JJman
Member
- Messages
- 994
In my homebrew Im using a LTPI to drive 2- 6v6 tubes in PP. They are cathode biased running AB at 12watts idle each. The plates are at 350VDC. Im wondering about the grid stoppers and if they are adequate at 1.5k. I sometimes think Im hearing a bad distortion in addition to the good distortion. No doubt the PI is driving them very hard. The PI doesnt clip on its own until after the output is clipping. I recently added NFB but I read that this can actually increase the chance of blocking distortion.
http://www.aikenamps.com/BlockingDistortion.html
http://www.freewebs.com/valvewizard/gridstopper.html
I definitely see crossover distortion on the speaker output when driven past the onset of the output clipping, but is that normal? (I once read that it is.) I understand the clamping that happens but Im not clear on whether the grid stoppers curtail clamping. Do they?
I have a signal generator and scope. Can blocking distortion be recognized on a scope? Is the crossover distortion, thats caused by extreme clamping, the same thing as blocking distortion?
I could throw 10k resistors on the grids as a test but Id like to fully understand 1st.
http://www.aikenamps.com/BlockingDistortion.html
http://www.freewebs.com/valvewizard/gridstopper.html
I definitely see crossover distortion on the speaker output when driven past the onset of the output clipping, but is that normal? (I once read that it is.) I understand the clamping that happens but Im not clear on whether the grid stoppers curtail clamping. Do they?
I have a signal generator and scope. Can blocking distortion be recognized on a scope? Is the crossover distortion, thats caused by extreme clamping, the same thing as blocking distortion?
I could throw 10k resistors on the grids as a test but Id like to fully understand 1st.