Try this website.
www.rsvlonline.net/vintageamp/
From what i've heard, the "new" Threshold is working only on selected "older" models. The website listed above is that of one of the former "original" Threshold employee's that worked in the service department. Be forwarned though, he is slow to respond to email and this is strictly a "side job" for him. Nonetheless, his work is first rate. Sean
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