SY,
You are correct! A ton of gain and the noise associated with it (hiss).
I left out resistors R6,R5, R12, and R13 from my 6SN7 Aikido.
Any sonic, or just protection differences?
You are correct! A ton of gain and the noise associated with it (hiss).
I left out resistors R6,R5, R12, and R13 from my 6SN7 Aikido.
Any sonic, or just protection differences?
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?
Exactly the way we did the earlier example, but using the datasheet for the 12AT7. But you will end up with a LOT of gain.
i have the 6922 also... but what will i do with my 6201s (aside from using 1 piece for my hf87 project)? 😀
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
my psu can only supply 250V for a 6922 -> 12SN7 Aikido, would this be a problem for the 12SN7? I would really like to use my existing tranny but if it would greatly affect the sound when a 300V B+ is used then I have no choice but to get a new tranny.
any suggestions?
regards
any suggestions?
regards
You have a lot of heater supply options. I think that the best one is two separate supplies for upper and lower heaters with the upper supply lifted off ground by 160V or so, the lower one by 10-20V or so.
300V is a bit high for ECC88; 200V would be better.
300V is a bit high for ECC88; 200V would be better.
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
burnedfingers
yes
absolutely
JojoD
i've tried 12AT7/ecc82 first
and it was way too much gain
why don't you use 6922 first
then 12AT7/ecc82 second
ecc82 makes a nice CF
one heater supply
you have it all
dave dove
yes
absolutely
JojoD
i've tried 12AT7/ecc82 first
and it was way too much gain
why don't you use 6922 first
then 12AT7/ecc82 second
ecc82 makes a nice CF
one heater supply
you have it all
dave dove
The 6922, and 6N1P were several of the 1st tube choices. The gain is less than what the 12AT7 would be and speaking from experience you don't want/need all that gain. I have tried higher Mu tubes only to be rewarded with extra noise/hiss/static.
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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