Audio Engineering

342 Chapter 11 anode current resistance of the valve, Ra , is also related to the anode/cathode spacing and becomes higher as th ...

Valve (Tube-Based) Amplifi ers 343 presence becomes of particular importance when a negatively charged control grid is introduce ...

344 Chapter 11 capacitance, typically of the order of 2.5 pF, between the grid and the anode. In itself, this latter capacitance ...

Valve (Tube-Based) Amplifi ers 345 In use, a small-signal pentode amplifying stage will give a much higher stage gain than a med ...

346 Chapter 11 Both pentodes and beam tetrodes can be used with their screen grids connected to their anodes. In this mode their ...

Valve (Tube-Based) Amplifi ers 347 evolution from the cathode, or any other electrodes that may become hot in use. The solution ...

348 Chapter 11 exceed 200 V. Moreover, there must always be a resistive path, not exceeding 250 k Ω , between the cathode and he ...

Valve (Tube-Based) Amplifi ers 349 taken in the manufacture of valves to maintain the fi rmness of the mounting of the grids and ...

350 Chapter 11 is inconvenient in use. Also, it does not lend itself at all well to contemporary mass- production techniques. In ...

Valve (Tube-Based) Amplifi ers 351 audio frequency transformer. This is a diffi cult component to incorporate within a high- fi ...

352 Chapter 11 The primary:secondary turns ratio of this component would need to be  (10 k/3)  58:1. It is diffi cult to desig ...

Valve (Tube-Based) Amplifi ers 353 either open-circuit (O/C) or short-circuit (S/C), but with some internal resistance, shown as ...

354 Chapter 11 i VV (^1) R 1 2   x (11.3) and i x V (^3) R 3  (11.4) from Equations (11.1), (11.2), and (11.3) we have i VV R ...

Valve (Tube-Based) Amplifi ers 355 11.5 Phase Splitters ........................................................................ ...

356 Chapter 11 Some local negative feedback from anodes to grids in V 2 and V 3 is applied by way ofC 4 / R 4 and C 6 / R 7 in a ...

Valve (Tube-Based) Amplifi ers 357 arrangement, because this simply adds just another increment of waveform distortion, due toV ...

358 Chapter 11 phase-splitter circuits, it has the disadvantage that the available AC output swing, at either anode, is reduced ...

Valve (Tube-Based) Amplifi ers 359 type of construction will lead to the almost complete stripping of the space charge from the ...

360 Chapter 11 The required grid drive voltage for typical pentode or beam tetrode output valves, at Va  300 V, will be in the ...

Valve (Tube-Based) Amplifi ers 361 much in the way of exotic components, circuit complexity, or very high-quality output impedan ...