Hi Everybody,

First time poster, long time lurker. I have a lot of experience working on and designing tube amps, but have only dabbled a bit in solid state amps. I've been commissioned to design an amp for a friend ("commissioned" is a fancy way of saying build for free/fun) based on a beloved weirdo Japanese solid state amp he has. The amp is a Princeton "Prince" T-70 model. From the very little I've found about them, they seem to have been built by Panasonic. I'm not expecting anyone to be familiar with this particular amp, but I was hoping that maybe somebody was familiar with any other amp designs that used the C1815 transistor. I'm curious to see if there's a more common model (one with readily available schematic for example) that also used this NPN transistor as the basis of its pre-amp.

Any help or pointing in a direction would be infinitely appreciated! Thanks!