CK-KumisaIII amp output transistor replacement?

[h_a]

I want to build this nice headphone amp, designed by Benny Jørgensen and improved by Cavalli and Kan, it seems to me to be a very nice headphone amp!

(More infos are here by the way)

However it uses BD139/BD140 as output transistors, and I read recently that only the original Philips parts are recommended (long discontinued), so I thought of using the OnSemi MJE15030 instead.

What do you think? Is this a suitable (or better) replacement?

Just wasting money?

Cheers, Hannes

PS:
Datasheet MJE15030

 

[Clutz]

I suggest that you go and and make a post aboutthis over at Headwize.com where the official support thread for the CKKIII is. The middle K in the CKKIII frequents that board regularly and would be able to give you a very well informed opinion.

 

[h_a]

Thanks for your reply!

It's just that I'm not registered over there and I'm too lazy to do so now.

However I contacted K and he suggests the MJE243/253. Above stated MJE15030 have incompatible pin-out by the way.

Cheers, Hannes

PS: the support is really outstanding! I just mailed him and got immediate and helpful reply!

 

[h_a]

Just by looking at datasheets I would guess that a BD179/BD180 should also be very nice; it has a low Ft of 3 MHz though (the original BD139 from Philips had 160 Mhz, however the datasheets of BD139 made by other different manufacturers don't state a Ft at all).

So I anyone could tell me the gain of the output stage I would know how that would affect bandwidth (I would guess that it doesn't matter at all).

Cheers, Hannes