Simple question...

Status
Not open for further replies.
Hi ya all,

Please take a look at the attached image. This is the output stage of my preamplifier. I'm wonderig, which one of those two transistors (Q17, Q18) should I mount on the heatsink of output trannies. My guess is Q17, but I'm not sure. What will happen if I mount both trannies on the heatsink? Better or worse regulation (not that it really matters in this case since this is a preamp, not a power amp, but I want to make it right)?

Thanks in advance!
 

Attachments

  • gr_bias.gif
    gr_bias.gif
    4.2 KB · Views: 174
still interested...

I need this answer since I'm in a phase of making the PCBs. I've made them with both trannies mounted on the heatsink of output transistors, but it's not too late to change this if needed. So, what should I do?
 
small pcb

Hi Quattor,
Why not either plan to mount both. You can pull one away if you end up with a negative temperature coefficient. The other method would be to use a small pcb for you bias and mount it higher up. Circuit changes would be even easier then.
-Chris
 
Peranders - I didn't want to mess up with the original design that much. It performed so well on the simulator that I just had to built it the way it was given. Anyway, stripping it to one transistor is not that hard once I've sorted this one out 🙂...

Thanks guys!
 
Status
Not open for further replies.