Hi all,
My question is in this schematic for the power tube cathode resistor this 2001 edition is using 1.5K, while for SRPP schematic its using 880ohm, and the older model is 2X1.5k.
Is the 1.5K for the 2001 edition is meant for 45 tube or can I use it for 2A3 tubes?
45/2A3 means this circuit can be used for either 45 or 2A3 tube without any modification on the circuit?
Need some clarification I almost done the amp then notice the other value of cathode resistor on the other JE circuit
I intend to use 2A3 tube only so the 1.5K for cathode resistor is okay.
Thank you very much
Mac_G
My question is in this schematic for the power tube cathode resistor this 2001 edition is using 1.5K, while for SRPP schematic its using 880ohm, and the older model is 2X1.5k.
Is the 1.5K for the 2001 edition is meant for 45 tube or can I use it for 2A3 tubes?
45/2A3 means this circuit can be used for either 45 or 2A3 tube without any modification on the circuit?
Need some clarification I almost done the amp then notice the other value of cathode resistor on the other JE circuit
I intend to use 2A3 tube only so the 1.5K for cathode resistor is okay.
Thank you very much
Mac_G
Hi Here is the schematics, its also tap on 5K impedance, while other 2A3 is using 2.5k for the output transformer. and here's the link http://members.myactv.net/~je2a3/simple45.htm
thank you
thank you
Last edited:
Hi!
If You use 2A3 with recom. plate current 60 ma, the bias will be -90 v with res. 1,5 kohm.
This bias is very big /recom. is 45-55 v for best mode/. Cathode res. must be
800-1000 ohm.
If You use 2A3 with plate current 35-40 ma, 1,5 kohm is suitable, but sound
will be bad.
I think /I use in my 2A3 820 ohm Mills/ res. must be less 1 kohm.
1,5 kohm is for tube 45 with plate current 35-40 ma.
If You use 2A3 with recom. plate current 60 ma, the bias will be -90 v with res. 1,5 kohm.
This bias is very big /recom. is 45-55 v for best mode/. Cathode res. must be
800-1000 ohm.
If You use 2A3 with plate current 35-40 ma, 1,5 kohm is suitable, but sound
will be bad.
I think /I use in my 2A3 820 ohm Mills/ res. must be less 1 kohm.
1,5 kohm is for tube 45 with plate current 35-40 ma.
Thank you very I'm a newbie based on the circuit cathode voltage is 55V where it come from and how to compute it (cathode voltage).
based on 2A3 data sheet plate dissipation = 15W max
Some circuit use 880ohm but difficult to find I have a 820ohms but the Plate dissipation will be 55V/820 = 67ma
275V x 0.067A = 18.425W which is over the 2A3
max is t okay, if okay then I will
use it or is there need to do some modification on the circuit I intend to use 2A3 tub only. thank you
based on 2A3 data sheet plate dissipation = 15W max
Some circuit use 880ohm but difficult to find I have a 820ohms but the Plate dissipation will be 55V/820 = 67ma
275V x 0.067A = 18.425W which is over the 2A3
max is t okay, if okay then I will
use it or is there need to do some modification on the circuit I intend to use 2A3 tub only. thank you
- Status
- Not open for further replies.