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any ideas with this?
I know one mans junk is anothers treasure, & some would say why bother- but,.. and being that the current living situation does not allow me to crank a bigun up I have to diddle with small ampsthe wattage is suppose to be around 5-8 watts
http://www.freeinfosociety.com/electronics/schematics/audio/kay703.pdf uses
36AM3 -recto
60FX5 -power
18GD6A -preamp
this one though uses a different tube lineup - same sort of amp12au6, 50L6-power,35Z5-recto--- is even lower around 1 watt
different schemhttp://www.schematicheaven.com/bargainbin/kay703.pdf
I know that I will have to use a isolation tranny& will get a GFCI plug as well
but I was wondering
1) how can I get more wattage-- around 10-15 watts
2) which power tube 7 pin or 12 pin could I use to achive this?
a 6JN6A looks interesting @ 17.5 W
I just wanted a bit more out of itany suggestions?
Follow Ups:
You are playing with fire... I got burned one day when I touched the B+ rail on a Carver PM1.5... @100VDC built to deliver gobs of current. I still vividly remember the sensation, although that's nothing compared to the hazard you're exposing yourself to. Link below.
Hey Delbro,As you seem committed to using an isolation tranny I won't browbeat you - just don't under rate the seriousness of the issue
!
In general you can get the most power from output tubes designed for line connected equipment - with a bit more THD - by running them at about 2X USA line voltage (about 250 VDC or less) on the plates. While the tube manuals don't necessarily recommend this there were sufficient examples from engineering and hobbiest magazines in the 1950s-60s to demonstrate the feasibility - but be sure to run the screen grids within specs or the bottles will meltdown.In 1960 the 7695 was specifically designed as a high dissipation audio output tube for line connected audio - for HiFi no less - with 16W plate dissipation. The 7695 has a 50V heater and there was also the 7754 version with a 6.3 volt heater but I've never seen one. I've used these bottles to make a couple of experimental guitar amps that ran the heaters directly off the mains while isolating the B+ supply with a tranny (tubes specifically designed for line connected equipment have quite good heater-to-cathode breakdown ratings so I'm entirely comfortable using a smaller isolation tranny for the B+ only - the heaters aren't referenced to ground nor to a positive supply).
I wouldn't bother with horizontal output tubes such as the 6JN6 if you can find the 7695s. And the GFCI won't protect you if the same amount of current that flows "from" (yeah, AC I know) the "live" lead returns "back" through the neutral conductor - even if it's flowing through your body. These devices only sense an imbalance and balanced currents can still kill thus making the isolation tranny necessary.
PS,
I am stuck with this
You can quite easily toss it out with the rest of your trash & by doing so live another decade or more. An isolation transformer or GFI will not protect you with this circut as both can pass sufficient lethal current. Search for *My Experience* authored by me in this forum catagory recently.
I had never read your post "My Experience". Thank you for sharing your story... I'm glad you made it, and I hope that you fully recover from your injuries.
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