That is a beautiful amplifier, and I think it was very clever
of you to raise the bias and increase the gain of the current
source.
😎
of you to raise the bias and increase the gain of the current
source.
😎
Member
Joined 2009
Paid Member
I think that's clever, but kind of 'cheating' 😀 - essentially you increase bias to avoid leaving Class A, but you may have found a way to do this more economically and that deserves some exploration !
The clever part is doing both. If you increase the bias to
the value of the largest peak output current, you are free to
set the effective gain of the current source as high as you
like, approaching 100% of the output. With the bias at 1/2
the peak current you are constrained to a gain of about 50%
of the output current.
I have built several amps using the higher bias, and it works
like glue, although it runs twice as hot.
😎
the value of the largest peak output current, you are free to
set the effective gain of the current source as high as you
like, approaching 100% of the output. With the bias at 1/2
the peak current you are constrained to a gain of about 50%
of the output current.
I have built several amps using the higher bias, and it works
like glue, although it runs twice as hot.
😎
Member
Joined 2009
Paid Member
It's certainly not an idea that would have sprouted from my grey matter so I hope we will see some more things from Wensan...🙂
From the beginning,
I never thought the distortion feature of such SRPP circuit worked in Class AB mode will better than the distortion feature of a pure Class A monster.
But I thought the distortion feature of such SRPP circuit worked in Class AB mode will not worse than the distortion feature of a normal Class AB amplifier.
And then, I found the problem about the BJT's saturation in the SRPP circuit.
So I add some parts to prevent the BJT go into saturation and solve the problem.
Now,
I still don't think the distortion feature of such SRPP circuit worked in Class AB mode will better than the distortion feature of a pure Class A monster.
But I think the distortion feature of such SRPP circuit worked in Class AB mode will better than the distortion feature of a normal Class AB amplifier.
I never thought the distortion feature of such SRPP circuit worked in Class AB mode will better than the distortion feature of a pure Class A monster.
But I thought the distortion feature of such SRPP circuit worked in Class AB mode will not worse than the distortion feature of a normal Class AB amplifier.
And then, I found the problem about the BJT's saturation in the SRPP circuit.
So I add some parts to prevent the BJT go into saturation and solve the problem.
Now,
I still don't think the distortion feature of such SRPP circuit worked in Class AB mode will better than the distortion feature of a pure Class A monster.
But I think the distortion feature of such SRPP circuit worked in Class AB mode will better than the distortion feature of a normal Class AB amplifier.
The blue light panel is more beautiful in the dark.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
The above #66 analysis stands also for a complex swinging and dipping speaker load, or just on nominal resistor? SRPP works best when designed for defined loads in general?
The impedance of a 8 ohm speaker sometime lower than 8 ohm frequently.
So how to determine the largest peak output current is very tricky.
But depend on the transition curve of a transistor,
A transistor with higher bias current always has better distortion features.
Because the working point is farther from the deflective point of the curve.
Building a pure Class A monster is a dream to me.
But my financial situation won't allow me to do it.
But my financial situation won't allow me to do it.
Wensan,
Congratulations! I just saw pictures of your "Cookie" amp, and it must say that it's very cute! I like alternative ideas, so just keep your spirit high, and the success will come. Money comes and money goes, but the knowledge stays and it never gets consumed, only multiplied....
Thanks for sharing
Vix
Congratulations! I just saw pictures of your "Cookie" amp, and it must say that it's very cute! I like alternative ideas, so just keep your spirit high, and the success will come. Money comes and money goes, but the knowledge stays and it never gets consumed, only multiplied....
Thanks for sharing
Vix
Pass Labs
Dear Nelson and Wensan,
Two great men together talking about audio (amp's).
This feels like something nice will grow out of this meeting and I hope that Wensan will achieve his goals ! Like Nelson did !
Thanks both of you for this news.
Yours truly,
Audiofanatic (José )
Dear Nelson and Wensan,
Two great men together talking about audio (amp's).
This feels like something nice will grow out of this meeting and I hope that Wensan will achieve his goals ! Like Nelson did !
Thanks both of you for this news.
Yours truly,
Audiofanatic (José )
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