Who can fix Supratek preamp???

I looking for some lead to fix my supratek cortese . It had a loud hum after one hour of playing. I sent to the local tech guy and he could not fix it. I need schematic or someone who know how to fix the preamp. Thanks for all advices and sugestions.
Kevin Covi co-designed the Cortese. He is located in the U.S. Try krcovi@gmail.com.
Hello,My Chardonnay is in the local shop for repairs.The tech needs a schematic,I just moved .I setup my system and no sound.I checked the connections.When I checked to make sure the umbilical was snug,it turned too far and made a sparking sound .I turned off the power.The local tech said the wires inside had come off.He said one end is color coded and the other is not.3 wires ? I bought it 2005 stock.I have emailed Mick,no answer yet.Does anyone have a schematic they can send to Josh at audioworkshop1@gmail.com .Thanks,I sure miss my music,I would be grateful for any help! My email is rayanthem@yahoo.com
Please email me. gary.mf1@gmail.com
Gary ,Thanks for responding!I will email you .
I have a syrah. I believe the schematics on the Suprateks have changed over the years, in some cases quite a bit so getting one's hands on a schematic may not be enough.

Winsound, in some cases the hum may be to some type of tube resonance - I've had this happen on mine, but is easily resolved by just tapping the tubes with my finter nail and I find such a hum immediately goes away - just though I'd mention, in case your issue is the same one.