kianbach said:...Plate resistor 10k
...Any suggestions/comments welcome.......
Take a little more for the plate resistor ... 47 kOhm (rp of the 6N7 in parallel is 11 kOhm).
Regards Andreas
AndreasS said:
Take a little more for the plate resistor ... 47 kOhm (rp of the 6N7 in parallel is 11 kOhm).
Regards Andreas
Won't this drop the B+ a bit much though?
What about the cathode resistors are they ok?
As my previous post I used 100k plate R and this dropped too much of the B+ voltage.
Well,according to my data book I should be getting -5v on the grid @3mA so I was thinking of running it with an 820 or 1k cathode R BUT with a 47k plate resistor this would drop over 200v from my B+ which is 290v .I was looking at dropping more in the region of 40 to 140V so as to run the valve at 150 - 250 v.My calculations bring a cathode R of 1666 ohms so I suppose a 1k5 would be ok yes?This gives about 3.3 mA.
This would mean a plate R to drop 140v of 42.5k so I suppose a pair of 82k in parallel connected to a 1k5 in series be ok.Any comments? Or am I flogging a dead horse and would be better off using a different valve?
This would mean a plate R to drop 140v of 42.5k so I suppose a pair of 82k in parallel connected to a 1k5 in series be ok.Any comments? Or am I flogging a dead horse and would be better off using a different valve?
6N7
6N7 has only one cathode.
6N7 has only one cathode.
IMO 6N7 is not a good driver for 2A3 , in fact finding a driver which can provide 90-100V swing from 300V is going to be difficult unless transformer coupling is used . Anyway , here's my suggestion using a 6SN7
cheers
316a
Hi!
The 6N7 works nicely as a driver for tubes like 45 or 2A3. However if fed from the same B+ voltage, the available swing with RC coupling will be very limited. RC coupled it would need more like 450V B+. In a 45 or 2A3 amp with common B+ between output stage and driver LC or transformercoupling is needed for the 6N7. Then it works really nice.
Plates and grids need to be tied together. Another nice touch: a 6J5 will drop in without any changes, even with the same socket wiring. This will prvide less gain and a lower impedance drive in the same environment.
Best regards
Thomas
The 6N7 works nicely as a driver for tubes like 45 or 2A3. However if fed from the same B+ voltage, the available swing with RC coupling will be very limited. RC coupled it would need more like 450V B+. In a 45 or 2A3 amp with common B+ between output stage and driver LC or transformercoupling is needed for the 6N7. Then it works really nice.
Plates and grids need to be tied together. Another nice touch: a 6J5 will drop in without any changes, even with the same socket wiring. This will prvide less gain and a lower impedance drive in the same environment.
Best regards
Thomas
How about a SRPP stage... http://ttradio.net/images/srpp.htm
Quote: The maximum non distorted output voltage swing is 134 Vpp from a 300 V B+ supply
Quote: The maximum non distorted output voltage swing is 134 Vpp from a 300 V B+ supply
6n7
Good idea, if you have more than one tube.
How about a SRPP stage... http://ttradio.net/images/srpp.htm
Quote: The maximum non distorted output voltage swing is 134 Vpp from a 300 V B+ supply
Good idea, if you have more than one tube.
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