A Directory of Apex Audio Amplifiers

[burnmaster]

Thanks.
Mile, do you approve the idea of bridging the A40 high power boards?
2 chips per channel.
I made 12, so I got enough.
Because you liked my sound some time ago, I made a video today with my other favorite amplifier.
It is made of garbage items. Discontinued by TVs and any appliances. I used a box of technic with arrows)))))
And for my new A40 I'll make new speakers with those Visaton.

YouTube

 

[burnmaster]

 

[44250]

nice!

 

[burnmaster]

The left channel is almost ready....)))))

 

[burnmaster]

These are measurements at 800 mA of the end resistors.
Predictable result 30 watt class A.)))))
However, this is just one shoulder of one channel.
There are 3 more boards for the whole amplifier.

 

[rehman]

hi there i made A40 by following the schematic. pcb is my own design but i have some issues. offset pot is not working. there is constant high output DC which cannot be adjusted by offset pot. when pgnd is disconnected, there is about 1.5v. i connected the speaker and it gives output but 80% distorted. iam trying to figure out the issue but there is no improvement. i need help.

 

[Agus sugiono]

Hello ,,,,, For ax17, if you use transistor 5200 9, how many volts do you install?
And which component should be changed, if you use high volt?

 

[nareshn]

Hi All. Request your inputs.Which is Apex's lowest part count power amp. Is it AX6 ? Thanks.

 

[xrk971]

FX8 or FH9 is quite low parts count, proven to work well, built by many, and well documented. I don’t know much about AX6. FH9 can be assembled in about an hour.

@burnmaster: Nice work! I haven’t been here in a while so sorry for later replies.

@rehman: you might ask over in main Apex thread.

 

[apexaudio]

Hi All. Request your inputs.Which is Apex's lowest part count power amp. Is it AX6 ? Thanks.

APEX A3

 

[apexaudio]

Hi All. Request your inputs.Which is Apex's lowest part count power amp. Is it AX6 ? Thanks.

APEX FX4

 

[prasi]

APEX FX4

Here is layout posted in retro amp thread.

 

[nareshn]

APEX FX4

Thank You

 

[xrk971]

Updated post 1 with FH9 Gerber file with solder pads on both sides.
100W Ultimate Fidelity Amplifier

 

[tozeyana]

PSU and Protection

Thank you Karl vd Berg,
I just updated the first page directory with the above 2 preamps and also a PAU + stereo protect circuit I saw on same page.

The schematics are really adding up so far! 🙂 Count is currently 43 schematics on Post 1.

PSU and Protection:

Any help with PCB pdf for this PSU please

 

[kozard]

I don't know if this is the best place to post but I would like some advice/help with A40. I went ahead and ordered the PCB attached in the A40 build thread but it looks like there is a problem.

I have attached pictures of shorts on the front side.

I assume I should dremel away the top copper trace. (The gerber files in this thread have a top copper layer with one copper arc.) It looks like the amplifier will badly malfunction with the shorts to the bias trimmer and resistor.

Perhaps this post can serve as a warning to others regarding the gerbers in the A40 build thread. I hope that the amplifier works when assembled with these PCB after the dremel fix. The parts are fairly expensive for two of these boards so I hope the gerbers attached to this thread are good... If there are other problems with the gerbers I would appreciate a warning before I waste all the components and time assembling this.

 

[rsavas]

Looks as if the top copper trace was to be a wire jumper so looks as if you have to isolate it, cut out any shorts that the Cu trace creates

 

[Bruce@bluff]

Would it be possible to modify the FX 4 to run off IRFP240/9240 mosfets ?

 

[Astaro]

re you sure that in Apex A40 exactly bd139 should be on the radiator? They are in the mode of diodes... Maybe those mje340/350 that are connected to them in series

 

[desislavov]

does anyone know what is this capacitor for ?