Death of Gain Clone

[widowmaker]

coming soon - pdf file of PCB (last version)

for sale:


price for 2 boards (without components)+paper sheet with component location view - 20 EUR (without shipping taxes).

widowmaker@mail.bg

[peranders]

Is it possible to get thermal stability without any emitter resistors at the output stage?

[widowmaker]

It is possible, offset is floating approx. +/- 20-30mV
Current source for IRF620 is unstable "upside down", wich compensate instability of diff. input stage...
Carefully look at schematic - there are transistors after shunt regulator 431, and "strong point" for 620 is emmiter of CS for Diff. stage.
I have score of amps, no problems with offset.

[richie00boy]

I think he means stability of bias current, not output DC offset.

[peranders]

Yes, I mean the stability of the bias current with different temperatures.

[widowmaker]

Bias current for 9610 is higher than necessary (in this case), so unstability is not much important value...

Is it possible to get thermal stability without any emitter resistors at the output stage?

Output transistors ("dumpers") are near class B - approx. 320-350mV Ube (depending on temperature range).
This is a feedforward error correction amp.
Dumpers originally working without idle current.

[kalmara]

Kolega, haresva mi usilvatelq - slushah go v edin priqtel, no iskam samo da otbeleja...na kartinkata za izhodqshtite droseli pishe (0.86 with lack isolation) ... lack na angliiski oznachava lipsa na neshto i edva li horata sa razbrali kakvo se ima vpredvid, spored men po-dobre za lakovata izolaciq e da se izpolzva varnish. S netyrpenie chakame pdf-a na platkata, za da izprobvame i pravotokovata versiq.

[tiefbassuebertr]

This is also an interesting approach (unfortunately only to find only by chance regarded the therm "Death of Gainclone" insted the actually term for this topology), especially for translate into a CSPP topology (Circlotron).
I will study this thread next time.
In this case also this thread could be of interest:
Chip Amp based on the topologies from Yamaha MX-10000 and Quad 405

Here an inspiration for a solution for an enclosure/cabinet
Synergy - LM3875 Gainclone Amplifier (Chip Amp)

[ontoaba]

The GC case is really beautiful, small and funny.

[ljm_ljm]

CURRENT DUMPING ？
I VERY LIKE。
BUT,MOSFET TO DARLINGTON ，I believe there will be a better force。