100W Ultimate Fidelity Amplifier

[shravanth]

hello, can I replace BC639,BC640 with BD139 , BD140 so that I can mount it on heat sink easily and I am replacing MPSA13 with BD681

 

[apexaudio]

hello, can I replace BC639,BC640 with BD139 , BD140 so that I can mount it on heat sink easily and I am replacing MPSA13 with BD681

Yes, BC639/640 and BD139/140 have same pins order, but on BD681 pins have different order...

 

[Teti]

Sorry bout that guys. I was just wondering if somebody know about this amp, since this is about ultimate fidelity amp??????

 

[apexaudio]

Sorry bout that guys. I was just wondering if somebody know about this amp, since this is about ultimate fidelity amp??????

Can't be 'ultimate fidelity amp' with this overshoot and ringing on 10kHz with 1uF and 3R9 in parallel
AX11 is much more fidelity on real life speakers with pasive xover

 

[apexaudio]

APEX FX8

Simple amp with HITACHI mosfets.

 

[apexaudio]

APEX AX13

Upgrade in suplly

 

[warrior007]

With FX8 circuit, is it possible to use +/-65VDC? what parts need to be change? Can you share the PCB for this also, Thanks!!!

 

[ahmadfay]

in my place, I find it hard to get mpsa13, can I replace it with another transistor (BD139 or MJE 340) Sir Alex?

 

[wintermute]

OT posts removed.

 

[apexaudio]

With FX8 circuit, is it possible to use +/-65VDC? what parts need to be change? Can you share the PCB for this also, Thanks!!!

It's not possible, +/-40V is maximum.

 

[apexaudio]

in my place, I find it hard to get mpsa13, can I replace it with another transistor (BD139 or MJE 340) Sir Alex?

MPSA13 is darlington, you can replace it with BC517 but pins are reverted. It is possible to use some TO126 darlington like BD681 but pins order is different.

 

[shravanth]

Apex sir so i Can change bc639,bc640 witg bd139,bd140 . . . .

 

[apexaudio]

Apex sir so i Can change bc639,bc640 witg bd139,bd140 . . . .

Yes, also you can use BF471/472 in TO126 case or BF871/872... and there is many 2SA/SC, 2SB/SD...

 

[shravanth]

AX-11

Yes, also you can use BF471/472 in TO126 case or BF871/872... and there is many 2SA/SC, 2SB/SD...

ohhh... apex sir i am making layout with SMD resistors and can i use SMD BC546 at the input stage

 

[apexaudio]

ohhh... apex sir i am making layout with SMD resistors and can i use SMD BC546 at the input stage

Yes, SMD BC546 is BC846.

 

[shravanth]

amp

Yes, SMD BC546 is BC846.

thank you sir i will just upload my pcb layout

 

[apexaudio]

APEX PX6

Line Preamp based on AX11 topology

 

[farjon]

Line Preamp based on AX11 topology

Could it be used as a headphone amplifier? Perhaps with an series output resistor?

 

[apexaudio]

Could it be used as a headphone amplifier? Perhaps with an series output resistor?

No, this is headphone amplifier based on AX11 topology.

 

[apexaudio]

Tone Control Adapter

This circuit can be add to AX11 for tone control.