100W Ultimate Fidelity Amplifier

[thimios]

Hello mr. PCB Dr!

 

[still4given]

APEX BX22 improved by dragan100. long time ago.

Looks quite different.

 

[andrewlebon]

Hello Prasi
greetings is it possible to post PDF pcb pattern
warm regards
Andrew

 

[prasi]

here you go Andrew.
i do not know if someone has already built, so i am assuming its not tested.

 

[thimios]

Gerbers Dr?

 

[prasi]

here you go Andrew.
i do not know if someone has already built, so i am assuming its not tested.

Gerbers Dr?

Here you go.

 

[vargasmongo3435]

Prasi that amp is been tested it looks good bro and thank for sharing

 

[corvo72]

APEX BX22 improved by dragan100. long time ago.

Thank you Prasi, If I want to use only two pair of power transistors how much is the voltage that I must put on rails?

 

[kandimba]

It should be +65/-65 VDC.

 

[corvo72]

only +/- 10 V different?

 

[bullittstang]

Depends on your speaker impedance (load)
+/-65 for 8-ohm and I wouldn’t use at 4-ohms often or at high volume.

For 4-ohm stability and 2-ohm dips I would suggest +/-55Vdc.

You can use higher voltages, but will decrease SOA and dependability. I usually push the limits, but I also don’t mind rebuilding an amp if it blows up.

 

[corvo72]

Ok, I well noted! I normally use 8 ohm audio towers (independently speakers box connected to passive crossover). thank you bullittstang for your explanation!

 

[bullittstang]

If you use the transistors spec’d (didn’t look them up prior) you should be safe with +/-65Vdc, they are 250V 200W parts.

 

[corvo72]

using as an example, originaly BX22 with 2 pair of power transistors 2SC5200 & 2SA1943 as per sheme attached, if I decrease the power supply to 65V, the 10 ohm resistors in series to the supply of primary stage, must decrease theire value?

 

[bullittstang]

Not 100% sure - maybe someone else will chime in to confirm, but I wouldn’t think it does.
I would not use +/-65 with those BJTs, you would need to step up to their big brother version.
MJL3281/1302 or MJL4281/4302 the bigger brother

 

[apexaudio]

Thank you Mr Mile for your prompt repplay. If I want to use only 2 pair of 2SC5200 & 2SA1943 instead of six, how much should I reduce the supply voltage?
There are something to change (resistors) for what above?

Go to AX20

 

[kozard]

To build the AX40 should I use the v1.4 gerbers in post #2 of the AX40 build thread? Are those the correct/best/latest?

The top copper has a single arc (looks like to indicate the jumper wire location). Should these be ordered as single or two layer boards at PCBWAY or JLCPCB? I ask since I don't see capture pads on the top copper layer, only the arc for the jumper wire location, so I am not 100% sure.

 

[apexaudio]

P40

 

[apexaudio]

P4S

 

[Ahmadhafi]

Please share layout ax20 class h sirr