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D3a pentode as driver? History of this tube?

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#82
Yes sometimes the russian tubes are notreally the best. If you look for the best you have to look for the military ones. They are allways good.
I recently build a line amp with Siemens D3a. Running at 150V and 20mA into Lundahl 1660 4:1 Line Driver. Sound was nice as its normal with this tube.
I think its really worth the price ( I paid 16 Euros ).
I hope this thread goes on because its a great tube.
Greetings
Hilmar
 
#84
The problem I see with the D3A is the low g-k voltage, you never really get a 70x gain because you end up in a positive grid when you are pushing for the desired overall amp gain. 6e6p in most applications gives more ultimate power.

Its great for amplifying low level signals like in a DAC or phono preamp.
 
#85
barretter said:
The joke in Fawlty Towers was not about Poland, it was about the obsession of a certain kind of British person with the Germans and the Second World War. You probably have to be British to appreciate how funny the line is.
Lots of people were invading these islands in the period you mention and I have no reason to doubt your history. I was just rather surprised that such a long dormant thread had been re-opened with such a comment.
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I think we share the same sense of humour - I love John Cleese and used to watch The Fawlty Tower with great pleasure. And you are probably right not all British jokes make Poles laugh, however not because they are not funny, but we do not know the exact context. And the opposite is also true. Perhaps I should put my comment in "". I actually referred to Polish "heroes" who had thrown Molotov coctails at Russian embassy in Warsaw on Nov, 11th (Independence Day) and then had been proud of it.
I admit reopening the thread with such comment is surprising, however I read it looking for information about drivers for my GM70 parafeed amp. And found the quote... Eh.

Excuse me invoking politics. I did not have bad intentions.
Good thing is the thread is brought to live.

Pawel
 
#86
Surely that D3a is wired triode not pentode ?

Richard Ellis said:
I ran across this schematic of a parallel 2A3 with a D3A as a driver (Redrawn from Audiodesignguide.com)....I can't seem to find any info on this tube!
Most of the more "common" tubes have entire colorful histories associated with their development. This D3A I can't find anything..what was it used for , when did it first come out et al.
_______________________________________Rick..........
Click to expand...

Sorry for resurrecting, but I tripped across this schematic while looking for how to select resistor value between g2 and anode on D3a. It says D3a pentode, but the diagram shows triode mode ? g2 direct connected to anode ? Am I right ?

The schematic is in post 1 but the thread went off to discuss alternative russian valves, group buys and Fawlty Towers ...
 
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