117v heater tube 117n7

[AtomiKM]

i ran a cross this on an ee site does this have any real place in audio does anybody know. seems kind of cool to me eliminating pt.
here is the link
http://www.du.edu/~etuttle/electron/elect27.htm#117
also here is the circuit he mentions

[leadbelly]

I don't understand how this same issue gets posted anew each week. Do not build a tube project wired directly to the mains, without a power transformer or isolation transformer. To take that risk just to avoid paying $10-15 for an isolation transformer is beyond me!

[AtomiKM]

not that i would ever actually have the balls to build the damn thing javascript:smilie('')
Big Grinbut i had just come across it and had never seen such a concept. i guess i should read more of this stuff e

[Miles Prower]

Originally posted by AtomiKM
i ran a cross this on an ee site does this have any real place in audio does anybody know. seems kind of cool to me eliminating pt.
here is the link
http://www.du.edu/~etuttle/electron/elect27.htm#117
also here is the circuit he mentions

Really cheap record players (like those you give to kids to keep them away from the good stuff) used amplifiers just like that.

Expect Lo-Fi operation: lots of hum from the high voltage heaters and typically poor filtering of the DC rail, no gNFB to tame pentode nastiness (and it's probably a really nasty pentode anyway) very inadequate output xfmr.

It was never designed to sound good, just to be dirt cheap to manufacture. For the cost of making that thing, you can get some chip amps that'll sound far better. Also, there won't be any experiences due to the lack of isolation from the AC mains.