An audio-transformer is seldom used as the...

Question 1 / 27070YJjifKO5D85UjXLkgHr5

Question 1 of 27070YJjifKO5D85UjXLkgHr5

An audio-transformer is seldom used as the output device in the plate circuit of a tetrode audio-amplifier stage:

Question 1 of 27070

An audio-transformer is seldom used as the output device in the plate circuit of a tetrode audio-amplifier stage:

🔍 Key Concepts

• Impedance matching between the tetrode plate circuit and the load (speaker or following stage) • How a tetrode’s plate impedance compares with the impedance that an audio transformer normally presents • What happens in a tube amplifier when the load impedance is too high or too low

💭 Think About

• Think about what the plate of a tetrode ‘wants to see’ as a load. Should that be a very high impedance, a very low impedance, or something in between for efficient power transfer? • If you used an ordinary audio transformer as the output device, how would that affect power transfer and distortion in the plate circuit? • Compare the phrases ‘cannot supply enough impedance’ and ‘supplies too much impedance’ with what you know about optimum plate load for an audio power stage.

✅ Before You Answer

• Be clear on whether a tetrode’s optimum plate load impedance is relatively high or low compared to what an ‘ordinary’ transformer offers at its primary • Verify what impedance matching for maximum power transfer requires in tube amplifiers (relationship between tube plate resistance and transformer primary impedance) • Check whether cost is usually the limiting factor in choosing transformer vs. other output coupling methods in basic audio tetrode stages

Question 1 of 27070

An audio-transformer is seldom used as the output device in the plate circuit of a tetrode audio-amplifier stage:

Because an ordinary transformer cannot supply enough impedance to the plate circuit

Because an ordinary transformer supplies too much impedance to the plate circuit

Because an ordinary transformer would be too costly

None of the above

Question 1 / 27070YJjifKO5D85UjXLkgHr5

Question 1 of 27070YJjifKO5D85UjXLkgHr5

An audio-transformer is seldom used as the output device in the plate circuit of a tetrode audio-amplifier stage:

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Question 1 of 27070

An audio-transformer is seldom used as the output device in the plate circuit of a tetrode audio-amplifier stage: