This project has for the most part been abandoned since the result was not fully worth the investment. However, if someone is interested in the single amp I detailed here they can message me for details.
However, it did bring about a new preamp/ headphone amp idea. This one is a hybrid, however and uses a one 6SN7 tube per channel for the driver and an IRF610 Mosfet wired as a source follower for the output and has a very similar overall topology to the Natayo.
Some more details about it:
It is a fully single ended design and has very wide audio bandwidth (greater than 20hz-50khz@+/-1<db) since there are no output transformers
I used an Alps Blue Velvet potentiometer for the volume control and all Neutrik parts for the input and output connectors
One pair of RCA inputs, one pair of RCA outputs and a 1/4" SE jack headphone output
Output power is about 2.5W into 32 ohms and can drive very long preamp cables if needed
This amp is pictured with a Padauk chassis but will actually be shipping with a walnut chassis.
I made a few top plates exactly likes this but I plan on making a couple changes to it such as adding an output selector switch for the headphones and RCA outputs and also swapping the placement of the volume knob and headphone output. I plan to sell the new headphone amp (with mentioned changes) for 975USD with free shipping in North America.
However I would like to clear out the couple top plates I have left for this current design pictured before ordering new top plates and making a page on my website.
If anyone would like one made with the pictured top plate I will charge 850USD and also include free shipping within North America. I only have two of these top plates so it would be first come first serve for anyone interested.