While an INA is often shown schematically like a standard op-amp, it is usually composed of three op-amps: one to buffer each input, one to provide the output, and one to support impedance matching ...

The Dynaco ST-70 was the company’s first stereo amplifier. It utilized four EL34 output tubes, one GZ34/5AR4 rectifier ... “By replacing the board you essentially change the entire circuit design, and ...

LTSPICE schematic of the K2-W Analog Computer Op Amp’s first stage. On the left half of my LTSPICE capture of the K2-W’s input stage schematic, the two cathodes are connected, which should be ...

Refer to the tube amplifier schematic. As Ter Burg explains, “The audio input signal on connector K1 is fed to input transformer TR2. The secondary of this transformer drives the two triode sections ...

This Swiss Army knife of an integrated amplifier produces remarkable sound in a design that combines Bluetooth streaming with a sophisticated phono stage. It implements unique circuit topology ...

Each circuit is simple enough, but to replicate it across all the lines in a breadboard makes for a huge amount of quad op-amp chips stuffed onto one piece of stripboard as well as a veritable ...

Silver Luna Prestige is an extremely versatile push-pull stereo integrated tube amplifier. Output tubes are the legendary EL34, and a mode switch can choose either tetrode or pentode operation; the ...

Figure 3 Output spectrum of the optocoupler circuit in Figure 2 with an input signal of 200 mV RMS. As one can see, the second harmonic of a 5 to 15 W tube amplifier dominates the spectrum, and EL34 ...

Changing valves affects the sonic signature of the amplifier, so it’s possible to fine-tune the CS600X’s sound to your tastes. There’s a pair of internal toggle switches that change the circuit ...

The current rage of lower power guitar amps is greatly enhanced with the addition of the hand-wired Park Little Head 18. It features the same pre-amp circuit as the Park 45. But there is now a highly ...