Looking for a good NPN audio driver for my power amp.

[Progg70]

I have used BD829 as audio driver. They don’t make them any longer. Anyone no what I can use instead?

I have the 2SC2922 for the output in my power amplifier. Can any one tell me what is very good audio transistor NPN who I can use as a driver before the 2SC2922?


Regard

Progg70

 

[AndrewT]

Hi,
you could try
2sa649/c669 120V
2sa649a/c669a 160V
2sa1535/c3944 150V
2sa1535a/c3944a 180V
2sa1220/c2690 120V
2sa1225/c2983 160V
2sa1606/c4159 160V
2sa1930/c5171 180V
which all have fT > 80MHz, but some have a poor high voltage SOAR.
for a slower, fT 30 to 40MHz, but very robust driver then try
MJL15032/3
MJL15034/5

 

[Progg70]

the 2SC2922 is had to get

Thanks…

I discover that the 2SC2922 is hard to get. Is there some good one with similar physic mount out there.

Regard

Progg70

 

[MikeB]

Hi !

A similar physic mount might get difficult...
Try www.schuro.de , they have the sanken 2sc2922 ! Not too cheap, but preselected originals...

Mike

 

[AndrewT]

Hi,
try 2sa1295/c3264, but it is also Sanken. Both are MT200 (Fpack) and I think very few others make them.
www.rapidelectronics.co.uk sell them both. You could try www.dalbani.com

 

[Progg70]

Thanks every one...

I need only to mount the transistor directly to the heat sink. It doesn’t matter what the body looks like. The performance is more importen.

 

[jackinnj]

Randy Slone used the 2SB649A + 2SD669A in his high power Lateral MOSFET amplifiers -- Andrew has already mentioned the device -- these are TO-126 devices.

 

[DR_PONJA]

Chack out 2SA1943.

 

[edl]

Dear Progg70,

BD829 is a 80V, 1,5A, 8W, 250MHz device in TO-202 package.
Let's use BD139 instead them. It's a dirty cheap, "always available" device, with 80V, 1,5A, 8W (improved to 12,5W), 250MHz specifications, in TO-126 package.


Regards,

 

[AndrewT]

Hi Edl,
Bd139, fT=250MHz. Which makes can achieve this? Can you confirm if the compliment BD140 is similar?

 

[Progg70]

Whooaow… nice. Exactly the information I’m glad for. Of course I’m going to try it out. Here is the data for the transistors.

BD139 NPN 12,5 80 1,5 40/250

BD140 PNP 12,5 80 1,5 40/250

Thanks a lot.

 

[edl]

Hi Edl,
Bd139, fT=250MHz. Which makes can achieve this? Can you confirm if the compliment BD140 is similar?

Dear AndrewT,

This device is used in 28-30MHz RF transmitters, or even at 100MHz links!
Here is the datasheet with fT:
http://www.alphalink.com.au/~cambie/BD139refA.gif

BD140's fT is "only" a 75MHz, as you can see.

 

[Geoff]

Bd139, fT=250MHz. Which makes can achieve this? Can you confirm if the compliment BD140 is similar?

BD140's fT is "only" a 75MHz, as you can see.

The Philips datasheets (the only ones that I have found for these devices that quote the fT) give 190MHz for the BD139 and 160MHz for the BD140 (@ Ic = 5mA, Vce = 5V, f = 100MHz)

 

[AndrewT]

Thanks Edl & Geoff,
wide tolerance/spread on these frightens me off from a matched pair.

 

[edl]

Dear Geoff,

Thanks for the info!

Regards,

 

[Christer]

The Philips datasheets (the only ones that I have found for these devices that quote the fT) give 190MHz for the BD139 and 160MHz for the BD140 (@ Ic = 5mA, Vce = 5V, f = 100MHz)

True, but many manufacturers don't spec ft at all for these transistors. That doesn't necessarily mean theirs are worse, but they don't promise anything, so who knows? For instance, since the threadstarter will probably buy them from Elfa, he will get ON devices, which have no ft spec in the datasheet. Ironically, Elfa used to sell Philips devices of these types, but have now switched to ON.

 

[edl]

dear all,

has anyone got information about fT of mje340-mje350 devices?

thanks,

________

http://www.diyaudio.com/forums/showthread.php?threadid=7648
i've found this thread. they say 20-30 and 8-12MHz...