I've decided to sell off my Hafler gear and go 100% into tubes. Just got a Willsenton R8 running and love the sound. I've watched Stephie's review of the Muzishare X7 and that's a possibility. But I've always been intrigued by the ST-120. Anybody built one or heard one?

I purchased a used R8 without driver tubes. Tonight I installed a new quad of KT88's. Volume turned all the way down and powered it up. After about 5 seconds I got a very loud squeal from the right channel. I turned the power off and the squeal faded away. I disconnected all the inputs and tried again. Same story left channel is silent and right channel produces a scary loud squeal. Speakers are Klipschorn's. Any ideas? Swap V1 V2 and V3 V4? I have an old set of EL34'S I could try. I don't suspect input tubes since volume is all the way down. 30 day warranty just send it back maybe...