100W Ultimate Fidelity Amplifier

[bullittstang]

I collected and listened to the so-called APEX AX-20,
about which I want to share here. In fact, this is a classic amplifier
with all the improvements from Douglas Self’s textbook (and recommendations from local colleagues).
Compared to Apex AX-14, this amplifier sounds much more adult:
More dynamic sound, excellent control of 4 pieces 8 "bass. Bass is excellent.
Clear low. In the 14th, in comparison, a little tightened, just a little because of what
it seems that it’s even a little more.
who whant to do (gerbers) Apex_AX_20

PCBWay says the "author will not allow download of gerbers" and when I "add to cart" it loads a 6.7mm x 12.8mm board - can't be correct size??

 

[apexaudio]

hi i want to use this protect on ax14. but ax14 dont have protection out.
so i try to take it from b500 schematic but i am not good on it and need to some one check it please

the resistor values and capasitor is right? and if i make mistake pls tell me where. thank you

Use protection out from AX22 and use DC555S protect...

 

[karachay]

Use protection out from AX22 and use DC555S protect...

ty for answer mr mile. you mean like this?

but for protection i cannot use pa protec? i was like it for 15v for xlr circuit and thermal protection too. and i want to use regulated amp psu one of yours is that all can be use together? sory for many questions and for my bad english. thank you

ah i forget my transformer giving me 2x50vdc and 2x20vdc. i rewind secondary. thank you again for all your help.

 

[karachay]

ty for answer mr mile. you mean like this?

but for protection i cannot use pa protec? i was like it for 15v for xlr circuit and thermal protection too. and i want to use regulated amp psu one of yours is that all can be use together? sory for many questions and for my bad english. thank you

ah i forget my transformer giving me 2x50vdc and 2x20vdc. i rewind secondary. thank you again for all your help.

Re drawing pcb for protec. tomorrow i can finish and start pcb ty mr. mile

 

[karachay]

i am stuck again any one can tell me which one is right polarity for C6 100uf 16v??

 

[Zinyx]

Maybe try to use AX-14P

 

[karachay]

Maybe try to use AX-14P

i start for ax14 man ty just there is that cap is different on pcb and on schematic. i dont know which one is right. i made before this ax14 its not work i throw away cause thin lines and repair make them trash. so i making again now but i will draw new pcb with protection.

so i need to know which polarity is right. on schematic or on pcb.

 

[prasi]

Re drawing pcb for protec. tomorrow i can finish and start pcb ty mr. mile

On your sch, it's connected the correct way.

Edit: mistake in typing

 

[Dirttracker73]

I think the schematic is correct but I believe C6 polarity does not matter. C6 could be non-polar electrolytic but you can use an inexpensive polar electrolytic because it has very little load. Anyone please correct me if I am wrong.

 

[karachay]

Ty for answers i chech some pics from who make this amp. All use polarity from pcb. Ty for answers

 

[karachay]

i finish redrawing. pls have a look. i take out line under the R24 for protec. this can make a problem on it voice? or any desing faults if you see pls write here so i can learn more. thank you for all helps.

i will make it next week so i am just waiting for your answers...


i will put here gerber files and all i have after see its work. ty..

 

[Gurpreet Turna]

TP2 preamp

TP2 one channel schematic without PSU.

Hello Mr. Mile, can u please update TP2 with TP3 (bass, mid and treble).
Regards,
Gurpreet

 

[apexaudio]

Hello Mr. Mile, can u please update TP2 with TP3 (bass, mid and treble).
Regards,
Gurpreet

There is no TP3, go to TB3.
Regards

 

[karachay]

Use protection out from AX22 and use DC555S protect...

hi mr mile pls can you just look a little to that pcb i trying to make, maybe you can see some mistakes. thank you .

 

[karachay]

and you said different voltages abouth it.

some where you write "Circuit was tested on +/-90V rail voltage,
but with single pair 2SC5200/2SA1943 +/-56V is maximum."

and another page you write "I suggest rail voltage +/-45V for single pair".

i need rewind transformer cause i read wrong too and make it 50-0-50vac before. now i opening again going to make it 40-0-40Vac. is this too much for ax14?

 

[Gurpreet Turna]

There is no TP3, go to TB3.
Regards

I already have TB3, but I think TB3 is only tone control with buffer(if I m right). TP2 is Preamp with tone control, but there are 2 band (bass & treble). If 3rd band ( mid) add in this Preamp that's awesome.
Regards
Gurpreet

 

[still4given]

and you said different voltages abouth it.

some where you write "Circuit was tested on +/-90V rail voltage,
but with single pair 2SC5200/2SA1943 +/-56V is maximum."

and another page you write "I suggest rail voltage +/-45V for single pair".

i need rewind transformer cause i read wrong too and make it 50-0-50vac before. now i opening again going to make it 40-0-40Vac. is this too much for ax14?

I think that is too much for a single pair. You can get by with that for 8ohm only but you will need good heatsinking. I doubt you would notice any benefit from the higher voltage.

 

[karachay]

I think that is too much for a single pair. You can get by with that for 8ohm only but you will need good heatsinking. I doubt you would notice any benefit from the higher voltage.

ty for answer my friend. i just trying make what is suggested. some times i misunderstand cause of my bad english and making mistakes.

what you suggest for transformer for single pair.

 

[kandimba]

ty for answer my friend. i just trying make what is suggested. some times i misunderstand cause of my bad english and making mistakes.

what you suggest for transformer for single pair.

You should have 33-0-33 VAC on your transformer.

 

[karachay]

You should have 33-0-33 VAC on your transformer.

Ty soo much