I do a few tube preamps.
This is my main Jupiter preamp which is a take on the SLO lead channel with a built in overdrive and 5 band GEQ. It also spits out the dry DI so you can run that to an interface for recording or to another amp/preamp.
I have a few others such as mkiic+, wizard MTL, VH4, Powerball and the newest that im prototyping which is a mostly original design thats a culmination of everything i've learnt over the years.
Typically though I just do DIY PCB sets for the above but I can do full builds too if needed.