Wow!!! A wonderful preamplifier module!

[fotios]

This general module, it can be used as Line or C.D. or Phono input, or as Line driver or as Buffer with some interchanges of the passive elements that contains; and for making filters in electronic X-overs. He is absolutely made with discrete devices, thus it can operate with a high level supply (in this case with +/- 26 Volts) with the benefits it offers this. For example it can drive a power amplifier even if it has Zin 1ÊÙ! And with unbalanced signal cables of big length (over 5 meters) because it masking the noise (don’t forget S/N ratio!) with enough dB and without loses due to extremely wide output signal and the ultra low Zout. Moreover the output is preloaded with an appropriate voltage divider to reduce the signal width in order it is avoided an overdrive of the next stage. Because a picture deserves thousand words, i quote below a photo of the trial module and some characteristic oscilograms.

[fotios]

1. Tilt of a 10 Hz square 6Vpp it is only 0,64V from the leading to trailing edge!! What an incredible damping!

[fotios]

2. Tilt of a 100 Hz square 6Vpp it is only 0,12V.

[fotios]

3. Rise time of a 10 KHz square 6Vpp it is only 0,72 ìsec!! What an incredible speed!

[fotios]

4. Rise time of a 100 KHz square 5Vpp it is only 1,7 ìsec!!

[fotios]

5. Rise time of a 100 KHz square 6Vpp it is only 1,97 ìsec.

[janneman]

Originally posted by fotios
2. Tilt of a 100 Hz square 6Vpp it is only 0,12V.

If you want to do advertising, at least know what you are talking about. The tilt of the square wave says nothing of the damping but shows that you either have capacitive in/out coupling or capacitive feedback coupling. It shows you the limit of lf response.

Jan Didden

[janneman]

Originally posted by fotios
3. Rise time of a 10 KHz square 6Vpp it is only 0,72 ìsec!! What an incredible speed!

Originally posted by fotios
4. Rise time of a 100 KHz square 5Vpp it is only 1,7 ìsec!!

This is less than 3V/uSec! Incredibly slow!

Jan Didden

[Netlist]

In counterbalance, the PCB looks cute.
Care to post the schematic?

/Hugo

[lineup]

Originally posted by Netlist

In counterbalance, the PCB looks cute.
Care to post the schematic?

/Hugo

Good work, fotios!!! .... Hellas, Ellas, Ellada (greece)

I am interesting see your schematic, too.
Post please


I like discrete Line Preamplifiers & Buffers.
Much more fun to construct, than using those deadly boring op-amps chips.
( maybe we should call those
BLACK CHIP = Black Sheep
)

If IC chips was better,
then Mr John Curl, Nelson Pass and Hugh AKSA Dean
and me lineup
wouldn't bother to design:
discrete amplifiers ... with transistors!


Welcome fotios, my southern European friend
... to our transistor amplifiers design GROUP


Looking forward to more info.
Regards
lineup
Lineup Discrete Audio Lab