100W Ultimate Fidelity Amplifier

[vargasmongo3435]

i made one more PCB .
Here drivers are BD139 and BD140 .

Lamp in primer on transformator glow high .

There is no trimer because i use potentiometer with wires .
All jumpers are there ....

sir take your time, the first time I power up my AX-14 I have a problem of a short from the screw holes it was touching the heat sink I just cleaned with a drill and all good to go 🙂

 

[olafk]

OK, here for all they want to have fun the files for printing 😉

Nice amplifier again. Thanks to Mile.

regards Olaf

 

[apexaudio]

OK, here for all they want to have fun the files for printing 😉

Nice amplifier again. Thanks to Mile.

regards Olaf

Thank you for this pcb design and test.
Regards

 

[still4given]

OK, here for all they want to have fun the files for printing 😉

Nice amplifier again. Thanks to Mile.

regards Olaf

Hi Olaf,

Would you mind posting a mirror silk?

Thanks, Terry

 

[olafk]

Hi Olaf,

Would you mind posting a mirror silk?

Thanks, Terry

Hi, is this ok?
regards Olaf

 

[desislavov]

sir take your time, the first time I power up my AX-14 I have a problem of a short from the screw holes it was touching the heat sink I just cleaned with a drill and all good to go 🙂

sir , i don`t have any screws in my PCB .

Now i take off all transistors . Every one from them is in perfect condition .....
And now i realy dont have idea what to do .....

This simple amplifier isn`t so simple 🙂

 

[vargasmongo3435]

sir , i don`t have any screws in my PCB .

Now i take off all transistors . Every one from them is in perfect condition .....
And now i realy dont have idea what to do .....

This simple amplifier isn`t so simple 🙂

uhmm .... ok, all small signal transistors have the correct lead orientation ? check EBC and compare data from to the original layout

Regards
Juan

 

[kool lites]

Can I ask if 2SA1535 and 2SC3944 are suitable replacements for 2SA968 and 2SC2238? these are stocked by my local store.

 

[still4given]

Hi, is this ok?
regards Olaf

Yes!

 

[danielturcu]

Thanks @olafk......
@ still4given you're so fast......The maximum power supply for Ax14 is ....?
Regards,
Dan

 

[still4given]

In the morning I will cut a heatsink angle and install the drivers and outputs. I'll let you know when it's singing.

 

[AndrewT]

Hi, do you mean that it is normal at 20kHz and high amplitude?
With normal music and lower frequency square wave all is cool.

A 14V 20kHz sinewave is a heavy signal for a Zobel resistor.
A 20kHz squarewave sends out double the power (into a resistor) and all that extra power is @ or above 60kHz.
That results in a lot of heat. But it gets worse than that. The capacitor reactance gets lower as the harmonics rise and this results in more than double the power into the Zobel resistor.

 

[olafk]

A 14V 20kHz sinewave is a heavy signal for a Zobel resistor.
A 20kHz squarewave sends out double the power (into a resistor) and all that extra power is @ or above 60kHz.
That results in a lot of heat. But it gets worse than that. The capacitor reactance gets lower as the harmonics rise and this results in more than double the power into the Zobel resistor.

Hi Andrew, thanks for the explanation.

regards Olaf

 

[olafk]

In the morning I will cut a heatsink angle and install the drivers and outputs. I'll let you know when it's singing.

That's really fast! Looks good!
I'm curious what you say about the sound.

regards Olaf

 

[olafk]

A14 Sprint-File

Regards Olaf

 

[danielturcu]

@olafk , can I use 2sa1837/2sc4793 instead of 2sa968/2SC2238?
Thanks.

 

[olafk]

@olafk , can I use 2sa1837/2sc4793 instead of 2sa968/2SC2238?
Thanks.

Yes, that is the original circuit.

 

[apexaudio]

That's really fast! Looks good!
I'm curious what you say about the sound.

regards Olaf

Is sound same as your first A14 from post #3990?
Regards

 

[olafk]

Is sound same as your first A14 from post #3990?
Regards

Exactly!
But sound is very subjective.
A14 has not so much individuality and character like a A9 😎. It's more a general purpose amplifier. Neutral and balanced across all frequency ranges.

regards Olaf

 

[desislavov]

finally worked !!!

Problem was faкe transistors 2N5401.
Now all signal transistors are BCXXX .

I have made six chanels