100W Ultimate Fidelity Amplifier

[olafk]

Thanks,

It is playing fine now with the zobel attached. I listened to it for a while. Sounds very good as expected. The gain is a little lower than some of the other Apex amps. When I find my camera I will show some square and sine waves.

Blessings. Terry

Super.
I'm just a hobbyist. If an amplifier is not working as expected, I'm always in trouble .
But get it running is exciting.

regards.

 

[still4given]

I finished populating the A9 except for the MOSFETs which should arrive tomorrow or Saturday. I have looked back through the thread but can't find what the bias setting should be. Can someone please let me know what it should be?

Thanks, Terry

 

[sajti]

Add this compensations.

I would try to replace the MJE340/350 pairs with 2SC3503/2SA1381. I used this topology many times, and faster devices give better results!

Sajti

 

[apexaudio]

I finished populating the A9 except for the MOSFETs which should arrive tomorrow or Saturday. I have looked back through the thread but can't find what the bias setting should be. Can someone please let me know what it should be?

Thanks, Terry

Set 30-50mA,
Regards

 

[apexaudio]

I would try to replace the MJE340/350 pairs with 2SC3503/2SA1381. I used this topology many times, and faster devices give better results!

Sajti

I use comon parts for test and diy, can be upgrade leter,
Regards

 

[sajti]

I use comon parts for test and diy, can be upgrade leter,
Regards

Understood, but my experience, that MJE340/350 can results oscillation, if use as predriver.

Sajti

 

[altclick]

Olaf,
Thanks for posting the Sprint Layout file for A9 !!!
Now if someone would just do the same for A23 it would be a great help. Some of us are not yet very good at starting layouts from scratch..

Vic

 

[3388ton]

free http://www.upload-thai.com/download...W50LUxheW91dDUwX1BvcnRhYmxlLnJhcjUyMDY5NDMzOA
Sprint-Layout50_Portable.rar

 

[apexaudio]

A23 test 15kHz 1V/div 8r with 470nF in paralell.

 

[44250]

Olaf,
Thanks for posting the Sprint Layout file for A9 !!!
Now if someone would just do the same for A23 it would be a great help. Some of us are not yet very good at starting layouts from scratch..

Vic

 

[44250]

A23 test 15kHz 1V/div 8r with 470nF in paralell.

looks familiar...

 

[altclick]

Thanks 44250 !!
Now I have no excuses ..... gotta build it.

 

[44250]

Thanks 44250 !!
Now I have no excuses ..... gotta build it.

that is re-drawn version of a first board. the difference is in a way that grounding is connected and Mile APEX has given me detailed instructions and corrected me whenever i got things wrong - so he is the one to say THANKS to...

 

[44250]

https://www.youtube.com/watch?v=8swdIbX4Gok&feature=youtu.be

 

[still4given]

Hi 44250,

I have begun populating my boards based on your layout. I see you have added a few caps and increased others ten fold. May I ask why? Do you have a schematic for your build?

Thanks, Terry

 

[still4given]

Hi 44250,

I have begun populating my A23 boards based on your layout. I see you have added a few caps and increased some others ten fold. May I ask why? Do you have a schematic for your build?

Thanks, Terry

 

[44250]

100nF are aded for decoupling, and 100u marked on pcb should be 10uF as in schematic.

 

[still4given]

You also added 1000u+100n to each rail and increased 100u to 220u. Was this under advisement of Mile or did you just feel the circuit needed it?

Thanks, Terry

 

[olafk]

A33

Hi, I started to design a layout for the A33. This is the very first draft for the input stage. I do not know if it's a good idea to share the PCBs in two parts. This gives a better handling during the test. If everything works out, we can make a complete PCB. Recommendations very welcome! Maybe someone can look at the design, I have to double check everything.

Regards Olaf

 

[sonal kunal]

Hi Olaf, nice work I started pcb layout for A33 today. I was thinking to put offset correction section to right or left side of signal section. Your layout has given me some idea. Just little progress on pcb .

Regards
Sonal