This is like asking for some bad **** to happen right? haha I can tell, got some JJ 6v6s doing this right now sounds ******* killer, but man thinking ***** about to blow up
Last edited:
Hi Guys
Are you asking if resistors can be placed in series and/or parallel with an OT primary?
Yes they can.
Is it useful?
High-value Rs in parallel with the OT primary help to tether the plates if the load opens. It is a a benign way to tame potential transients and oscillation, as well.
If you are misreading the 6V6 data and think that the amp you have is putting too much voltage on the plate, and believe that series-Rs will save the tube, then you are mistaken. 6V6s can easily work from 500V+ rails since they were also used in TV circuits and had to withstand 1500V pulses. Tube ratings changed over night back in the 1950s, but many data sheets did not get changed. The original ratings tried to second-guess variations in the user's circuitry in addition to covering the variations of the tube maker's production.
Where more series resistance is a good thing is in the screen circuit. Screen-stops should be 1k minimum for each tube - not to drop voltage but to control the tube's impedance and protect it from failure during clipping. See TUT.
Have fun
Are you asking if resistors can be placed in series and/or parallel with an OT primary?
Yes they can.
Is it useful?
High-value Rs in parallel with the OT primary help to tether the plates if the load opens. It is a a benign way to tame potential transients and oscillation, as well.
If you are misreading the 6V6 data and think that the amp you have is putting too much voltage on the plate, and believe that series-Rs will save the tube, then you are mistaken. 6V6s can easily work from 500V+ rails since they were also used in TV circuits and had to withstand 1500V pulses. Tube ratings changed over night back in the 1950s, but many data sheets did not get changed. The original ratings tried to second-guess variations in the user's circuitry in addition to covering the variations of the tube maker's production.
Where more series resistance is a good thing is in the screen circuit. Screen-stops should be 1k minimum for each tube - not to drop voltage but to control the tube's impedance and protect it from failure during clipping. See TUT.
Have fun
method of attenuation as well, yeah oscillation's etc need some more small caps to use for snubber for that ...and no I'm not worried one bit about the plate voltage its the screen that you need to be worried about....still using 470Rs 5w for screens probably will go up to 1k maybe.Thanks for the response and info though.
Just Saying Don't expect them to last long...some old GE/Ken-rads died pretty quick that I had.
Just Saying Don't expect them to last long...some old GE/Ken-rads died pretty quick that I had.
Last edited:
Hi Guys
It is a poor approach for attenuating the output.
With 1k or higher screen-stops you do not have to worry about amps eating tubes.
Have fun
It is a poor approach for attenuating the output.
With 1k or higher screen-stops you do not have to worry about amps eating tubes.
Have fun
- Status
- Not open for further replies.