for volume, treble, bass and what THD call "Attitude". It's not a fancy name for a presence control - there'

This THD amp is a 30W, 1x12 combo version of the THD BiValve-30 Class A Amplifier Head which has 2 output tubes wired in parallel and combined through a special output transformer to deliver up to 30W. It accepts almost any type of output or preamp tube without bias adjustment—even in combination—for an astonishingly wide range of tone available for nearly any style of guitar playing. The amplifier's construction is absolutely top class, as you would expect for any handmade amplifier.Underneath its large, perforated steel lid you'll find large transformers and hi-fi style internal baffle plates to cut down on hum, as well as the tube sockets. On its front panel is a pair of input jacks labeled More and Less, followed by a Cut switch (high-cut filter), Volume, Treble, Bass, and Attitude (driver tube response control). In the center is a light bulb that glows as the amp distorts with a small switch to turn it off, a control for the THD BiValve-30's built-in Hot Plate (output attenuator), and a defeat switch for the Hot Plate.The THD BiValve-30 amp sports an acid-etched control plate with a delicate marine theme inspired by Glasgow artist Charles Rennie Mackintosh.

YJUNITriode Yellow JacketHow do they work?They give you simple Class-A operation from any amp.Yellow Jacket Converters not only rearrange the pin locations of the tubes, but also provide the necessary current limiting on the screens and cathode as well as blocking the amplifier's grid bias voltage, while configuring the EL84 in a Class-A, Self-adjusiting cathode-bias circuit. In other words, there are no adjustments to make and no modifications necesary, you simply plug the Yellow Jackets into the amp's output tube sockets, (in cathode-bias amplifiers) screw the ground wires under one of the output tube socket mounting screws, plug the provided EL84's into the Yellow Jackets, turn on the amp and play. How will they change my amplifier?It's like getting a whole new amplifier! In Champ and Deluxe type amplifiers, the Yellow Jackets output is smooth, strong and more even than with the stock 6V6s. When the Yellow jackets Converters are installed inlarger amplifiers intended for 6L6s or EL34 output tubes, the high plate and screen voltages are reduced as well as current limited to protect the EL84 and to drop output power. When a pair of Yellow Jackets are used in a Marshall 50 watt or similar amplifier, the overall power drops to about 20 watts and takes on more of the character of an old Vox AC30. The distortion is smoother and more even and the output is both substantially reduced and more compressed due to the Class-A nature of the Yellow Jackets. In a 100 watt amp like a Twin Reverb or Marshall 100, either two or four Yellow Jackets can be used. If only two are used and the other two sockets are left empy, the output is dropped to about 20 watts. With four in place, the amp puts out about 40 watts and takes on a whole new warmth and richness. In the cases of the YJ7591 converters, the overall ouput power remains the same, but the sound becomes fuller and the extinct 7591 are replaced with common and inexpensive EL84 tubes. In old Ampeg Reverb Rockets and the like, y

Like the UniValve, the THD BiValve Rack-mounted Guitar Amp Head is a single-ended pure Class A design. However, it has two output valves that are wired in parallel and combined through a special output transformer to deliver up to around 30 watts. You can use almost any output valve you like without touching any kind of bias adjustment, and get this: in the BiValve you can use them in any combination as well. Combined with the capability to take almost any preamp valve, this makes the BiValve even more of an amp-tweaker's dream than its predecessor. Because there's such a wide range of tone available, you create your own style.The BiValve Rack mount amplifier head sits in the same compact pressed steel chassis as the UniValve and, except for the extra valve and control plate, it looks almost identical. Glasgow artist Charles Rennie Mackintosh inspired the UniValve's acid-etched control plate; this time round THD have gone for a marine theme, with an intricate diamond scale design. The control markings are screen printed, which makes them easier to see.Underneath the perforated steel lid there's a larger pair of transformers to handle the increased output, and inside there are two ultra-thick PCBs: one for the power supply and one for the audio. The four valve bases are bolted to the chassis and secured by locking nuts, with hi-fi style internal baffle plates to cut down on radiated hum. The standard of construction is absolutely top class. THD are based in Seattle, which is also hometown to Boeing, and most of the BiValve's heavy fabrication work is contracted out to local specialist companies who service the aircraft industry.The front panel looks deceptively simple. Working from the left, there's a pair of input jacks labeled "more" and "less", followed by a treble cut switch then rotary controls for volume, treble, bass and what THD call "Attitude". It's not a fancy name for a presence control - there'

Like the UniValve, the THD BiValve Rack-mounted Guitar Amp Head is a single-ended pure Class A design. However, it has two output valves that are wired in parallel and combined through a special output transformer to deliver up to around 30 watts. You can use almost any output valve you like without touching any kind of bias adjustment, and get this: in the BiValve you can use them in any combination as well. Combined with the capability to take almost any preamp valve, this makes the BiValve even more of an amp-tweaker's dream than its predecessor. Because there's such a wide range of tone available, you create your own style.The BiValve Rack mount amplifier head sits in the same compact pressed steel chassis as the UniValve and, except for the extra valve and control plate, it looks almost identical. Glasgow artist Charles Rennie Mackintosh inspired the UniValve's acid-etched control plate; this time round THD have gone for a marine theme, with an intricate diamond scale design. The control markings are screen printed, which makes them easier to see.Underneath the perforated steel lid there's a larger pair of transformers to handle the increased output, and inside there are two ultra-thick PCBs: one for the power supply and one for the audio. The four valve bases are bolted to the chassis and secured by locking nuts, with hi-fi style internal baffle plates to cut down on radiated hum. The standard of construction is absolutely top class. THD are based in Seattle, which is also hometown to Boeing, and most of the BiValve's heavy fabrication work is contracted out to local specialist companies who service the aircraft industry.The front panel looks deceptively simple. Working from the left, there's a pair of input jacks labeled "more" and "less", followed by a treble cut switch then rotary controls for volume, treble, bass and what THD call "Attitude". It's not a fancy name for a presence control - there'