it is possible to change all tr to BD139?

[Wik]

 

[Brijac]

If by all tr you mean changing bd140 to bd139, then no.

 

[WhiteDragon]

139 is NPN 80 volt package about 1 watt.

+/- 50 volt or 100 volt supply. No

Not sure the application, 100 volt supply driven speaker? with 1 watt package.
100 volt is enough for 150 to 250 watts.

otherwise what is shown requires NPN and PNP transistor.
139 / 140 general purpose, average gain, very slow

 

[john_ellis]

Hi WD - BD139/140 are not "very slow".
Have you actually measured any?

 

[WhiteDragon]

Yes correct John I understand what you are saying.
All depends on application and load.
And yes Ft can be up to 100/ 140 Mhz

 

[Citizen124032]

There will be a large output offset, as there is not enough open loop gain with only these two stages.
Even if the 910Ω resitor is combined with a cap. And it could run to near any of the two rails.
Are there 560Ω resistors in the emitters of the last stage?
Connecting collector2collector at the output requires some smart circuitry.