NoGNFB integrated amp with Ge transistors at output

[VladimirK]

Go with DSS16, seems to be a good choice.
Ge diodes that are available still are
D302 (1A, 200V)
D303 (3A, 150V)
D304 (5A, 150V)
D305 (10A, 50V)
Also one could use Ge power transistors as diodes (base and collector shorted)

I just had a look of what I have from Ge diodes, and could offer 16pcs of D304 (as one lot). We could discuss this subject via private messages.

 

[danielwritesbac]

Negative feedback can be excellent as a very last step.
When it is not abused, that is when it can be used for a quality improvement, but only then.
That is a matter of assumption and reliance, so kudos if you didn't.

 

[jps1964]

Hello Vladimir,

good news for the diode. Do you have a datasheet?

Regards,
Jean-Paul

 

[VladimirK]

Hello Vladimir,

good news for the diode. Do you have a datasheet?

Regards,
Jean-Paul

Electrical parameters
Continuous forward voltage at Uf = If.max, not more:
at T = 25 ° C:
D302, D304 0.25V
D303, D305 0.3V
Average reverse current at Urev.i = Urev.i.max, not more:
at T = 25 ° C:
D302 0.8 mA
D303 1 mA
D304 2 mA
D305 2.5 mA
at T = 70 ° C:
D302 3 mA
D303 4 mA
D304 10mA
D305 20mA
Limit operational data
The peak reverse voltage:
at T = -60 ... + 25 ° C:
D302 200
D303 150 V
D304 100 V
D305 50
at T = 40 ° C:
D302 150 V
D303 140
D304 100 V
D305 50
at T = 50 ° C:
D302, D303 120
D304 100 V
D305 50
at T = 60 ° C:
D302, D303 90 V
D304 70 V
D305 50
at T = 70 ° C: 50
Average forward current:
at T = -60 ... + 25 ° C:
D302 1A
D303 3 A
D304 5 A
D305 10A
at T = 40 ° C:
D302 1A
D303 3 A
D304 4A
D305 8 A
at T = 50 ° C:
D302 1A
D303 2.5 A
D304 3 A
D305 6.5 A
at T = 60 ° C:
D302 0.9 A
D303 2 A
D304 2.5 A
D305 5 A
at T = 70 ° C:
D302 0.8 A
D303 1.5 A
D304 1.8 A
D305 3 A
Average forward current overload factor within 0.5 seconds:
D302 4 If.av.max
D303 1.5 If.av.max
D304 2.5 If.av.max
D305 2 If.av.max
Frequency without reducing of electric modes 5 kHz
Ambient temperature -60 ° C ... + Tc = 80 ° C

 

[jps1964]

... two Vladimir´s amp in 3U enclosure and Vincent´s LDR attenuator...

Hello Vladimir,

what are the requirements for the transformer?

Regards,
Jean-Paul

 

[VladimirK]

... two Vladimir´s amp in 3U enclosure and Vincent´s LDR attenuator...

Hello Vladimir,

what are the requirements for the transformer?

Regards,
Jean-Paul

For class A applications, I would prefer, that the total power consumption would be within 25-35% of the rated power of transformer. If say 36V x 3A = 108W are consumed by both channels, we could get it roughly with 0,25-0,32kW toroidal trafo, designed with max magnetic inductance value around 0,8-1,0 T.