I agree with Dekay. Although it is not recommended to substitute a 12AT7 for a 12AX7 a 5751 is simply a special (industrial) type of 12AX7 with lower gain and a slightly higher heater current. Amplification factor of the 12AX7 is 100 where the 5751 is 70. I have both NOS 12AT7 and 5751 tubes in stock if you need them but would not recommend the 12AT7 in this case.
Tube subtitutions 12AT7 for 12AX7
My old ARC SP6-B sounds swell with my phono,
but has way too much gain for my CD players.
To get normal volume levels,
I barely adjust the gain past 9 o'clock (3 clicks).
With the stepped gain, this leaves no room for
fine volume adjusments.
I would like to reduce the gain by substituting
the 12AX7 tubes (in the line stage portion only)
for 12AT7's. There is some discussion of this
at www.thetubestore.com, but more from a guitar amp
point of view, than audiophile amps.
Does anyone have any experience with this sort of thing?
Am I gonna wreck the preamp doing this?
but has way too much gain for my CD players.
To get normal volume levels,
I barely adjust the gain past 9 o'clock (3 clicks).
With the stepped gain, this leaves no room for
fine volume adjusments.
I would like to reduce the gain by substituting
the 12AX7 tubes (in the line stage portion only)
for 12AT7's. There is some discussion of this
at www.thetubestore.com, but more from a guitar amp
point of view, than audiophile amps.
Does anyone have any experience with this sort of thing?
Am I gonna wreck the preamp doing this?