It’s also a tonal choice – the doesn’t have a CF to drive the tone stack, and it has a pretty significant affect on the tone. Cathode Follower Vs Aikido Cathode Follower Unlike the grounded-cathode amplifier, whose PSRR improves by the replacement of the plate resistor with a constant-current source, the cathode follower’s PSRR worsens with the replacement of its cathode resistor by a constant-current source. In fact, I will quote from blog , Cathode-follower-based output stages are rareā€”surprisingly rare. The above assumes that we impose a grid voltage limit of 0V; in other words, no positive grid voltages. Furthermore, adding an interstage transformer to amplifier makes adding a global negative feedback loop at least difficult, if not dangerous, due to the phase shifts that a transformer would introduce. The output tube receives its input signal from the input tube and no capacitor connects the output tube’s cathode to the input stage. Inverted Triadtron Speaking of hybrid Triadtron circuits, we can use the same Triadtron Vbe reflecting trick to create a voltage amplifier, rather than a unity-gain buffer.

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Or we might try something along the following lines: These power supplies ensure that the pentode’s screens are tightly locked to the swinging cathodes and they also directly connect to the driver stages plate resistors, which undoes all the cathode follower attributes, as the bootstrapping relays any disturbance at the output cathodes right back to the output grind in phase, not anti-phase. And there is energy beyond that, and it’s not falling very much. Vertical and horizontal grids.


Wed Jul 13, 9: Two power supplies are required: Wavac operates the tube at a very low plate voltage of around 8.

Neither a pentode nor a Cathode Follower Be

However small changes in bias and resistors bring THD up to merely “point”, and typical designs are lucky to do so well unless level and load are trivial. I’m sure you could charge double and still have happy customers.

The actors and set have changed, but it’s the same play. Previous 1 2 Next. As expected, with a current source and no loading a single triode is damn near perfectly distortion free.

The ACF use is not limited to line-stages, as the ACF can be used in creating an active crossover or even a headphone driver, if the headphone’s impedance is high enough. The output tube functions as a pentode, not a triode.

However, the damping factor of the amplifier was rather low. Safety is always a consideration, especially with kits where the manufacturer has no control over how the final product is assembled.

When the bottom triode lets go, reducing its current flow in other words, cathodf cathode falls in voltage, as its cathode resistor pulls down. As the input tube conducts more current, the voltage drop across resistor Rs grows in voltage, which then lowers the slave triode’s the right triode’s current flow. Vmware Converter 5 Performance. We have developed a couple solutions, vollower are using them in an increasing number of products.

But really, at the heart of it, I don’t understand the mechanism that would make a CF sound bad at cathod. I’m sure you could charge double and still have happy customers. Simulated THD can be point-oh-oh, and this does not rise for loads down to zero.


For DC supplies, we have taken several steps to eliminate sources of noise and sonic roughness. Moreover we need the extra heater windings, as the output tube’s heater should attach to a floating heater winding referenced to its cathode, as the cathode will swing hundreds of volt up and down from ground.

Amp Chokes, Cathode Followers, and other Maplifier Questions

This wasn’t a first, as I have covered the topic many times before; see blog andfor example. This choice was inspired by ctahode high current demands that I needed.

Stereo and mono, octal and 9-pin printed circuit boards available. The resistor and capacitor offer an added advantage in that the RC-filter action they impose improves the PSRR of the output tube.

Well see how that sounds before I put up a flllower. The small modulation of input capacitance with swing will degrade things some with nonzero source Z. A cathode follower sitting on top of a choke?

An accordion single-ended power amplifier can be made with both output tubes functioning as cathode follower; see the PDF for details.

W out of the amplifier. The full schematic phase 1 The schematic reveals a fairly simple topology. Now, the top triode is cutoff and the bottom triode is fully on.