Building a tube amplifier is a dream for many engineers and manufacturers alike. But factors like cost, bulky housing, transformers, and complex wiring harnesses can scare even the most ambitious people away. In 2014, Michiel Ter Burg developed his solution for a compact tube amplifier. please look.
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vacuum tube amplifier circuit
See tube amplifier circuit diagram. Ter Burg explains: “The audio input signal on connector K1 is fed to the input transformer TR2. The secondary of this transformer drives his two triode sections of the vacuum tube in antiphase through resistors R8 and R12.”
The anodes of the pentode sections of vacuum tubes V1 and V2 are connected to the primary winding of transformer TR1 (Encapsulated PCB Mount Power Transformer), which is here reconstituted as an output transformer. The output signal from the triode is fed to the pentode control grid via networks C3/R3 and C5/R16. The two secondary windings of TR1 drive the loudspeaker.” See this article for circuit details please.
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Printed board
See Single Amplifier Channel PCB Layout. In the case of a stereo amplifier, it is necessary to assemble two units. Ter Burg says: “After assembling the amplifier board and power supply, you can warm up the tubes for a while and then adjust the quiescent current and balance. As already mentioned, start with a quiescent current of 25 mA per tube (250 mV on the K5), You can adjust the balance so that they draw exactly the same current. Now you're ready to start listening to your amp.”
“The author obtained the best results by connecting the two output windings in parallel and connecting a 4.7 kΩ resistor in the feedback path as shown in the schematic. or panel type, regardless of impedance), the sound is similar to what you'd expect from a tube amp, including great detail in the bass and smooth overdrive at high signal levels.Measured at full power, The bandwidth may be a little disappointing, but in real-world listening situations, the bandwidth is so wide that you won't miss anything. It gets pretty loud at low output levels, extending to over 10 kHz.”
Learn more about tube amps
An article related to this tube amp project was published in Elektor January/February 2014. Elektor members have full access to Elektor's library, including this article.
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