i mean - this is very strange - 100uF is not enough as a coupling capacitor...
when i was using only a buffer (without the tube part) the frequency range was perfectly o.k.... now.. it is not enough - what is happening there???
it seems like the input resistance of the buffer is a lot lower than it should be......
???
ohhh... btw - i just remebered..... i have a capacitor over a cathode resistor of the tube - it is 220uF capacitor - i have to check if that one is big enough...
when i was using only a buffer (without the tube part) the frequency range was perfectly o.k.... now.. it is not enough - what is happening there???
it seems like the input resistance of the buffer is a lot lower than it should be......
???
ohhh... btw - i just remebered..... i have a capacitor over a cathode resistor of the tube - it is 220uF capacitor - i have to check if that one is big enough...
oh yes... it was sooo dead....
buffer was dead - i assume that the tube burned the mosfet because i didn't put any zener diodes between gate and source... idiot....
anyway.. i tried 12B4 part alone .. it drives the headphones like a charm - no problem ... 20mA, Ug=10V, Up=106V.... perfect... sound is powerfull and detailed... very clear... i will remove the buffer for now and make it with 12B4 only.... it works nice....
buffer was dead - i assume that the tube burned the mosfet because i didn't put any zener diodes between gate and source... idiot....
anyway.. i tried 12B4 part alone .. it drives the headphones like a charm - no problem ... 20mA, Ug=10V, Up=106V.... perfect... sound is powerfull and detailed... very clear... i will remove the buffer for now and make it with 12B4 only.... it works nice....
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.