They're not that large, they just look big as the amp is so small. Russian silver mica 0.1uF in the coupling cap position. Sound a little better than the Wimas. Order a few on ebay and roll them in
Done!
High end audio amplifier. 42W per channel maximal power. Single ended (of course class A: SE amp can't work in any other class!).
GK-71 Soviet military output tubes. 12HL7 driver tubes (designed for color TVs frame grid, very linear pentodes). Voltages for G1, G2, G3, and driver are stabilized by MOSFET voltage regulators. DC for filament is derived by 150W SMPS, that's why the amp is so small. Proprietary schematic design, both stages pentode, with nested feedback loops. The result is, the sound is cleaner than from triodes, and output power is more than can be get from a pentode with no FB. Soft clipping, despite of the myth that feedbacks ruin the sound. 20 Hz - 50 KHz bandwidth before visible on oscillioscope roll-off.
I never heard a better amp!
PS: I had to convert pictures to 800x600: now the forum does not accept 2MB files.
High end audio amplifier. 42W per channel maximal power. Single ended (of course class A: SE amp can't work in any other class!).
GK-71 Soviet military output tubes. 12HL7 driver tubes (designed for color TVs frame grid, very linear pentodes). Voltages for G1, G2, G3, and driver are stabilized by MOSFET voltage regulators. DC for filament is derived by 150W SMPS, that's why the amp is so small. Proprietary schematic design, both stages pentode, with nested feedback loops. The result is, the sound is cleaner than from triodes, and output power is more than can be get from a pentode with no FB. Soft clipping, despite of the myth that feedbacks ruin the sound. 20 Hz - 50 KHz bandwidth before visible on oscillioscope roll-off.
I never heard a better amp!
PS: I had to convert pictures to 800x600: now the forum does not accept 2MB files.
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No mosfets.. Fixed bias, not filament bias - I'm not a fan at high voltages.
There are 25V LT1083 based pre-regulators in the power supply chassis which each dissipate around 15W, and each Coleman regulator also dissipates 15W.
Each tube dissipates a total of 180W worst case, and each amplifier consumes about 235W. All linear, no switchers.
The amps are monoblocks with outboard supplies, and heat up my listening room rather significantly which is fine for about 9 months of the year.
There are 25V LT1083 based pre-regulators in the power supply chassis which each dissipate around 15W, and each Coleman regulator also dissipates 15W.
Each tube dissipates a total of 180W worst case, and each amplifier consumes about 235W. All linear, no switchers.
The amps are monoblocks with outboard supplies, and heat up my listening room rather significantly which is fine for about 9 months of the year.
No. Why?
I have a couple of 20 Ohm resistors shunted by 10.000 uF caps across the filaments (gray caps to the left, white resistors under them).
Yes, +/- 10V on the ends of cathode, but I think it is the lesser evil than intermods with harmonics of high pitch sounds.
The difference is, pentode VS triode. Nested feedbacks, MOSFET grid driver.
Testing the amp with 4 Ohm speakers... It drives them clean and loud! Can't deliver more than 20W on them, though...
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Yes!
The sound was so real, sphincters can unleash. Legacy speakers are awesome!
Careful, "Sphincters relax at death, often releasing fluids".