Source for VAS transistors Europe

[Bensen]

Hello,

I'm looking for quite a while now for a source to buy good VAS transistors, sofar I haven't found only one.
I'm looking for minimum one of following couples:

2SC2911/2SA1209 (Profusion...)
2SC3955/2SA1540
2SC3953/2SA1538
2SC3600/2SA1406
2SC3423/2SA1360
BF871/BF872

Who can help me?
Thanks in advance

 

[Mooly]

2SC2911 and 1209,

SANYO|2SC2911|TRANSISTOR, NPN, TO-126 | CPC

SANYO|2SA1209|TRANSISTOR, PNP, TO-126 | CPC

 

[Bensen]

Thanks Mooly,

I see that both parts are from an other Hfe Group (R+S).
I realy would like to match the VAS transistors in order to minimalise the effect on the IPS (diff complementairy with dual JFET's).

I have to less experience to tell how important a good matching is between the VAS transistors.
Can anybody give me an idea whether this really makes a difference.


Does anybody else has a good source to find any of these transistors.

Thanks

 

[Mooly]

Maybe if you posted the circuit we could advise better...

Is it fully symetrical ? as I normal think of a single VAS device.

 

[Bensen]

IPS: dual JFET cascoded with dual BJT
2nd compl diff stage
VAS BJT (I'm also thinking to put 2SK216 + 2SJ79 here?)
Driver
BJT OPS

I'm having all components except for good BJT's for the VAS stage.

Don't look to much to the circuit, I know it's a mesh, I'm still in the designing/trial phase.

 

[Mooly]

Thanks for posting the circuit.
I honestly don't know what the ultimate effect of say badly mismatched devices might be but I suspect it will be small in the overall scheme of things. And you could always match devices pretty closely yourself anyway if you got a few of each.

Perhaps somebody else with more experience of this topology could advise you better.