Maybe we should call this the yellow light district...
Not sure if all of the bias leds for the 2A3 are red or yellow. There are incidentally jumbo red leds with vf of 1.9V with what I understand is typically slightly lower dynamic resistance than is the case with yellow leds, based on your results I would guess the yellow should be fine imo..
Glad to hear it is working well...
Not sure if all of the bias leds for the 2A3 are red or yellow. There are incidentally jumbo red leds with vf of 1.9V with what I understand is typically slightly lower dynamic resistance than is the case with yellow leds, based on your results I would guess the yellow should be fine imo..
Glad to hear it is working well...
Output @ 100Hz, 1 kHz, 10 kHz
Here are voltage traces of the output loaded with 8.2 ohm resistor
Upper traces are input 1V/div
Lower traces are output 5V/div
100Hz .........................1 kHz.............................10 kHz
Here are voltage traces of the output loaded with 8.2 ohm resistor
Upper traces are input 1V/div
Lower traces are output 5V/div
100Hz .........................1 kHz.............................10 kHz
Attachments
Artosalo and RajkoM made me come back to this project and do some tweaky-tweaky.
I am going to optimise driver stage operation point either
1. using BJT CCS, changing resistor values which set Ia current and adding heatsink to BF421 (TO-92)
2. use DN2540 cascode CCS if (1) will not work well.
You may find the discussion in here http://www.diyaudio.com/forums/tubes-valves/194358-e180f-v-ef184.html
Thanks RajkoM and Artosalo
PS. This exercise will help me design GM70 parafeed driver, I hope.
I am going to optimise driver stage operation point either
1. using BJT CCS, changing resistor values which set Ia current and adding heatsink to BF421 (TO-92)
2. use DN2540 cascode CCS if (1) will not work well.
You may find the discussion in here http://www.diyaudio.com/forums/tubes-valves/194358-e180f-v-ef184.html
Thanks RajkoM and Artosalo
PS. This exercise will help me design GM70 parafeed driver, I hope.
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