Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: W5FH on August 24, 2022, 08:59:41 am
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Out of curiosity here -
I did a search on this site for any info on this tube but found none. I would imagine that someone out there involved in audio work has experimented with the TungSol TS-272. It is a 9 pin dual triode very similar in appearance to the 12AX7. The two differ in that the TS-272 has:
1. A 6.3 volt filament that is between pins 4 and 5.
2. An internal shield (between triode sections) connected to pin 9.
Not sure if the internal shield would be of any value to audio work or maybe even detrimental??
I tested one years ago on my TV-7 and it read pretty close in transconductance to a 12AX7 using 12AX7 settings (allowing for filament differences). In my Ham radio hobby over the years I have parted out much military electronics and have seen only one piece of equipment that used that tube (of which I cannot recall model number). However the tube seems to more frequently than expected show up in surplus finds and I have some in my stock. I wish to experiment with them one day but thought I would put out a query. Thank you.