Bah, 6SL7 honestly doesn't give a damn what load you put on it. You could give it RL = Rp and it would only give 1% THD at high levels (i.e., maybe 30V; max. output might be 100Vp-p at 7% THD in this condition.)
If only they had 100 times the plate current, y'all would be hording those bastages instead of anything with the numbers and letter "300B" on it!
Tim
If only they had 100 times the plate current, y'all would be hording those bastages instead of anything with the numbers and letter "300B" on it!
Tim
Here's a link to the data sheet with the appropriate curves:
http://frank.pocnet.net/sheets/093/6/6SL7GT.pdf
Frank's Tube Pages ought to be in the running for a Nobel Prize.
In any case, there's a nifty little chart showing nice ways to run the tube for different plate voltages and gains, with info on how much you can swing for each set of suggested values. Your proposed plate resistor (80K) could work, but it's really a bit too low to get good distortion and output performance. Drawing up a load line for a 150K plate resistor, assuming you can get 300V of B+, you've got a pretty linear setup if you run about 1-1.1 ma current. That requires a grid-cathode voltage of 1.5V, which you can achieve with a 1.5K resistor. The distortion when swinging 50 volts up and down looks miniscule, and there's more swing capability than that.
http://frank.pocnet.net/sheets/093/6/6SL7GT.pdf
Frank's Tube Pages ought to be in the running for a Nobel Prize.
In any case, there's a nifty little chart showing nice ways to run the tube for different plate voltages and gains, with info on how much you can swing for each set of suggested values. Your proposed plate resistor (80K) could work, but it's really a bit too low to get good distortion and output performance. Drawing up a load line for a 150K plate resistor, assuming you can get 300V of B+, you've got a pretty linear setup if you run about 1-1.1 ma current. That requires a grid-cathode voltage of 1.5V, which you can achieve with a 1.5K resistor. The distortion when swinging 50 volts up and down looks miniscule, and there's more swing capability than that.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.