Creek 5350MK2 (5350-II 5350 Mark 2 5350-MK2) - circuit descr. arround Q12a wanted

[tiefbassuebertr]

For this amplifier, I need a little bit help. I don't understand the meaning of Q12a. There might be even a misprint Who knows more? Maybe "X-PRO" ?

[tiefbassuebertr]

Nobody here with the appropriate informations ???

[dudohifa]

Q12 and Q12A are drivers tranzistors,Q12A is pin out misprint

[tiefbassuebertr]

Originally Posted by dudohifa

Q12 and Q12A are drivers tranzistors,Q12A is pin out misprint

Thank you, but that there are a misprint I also know. But I don't believe to a faulty pin out. The driver stage must be a differential amp with Ube current source. I guess, that the drawing gate connection of Q12a isn't correct. Now the question is, where goes the gate wire of Q12a?

For better understanding the schematic I have perform a redrawing (PDF file at botton). Please ignore the device numbers except Q12a

[jony]

Read this
http://www.ant-audio.co.uk/Theory/N-...0linearity.pdf
Q12a is sample M4

[dudohifa]

Originally Posted by jony

Read this
http://www.ant-audio.co.uk/Theory/N-...0linearity.pdf
Q12a is sample M4

Now is all clear,no misprint

[tiefbassuebertr]

Originally Posted by jony

Read this
http://www.ant-audio.co.uk/Theory/N-...0linearity.pdf
Q12a is sample M4

Thank you very much for this advice. I haven't respect the follow:

"For this circuit to work the Vth of the output devices should be lower than Vth of the drivers by a good margin. This is easily achieved if the output devices are low threshold D-MOSFETs (often called “Logic Level”) with Vth<2V and drivers are standard threshold D-MOSFETs with Vth in the area of 3.5-4V.
If all the FETs had the same Vth it would be necessary to provide an additional bias voltage for FET M4"

[x-pro]

Originally Posted by tiefbassuebertr

Nobody here with the appropriate informations ???

You can always ask me - I've designed 5350 and it is my circuit idea.

Cheers

Alex

P.S. I don't read DiyAudio much lately so I've missed that thread till now. You could PM me. Where did you get the 5350 diagram? I haven't seen it published yet.

[tiefbassuebertr]

Hello Alex,
nice to hear from you.
Either I have this schematic from the forum here, or the Company Creek had send to me as a PDF attachement by asking for their download aera (I need it for repair and maintenance of some defective 5350 devices, some years ago). Only now I understand the topology more exactly, because so far I used instead the necessary logic level output MOSFETs normal IRF540.
Next time I will check your topologies about
http://www.ant-audio.co.uk/Theory/N-...0linearity.pdf
by simulation. As i know, this topologies are further developments from Bengt Ollson's idea, "Better Audio from non complements?" from Bengt Olsson (B. Olson), go to Electronics World + Wireless World, December 1994 page 988

About the weblink
Only N-Channel MOSFETs (NMOS); better Audio from non complements by Audio Power?
I have create an overview about all me known topologies with only one kind of output power MOSFET resp. BjT - perhaps of interest for you. I don't know other place with such overview, because most topologies based to the so called "true complementary" output stages. I hate this through only perfection in theoretic world and schematic.

Currently I am looking for a power buffer alternative, which brings approximately the same low THD results like a Circlotron (see below) - for me presently the best known topology, but not good to implement in existing faulty amplifiers .
What do you think - is this possible by the topology of Fig 5? go to URL
http://www.ant-audio.co.uk/Theory/N-...0linearity.pdf

Thank you very much for your estimations

[x-pro]

Originally Posted by tiefbassuebertr

Hello Alex,
nice to hear from you.
Either I have this schematic from the forum here, or the Company Creek had send to me as a PDF attachement by asking for their download aera (I need it for repair and maintenance of some defective 5350 devices, some years ago). Only now I understand the topology more exactly, because so far I used instead the necessary logic level output MOSFETs normal IRF540.
Next time I will check your topologies about
http://www.ant-audio.co.uk/Theory/N-...0linearity.pdf
by simulation. As i know, this topologies are further developments from Bengt Ollson's idea, "Better Audio from non complements?" from Bengt Olsson (B. Olson), go to Electronics World + Wireless World, December 1994 page 988

About the weblink
Only N-Channel MOSFETs (NMOS); better Audio from non complements by Audio Power?
I have create an overview about all me known topologies with only one kind of output power MOSFET resp. BjT - perhaps of interest for you. I don't know other place with such overview, because most topologies based to the so called "true complementary" output stages. I hate this through only perfection in theoretic world and schematic.

My topology pre-dates Bengt Olsson's article (Creek 4240 uses my circuit and was in production in 1993 and the circuit itself was developed in 1992), and it is quite different in approach.

Originally Posted by tiefbassuebertr

Currently I am looking for a power buffer alternative, which brings approximately the same low THD results like a Circlotron (see below) - for me presently the best known topology, but not good to implement in existing faulty amplifiers .
What do you think - is this possible by the topology of Fig 5? go to URL
http://www.ant-audio.co.uk/Theory/N-...0linearity.pdf

Thank you very much for your estimations

I think that with 1.5 A idle current the distortion of my circuit could be very low. In essence, 4th MOSFET adds a local NFB and reduces the distortion considerably in comparison to a plain follower. Circlotron has its own problems and I like the sound of my circuit (obviously). Here is a link to my simulation results showing the effect of the added MOSFET:

http://www.ant-audio.co.uk/Theory/Comparision1.gif

Cheers

Alex