I have serviced /upgraded several highly rated pre amps over the last few months. These include Ming Da, Accoustic Research, and Conrad Johnson models. The embarrassing bit was I felt these gave a slightly better performance than my modified Aikido. somehow they were that bit more musical, ‘funky’ where the Aikido erred on the side of strict neutrality.
Obviously something had to be done. One of the reasons I selected the Aikido design was because I don’t need much gain as my 300b power amp is very sensitive.
A vigorous Internet search came up with a design called the ‘Blue Velvet’ which met all my parameters, with some modifications. I knocked up a breadboard version and that sounded sublime, so I decided to proceed with a proper built version. for some reason I decided to make a ‘Fender Blue’ or ‘Powder Blue’ chassis, using guitar paint. Hopefully it’s easy to get a good finish. With 12 coats and ten days curing before polishing it better had be!
Below the photos show my original mock up, the current prototype running off my Homebuilt psu, and the chassis with 7 of its 12 coats!