Schematic of Counterpoint SA-5000 preamplifier

Dear friends, I'm writing from Spain. I have a preamplifier SA-5000 that its company Counterpoint produced in the decade of 90. When I acquired it the sound of my equipment hifi improved radically. Since then I've been in love with this preamplifier. After a while the appliance broke down and I had it stored and packed for several years, until one day I decided to repair it. For that I sent it to a technical service outside my province, in Valencia, which in theory was very good. The repair done by this technical service significantly altered the original configuration of the SA-5000, and eliminating 3 valves. After the repair the sound of the preamplifier is no longer the same. I know a Audio technical service that would rebuild it, but I can not find the electronic schematics. Does anyone know where I can find such schematics

Thanks and regards