Weekend SE 6GK6 project - and PSE 6DZ7s
Posted: Mon Aug 16, 2010 1:49 pm
What to do with two 6GK6s, two 6CG7s, two Edcor GXSE10-8-5Ks, a Hammond 272BX power trannie and 10X6X2 chassis, and a handful of small components... Bad knee keeping me kinda down, so rather than enjoying the nice summer weather outside, I decided to cobble this little puppy up, designing and building it "on the fly"... No NFB, naturally.
SRPP 6CG7 drivers, SE UL 6GK6s, and a surprisingly very good sounding amplifier resulted. Started Saturday afternoon, just finished it this morning (Aug 16, 2010) It's been playing about 5 hours, and the sound is really growing on me
The 272BX developed too high a B+ voltage (nearly 400VDC, so I used the otherwise unemployed 5V filament winding to buck the AC line voltage back to 115VAC, and the B+ came out at 380VDC, right where I wanted it.
I'm running the 6GK6s at 40 mA cathode current, this seems to fall right into the sweet spot, even though it's pushing the PD ratings a bit beyond the edge. In teh spirit of Tube Lab George, if the late isn't glowing cherry red, it isn't working hard enough So, I just pushed the edge of the envelope just a little, this time around.
/ed B
SRPP 6CG7 drivers, SE UL 6GK6s, and a surprisingly very good sounding amplifier resulted. Started Saturday afternoon, just finished it this morning (Aug 16, 2010) It's been playing about 5 hours, and the sound is really growing on me
The 272BX developed too high a B+ voltage (nearly 400VDC, so I used the otherwise unemployed 5V filament winding to buck the AC line voltage back to 115VAC, and the B+ came out at 380VDC, right where I wanted it.
I'm running the 6GK6s at 40 mA cathode current, this seems to fall right into the sweet spot, even though it's pushing the PD ratings a bit beyond the edge. In teh spirit of Tube Lab George, if the late isn't glowing cherry red, it isn't working hard enough So, I just pushed the edge of the envelope just a little, this time around.
/ed B