Single End Class A, we can see often.
What do we really mean by saying some amplifier is SE?
What is the opposite?
Is there amplifiers with SE in class AB? Or not?
This should not be confused with single supply vs dual supply.
What do we really mean by saying some amplifier is SE?
What is the opposite?
Is there amplifiers with SE in class AB? Or not?
This should not be confused with single supply vs dual supply.
'Push-pull' is the alternative. Single-ended is push and pull from a single transistor, while push pull uses complementary N and P transistors.
https://en.wikipedia.org/wiki/Push–pull_output
https://en.wikipedia.org/wiki/Push–pull_output
It goes back to the beginning of radio.
Single end was one tube driving the output transformer.
Push pull had 2 tubes driving the output transformer where in one half period of an output signal tube one pushed and tube 2 pulled.
In the other half period tube 2 pushed and one pulled.
Single end was one tube driving the output transformer.
Push pull had 2 tubes driving the output transformer where in one half period of an output signal tube one pushed and tube 2 pulled.
In the other half period tube 2 pushed and one pulled.
I have seen that too in books but in push pull you balance out the dc magnetic flux of the output transformer so it can be made without air gap and smaller = cheaper.
All the old shrotted radios i dismantled and rebuild had single end output. I had to wind a transformer myself to get the power.
But lets go back to solid state and our endless better amplifiers of today.
All the old shrotted radios i dismantled and rebuild had single end output. I had to wind a transformer myself to get the power.
But lets go back to solid state and our endless better amplifiers of today.
We should start with the history of development of the tube amplifier:
SE, PP, SEPP
The first amplifier was one tube with one output=Single End.
Then came PP - two tubes and two outputs (each tube was connected to one end
of the output transformer primary).
SEPP was the third and it was with two tubes (PP) and one output (Single End).
Only amplifiers with PP in their abbreviation can work in cl. AB or B (except SRPP).
SE, PP, SEPP
The first amplifier was one tube with one output=Single End.
Then came PP - two tubes and two outputs (each tube was connected to one end
of the output transformer primary).
SEPP was the third and it was with two tubes (PP) and one output (Single End).
Only amplifiers with PP in their abbreviation can work in cl. AB or B (except SRPP).
To stay with Transistor outputs.
I can see 3 cases of single end, if we have one NPN output device:
1. Resistor loaded
2. Choke loaded
3. Constant Current Source loaded
Push Pull can either use NPN+PHP, most common
or
Push Pull using NPN+NPN like Quasi, JLH way or the ZEN by Mr Pass.
Here is a figure with those ways:
(I am sure there are some more ways)
I can see 3 cases of single end, if we have one NPN output device:
1. Resistor loaded
2. Choke loaded
3. Constant Current Source loaded
Push Pull can either use NPN+PHP, most common
or
Push Pull using NPN+NPN like Quasi, JLH way or the ZEN by Mr Pass.
Here is a figure with those ways:
(I am sure there are some more ways)
Single ended (SE) refers to the type of output stage used in the amplifier. A single tube is used for the output stage in such amplifiers. A more common output stage is the push-pull output stage which uses two tubes, one for positive-going signal swings and the other for negative-going signal swings. SE amps tend to be operated in class A (constant current) operation, while push-pull types use class AB biasing configuration. Class A operation generates a lot of heat in the output stage due to constant high current dissipation, while class AB can use much less current, since the symmetry of such a stage provides some degree of distortion cancellation. Single supplies are used for the SE tube amplifiers as well as push-pull ones because tubes come in only one polarity. Transistors come in two polarities, PNP and NPN, and as a result of that, an output stage using both types will require two polarities of supply voltage, one for the NPN and the other for the PNP devices. A single-ended transistor amp can be built, that that is rarely done because of the availability of both PNP and NPN types.
SE amplifier is likely to have a higher output impedance than a P-P amp would have. That means the the speaker's impedance will affect the sound quality of the SE amp more than it would a P-P one. It's possible for an SE amp to have a lower output impedance, but it's not done in practice largely due to limited forward gain, higher output impedance, and the tendency to go into oscillation under an adverse load condition. Output transformers also carry an unbalanced DC bias current with an SE design, requiring gapped cores or excessively large cores to prevent magnetic saturation, which is not an issue in a balanced P-P design. P-P designs also cancel even harmonic distortion, and in an SE amp this distortion is present, and can often be euphonic, if inaccurate.
You CAN make an SE (solid state) amp with a very low output impedance. Even Nelson Pass (many years ago) designed one with a triple emitter follower (CCS loaded) and a s*** ton of global NFB. It would also drive a 2uF capacitor at 20 kHZ without issue.
With a variation of ZEN there is the Aleph Current Source.
That is a kind of Push-Pull. The upper current source is modulated from the output.
There is no such thing like half pregnant.
That Aleph Current Source does not determine the output voltage in any way, still only provides the bias path.
There is some level distortion cancellation going on with push pull.
Since I leant that, I haven't bothered anything not pushpull.
https://positive-feedback.com/audio-discourse/the-square-and-exponential-laws/
Since I leant that, I haven't bothered anything not pushpull.
https://positive-feedback.com/audio-discourse/the-square-and-exponential-laws/