they can be used to affect gain
but not at 100K
they have two purposes
the first is to protect the following valve
should you happen to pull one out
or due to failure
and the second is they reduce distortion
which is only noticeable when you put them in.....
i have tried it both ways
and there is a difference
dave dove
but not at 100K
they have two purposes
the first is to protect the following valve
should you happen to pull one out
or due to failure
and the second is they reduce distortion
which is only noticeable when you put them in.....
i have tried it both ways
and there is a difference
dave dove
Hi all, SY,
just got back and I want to continue my Aikido project. My plan is to use 12AT7/6201 in the input tube and 12SN7 in the output tube. SS rectified and regulated 300V B+.
I believe I should use SY's calculations for the output tube (6SN7) located in the first couple of pages of this thread.
How do I proceed with the 12AT7 input tube?
just got back and I want to continue my Aikido project. My plan is to use 12AT7/6201 in the input tube and 12SN7 in the output tube. SS rectified and regulated 300V B+.
I believe I should use SY's calculations for the output tube (6SN7) located in the first couple of pages of this thread.
How do I proceed with the 12AT7 input tube?
errr... 6922 heaters are 6.3 volts while 12sn7 are 12.6 volts.
should I series the 6922 then parallel them to 12sn7? or make separate 6.3V regs and 12.6 regs?
what's the best approach? safest? of course this heater supply should be lifted above ground, yes? assuming 300V b+ and about 150V between tube sections, must I lift them around 150V?
Thanks
JojoD
should I series the 6922 then parallel them to 12sn7? or make separate 6.3V regs and 12.6 regs?
what's the best approach? safest? of course this heater supply should be lifted above ground, yes? assuming 300V b+ and about 150V between tube sections, must I lift them around 150V?
Thanks
JojoD
SY,
what about the 12sn7? would it be fine as an output tube with 200V only? i'm a bit concerned and just making sure of things before I start drilling my chassis. it's a 6922 (input), 12SN7 (output) arrangement.
with the heater arrangement you posted, does that mean (for example) that I will use 1 6922 as lower tube only - meaning both triodes in that tubes be used for lower triodes, one for each channels? this means I have to provide separate 2X 6.3V and 2X 12.6V heaters then.
thank you very much for putting so much time with my questions.
JojoD
what about the 12sn7? would it be fine as an output tube with 200V only? i'm a bit concerned and just making sure of things before I start drilling my chassis. it's a 6922 (input), 12SN7 (output) arrangement.
with the heater arrangement you posted, does that mean (for example) that I will use 1 6922 as lower tube only - meaning both triodes in that tubes be used for lower triodes, one for each channels? this means I have to provide separate 2X 6.3V and 2X 12.6V heaters then.
thank you very much for putting so much time with my questions.
JojoD
SY,
I guess I better be using tubes that my psu can supply sufficient voltage than to just make ends meet. That way I won't be sacrificing my tubes operating voltages. Lesson learned - my octal Aikido should wait.
burnedfingers,
I was thinking of using a straight 6922 version since I have about 5 pairs of 6922s of different brands.
but when I read Dave's post about using my 12at7 as output tube that made me think again since I have both 6922 and 12at7.
you are right about the gain, even SY warned me of too much gain, I don't need too much gain so lesson learned - stick with low mu tubes.
help on resistor values for 6922/6DJ8 input -> 12AT7/6201 output configuration please.
I guess I better be using tubes that my psu can supply sufficient voltage than to just make ends meet. That way I won't be sacrificing my tubes operating voltages. Lesson learned - my octal Aikido should wait.
burnedfingers,
I was thinking of using a straight 6922 version since I have about 5 pairs of 6922s of different brands.
but when I read Dave's post about using my 12at7 as output tube that made me think again since I have both 6922 and 12at7.
you are right about the gain, even SY warned me of too much gain, I don't need too much gain so lesson learned - stick with low mu tubes.
help on resistor values for 6922/6DJ8 input -> 12AT7/6201 output configuration please.
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