Specifications

On the tube Tweak GUI, the editable parameters are divided into two groups, the Physical and the Non-

Physical (which has no mean ing in reality but can be used to enhance the sonic properties).

Depending on which tube you wish to tweak, you can choose between triodes or pentodes. A power pentode

is a tube type often used to drive the speakers, therefore you will usually nd them as the last tube(s) in the

chain of any amplier. Triodes are voltage (V) ampliers, whereas power pentodes (combined with a

transformer) in ReValver

™

MK III.V are treated as current (I) generators. You can replace any tube in the module

with another tube of the same general type, from a stock of templates. The internal parameters of a tube

consist of features like amplica tion, linearity and driving strength. These parameters cannot be changed and

are not displayed on the GUI. If you check the option Only Load Internals, only these parameters will be

loaded, otherwise the entire GUI will be reset. The Character parameter can be used to shape the frequencies

of the distorted component. (On low input, the Character has minimal impact on the sound.)

If you are editing a pentode you have the option of conguring it as a single-ended amplier or as a push-

pull amp. One push-pull tube is actually an even-number 2 or 4, but as the parameters are identical for all, only

one tube icon is displayed on the Tweak GUI. A tri ode can only be congured as a plate follower (a cathode-

biased voltage gain stage).

VPP is the power supply voltage delivered to the tube stage from the power supply. Usually, the VPP is slightly

lower if the stage is located early in the signal chain. In case the power supply is “sag ging” (usually due to

heavy load and high volumes), the VPP becomes temporarily lower, but the amount depends on internal

values in each ReValver MK III.V amp module.

Plate load (triode) and transformer impedance (pentode) are the parameters over which the signal is

generated. The value of the load aects the signal output strength. Also, the transfer characteristics of the load

changes the voltage on, and current through, the tube itself.

Attenuation is not directly a part of the tube stage but can be thought of as a generic way of decreasing

(attenuating) the signal after amplication.

Cathode resistor (where applicable) is a resistor which is used to bias the tube, or in other words balance the

symmetry of the waveform. It is commonly set near 1.5 kOhms for triodes, but the actual setting depends on

the desired sound. The setting will also aect the overall gain in an “unbypassed” stage. (See denition of

“unbypassed” below.)

Cathode capacitor (where applicable) is connected in parallel with the cathode resistor. It has two main

eects on sound: 1) The capacitor enables the stage to amplify the signal more; and 2) It will act as a low-shelf

lter, eectively cutting out some low bass. The cuto frequency is equal to 1/(6.28*RC), with C as the

capacitor value and R as the value of the cathode resistor. This in turn aects the distortion spectrum. With a

cathode capacitor, the stage is called bypassed, and without, unbypassed.