Not quite in the league of the "power" users on this forum... 
.
But I needed an amp for my desktop computer bookshelf speakers, and I needed my first "training wheels" tube project (to amongst others test the SPICE tube models), so the "Baby Bloks" were born.
Eejit (on this forum) suggested I try the sound of the EL84 as part of the tube listening & learning experience so that was the choice of output tube.
Since it is a desktop, not much output power is needed.
SPICE simulation was within a few % on dc bias and circuit gain using "fresh" tube models.
The most difficult component to model is the OPT. The schematic shows my attempt for the Hammond OPT.
Photo shows the LH amp; the RH amp is a mirror image. Power input is 262V and 6.3V dc fed from an (off-board) smps supply in a separate small box.
With the 6SN7 common cathode bootstrapped to the cathode follower this gives very low distortion for the input stage. So the sound you should hear is mostly influenced by EL84 / Output Transformer (Karel Mar's C Core) & speaker combination, which sounds pretty good IMHO.
.But I needed an amp for my desktop computer bookshelf speakers, and I needed my first "training wheels" tube project (to amongst others test the SPICE tube models), so the "Baby Bloks" were born.
Eejit (on this forum) suggested I try the sound of the EL84 as part of the tube listening & learning experience so that was the choice of output tube.
Since it is a desktop, not much output power is needed.
SPICE simulation was within a few % on dc bias and circuit gain using "fresh" tube models.
The most difficult component to model is the OPT. The schematic shows my attempt for the Hammond OPT.
Photo shows the LH amp; the RH amp is a mirror image. Power input is 262V and 6.3V dc fed from an (off-board) smps supply in a separate small box.
With the 6SN7 common cathode bootstrapped to the cathode follower this gives very low distortion for the input stage. So the sound you should hear is mostly influenced by EL84 / Output Transformer (Karel Mar's C Core) & speaker combination, which sounds pretty good IMHO.
