Hi all-
Do we have opinions on the use of 12AX7 as a cathode follower? Is there something perhaps more appropriate to use in the same socket? Thanks...
Do we have opinions on the use of 12AX7 as a cathode follower? Is there something perhaps more appropriate to use in the same socket? Thanks...
12AX7 has poor drive capability, a 12AU7 or 12AT7 would be more appropriate, but they have different enough characteristics that it won't simply drop in to replace it without circuit changes in most instances.
For what? Driving 500k pots? Driving 833 grids? Driving modern studio inputs?
Why ask? Wire it up. There's at least a dozen tube-types which will plug in and work "the same", see what suits you.
FWIW: in the 'audio' range, the AX7 may be the most used cathode follower in serious gear, going back to the K2-W opamp.
It's at the output of a freestanding phono stage and will drive the usual RCA inputs of the next box.
Happy to change passives around the socket to optimize, but I can't change to a different socket.
It's more or less based on Marantz Model 7 phono stage, which uses a 12AX7 for this. Thank you.
Happy to change passives around the socket to optimize, but I can't change to a different socket.
It's more or less based on Marantz Model 7 phono stage, which uses a 12AX7 for this. Thank you.
If it's good enough for Marantz ?
Use a 12AX7, they are well known and reliable. A 12AU7 is also good as is a 12AT7.
In your configuration, nothing needs to be changed, component value wise. It is not a gain stage.
Use a 12AX7, they are well known and reliable. A 12AU7 is also good as is a 12AT7.
In your configuration, nothing needs to be changed, component value wise. It is not a gain stage.
Hmmmm... I am no expert but my thinking is that an 12AX7 would be fine to drive a feedback network (say a 12AX7 gain stage direct coupled to a 12AX7 CF fed back to 1st stage grid) but if driving an external connection why not switch to a 12AT7 (with appropriate cathode resistor change) to give better drive in case you decide to use it to drive a solid state line amp?
One of my amps I designed with 12AX7's in mind, but changed out to 12AY7's - the result was a quieter background, yet still plenty of gain