I have all of those AES papers about UD-4, as well as those on CD-4 and the matrix formats. I have already sent Jon much of it, which is what his new page on UD-4 will be based on. I hadn't sent the AES technical information, but will do so now. He (Jon) already has the information booklet that Nippon-Columbia offered to the press when the system was introduced for sale. I will scan and send the AES technical papers shortly. UD-4 was initially sold in the Japanese market, then introduced in England. Plans were for USA introduction when the quad market collapsed. I have supplied Jon with a complete disc release list. There was only one demodulator model sold, the UDA-100, which also demodulates CD-4 and has basic non-logic positions for SQ & QS as well. There were several prototype models made that only demodulate UD-4, having no CD-4 or matrix settings. I have the full schematics and service manual for the UDA-100. I once submitted the schematics to a contact at JVC in Japan who ran the CD-4 department back in the day. The UDA-100 is based on later JVC designs in the demodulation section, having automatic carrier level control. I have all the prototype models, some which play in the matrix only mode, and others that add the carrier directionality, in addition to the commercially sold UDA-100. I find UD-4 to be a fine system. The only albums that I can directly compare musically and separation wise to other formats are Quadraphile, Tubular Bells 4YX-9026, and the Buddy Cole 4RX-9012 which was released by Alshire in the USA on QS and Q8. I have never found the other title that would directly compare, 4RX-9011 The World of Bacharach & Webb / 101 Strings Orchestra. I'm pressed for time now, I'll post or send more information next week.
