Parts and tubes have overfilled basement shelves and I was "ordered" by my better half to clean up....
The driver and output stages are built with parts I found while I slaved.....
Psu was made for a 50 se amplifier some years ago. 394a-lclc, Dave Slagle's lc modules feeding Rod Colemans filament regulators. The high voltage is way to high for the driver and output tubes, so I chose to drop the excess adding two simple shunt regulators.
The SFR E130 is a really nice tube. Pretty much similar to the rs 242, but lower internal resistance. Driving it into a2 yields just below 4W.
I had some concerns that these amplifiers would lack power to drive my speakers properly, but for daily listening they are more than powerful enough. The attached measurement is taken at normal listening level. In the middle a Linestage with VT-25 (separate psu not visible). It can be configured as only AVC (Dave Slagle/Bent audio modules) or 4:1 or 2:1 stepdown.
The driver and output stages are built with parts I found while I slaved.....
Psu was made for a 50 se amplifier some years ago. 394a-lclc, Dave Slagle's lc modules feeding Rod Colemans filament regulators. The high voltage is way to high for the driver and output tubes, so I chose to drop the excess adding two simple shunt regulators.
The SFR E130 is a really nice tube. Pretty much similar to the rs 242, but lower internal resistance. Driving it into a2 yields just below 4W.
I had some concerns that these amplifiers would lack power to drive my speakers properly, but for daily listening they are more than powerful enough. The attached measurement is taken at normal listening level. In the middle a Linestage with VT-25 (separate psu not visible). It can be configured as only AVC (Dave Slagle/Bent audio modules) or 4:1 or 2:1 stepdown.
