Transistor voltage and current gain

[armdnrdy]

I'm working on a BBD tester which inputs a 500Hz sine wave through the BBD.
The sine wave exits the BBD, travels through a rectifier (to convert to DC) to the base of a switching transistor. (simplified description)

When I bread boarded the whole circuit I encountered current loss after the BBD.
I also didn't factor in the voltage drop of transitioning to half wave rectified DC.

In BBD circuits it is common practice to include common collector amplifiers before and after the BBD (actually most include active Sallen-Key filters) to keep current loss in check.

So..in the testers application, I need to increase the current and the voltage after the BBD.
I drew up a rough idea which I need some input on:



Since I have a bias voltage entering and exiting the BBD, can I lose Q1 and Q2 bias resistors (R3,4, 6, 7) if I delete C2 and C3?
Or will that cause issues that I don't see?

[PRR]

Why do you use two emitter followers?

Why does Q2 have a collector resistor when there is no output from the collector?

[armdnrdy]

Oops!
Thanks for the reply,

I changed the order of the transistors in the drawing and messed it up!

I'll fix it and repost.

[armdnrdy]

Fixed and reposted.

I was wondering if there is a better way to bias the transistors.

The values shown are taken from examples found on the net.

[Fender3D]

In micmix dyna flanger, weren't Q4 and 5 used to increase output current?

[armdnrdy]

Hey Federico,

This is Wayne's description of those components.

"Q4, a dual transistor and Q5 provide a current mirror output to lower the SAD1024's distortion."

I would just emulate the pre and post filtering sections of a delay or flanger but I don't need all of the filtering. The BBD is only passing 500Hz instead of a range of frequencies. (guitar signal)

I want to try to keep this as simple as possible.

[armdnrdy]

I need to increase the current and voltage after the BBD and before D5 in this circuit: