Finally got enough other (non-tube, non-electronics) projects out of the way such that SWMBO is allowing expenditure and effort in smoke making.
I got a bunch of VT61A HF triodes a while back - very old WWII surplus. These are a cute-as Mickey Mouse tube used as finals in the radio sets in Spitfire aircraft. Who could resist? Closest data I could get was RK34 which is electrically identical, different base.
So the plan is for a 'sl7 LTP buffered by Pete's clever little circuit and swinging the required 100v p-p into the VT61A driving it as close to AB2 as I can get without sounding horrific.
OPTs are probably going to be Edcor 15w open frame jobs with power coming from Edcor as well. Optional OPTs are some nice vintage NOS 8k:8 units built to go into high end local EL84 pp designs.
The design goals are stringently non-audiophile. Sure, it has to sound acceptable but the main goal is something looking cool (shallow Hal is me) in a steam-punkish sort of way, not the standard path EL84, with an interesting mix of old and new-ish tech.
A very standard design kwila wood frame topped with an aluminium plate is the chassis.
Speakers are a very simple early '70s vented box design with paired 16 ohm 8 inch drivers in parallel in each box. Not at all peaky or hard to drive, but also not SOTA.
Source is a Sumsung HDTV, processing (badly) DVD/CD, Spotify from a no-name Android tablet via HDMI, and a mix of mp3-esque players. I am going to be all rash and assume standard 2v source output. Eventually a pre-amp (likely a simple versions of SY's Heretical) will do front end duties and liberate me from the TV as preamp.
We'll forget about the turntable atm since that just complicates things further.
Comments and advice encouraged as we go - this may take some time so sit back and don't hold your breath...
I got a bunch of VT61A HF triodes a while back - very old WWII surplus. These are a cute-as Mickey Mouse tube used as finals in the radio sets in Spitfire aircraft. Who could resist? Closest data I could get was RK34 which is electrically identical, different base.
So the plan is for a 'sl7 LTP buffered by Pete's clever little circuit and swinging the required 100v p-p into the VT61A driving it as close to AB2 as I can get without sounding horrific.
OPTs are probably going to be Edcor 15w open frame jobs with power coming from Edcor as well. Optional OPTs are some nice vintage NOS 8k:8 units built to go into high end local EL84 pp designs.
The design goals are stringently non-audiophile. Sure, it has to sound acceptable but the main goal is something looking cool (shallow Hal is me) in a steam-punkish sort of way, not the standard path EL84, with an interesting mix of old and new-ish tech.
A very standard design kwila wood frame topped with an aluminium plate is the chassis.
Speakers are a very simple early '70s vented box design with paired 16 ohm 8 inch drivers in parallel in each box. Not at all peaky or hard to drive, but also not SOTA.
Source is a Sumsung HDTV, processing (badly) DVD/CD, Spotify from a no-name Android tablet via HDMI, and a mix of mp3-esque players. I am going to be all rash and assume standard 2v source output. Eventually a pre-amp (likely a simple versions of SY's Heretical) will do front end duties and liberate me from the TV as preamp.
We'll forget about the turntable atm since that just complicates things further.
Comments and advice encouraged as we go - this may take some time so sit back and don't hold your breath...
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