RCA 5692 6SN7
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2222733508&category=7275#ebayphotohosting
[upload=jpg]uploadImages/200427215590054.jpg[/upload]
比较恐怖!!!!!!!!!
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3076410994&category=50598
再看这个:
http://www.tubeseller.com/catalog/i9.html
我现在的6SN7:稀罕物呀!
6SN7GTA / GTB:
This is the later improved version, and the improvements were primarily geared toward the TV chassis designers who demanded more max. plate wattage and voltage, where vertical circuits can put up to 1500 volt pulses at 7 watts on the plates. For hi-fi audio use, these improvements are meaningless. These are fine tubes, nonetheless. Most are found in the short glass envelope, but some brands like Raytheon used the Tall Boy style. Sylvania made tubes have the triangular plates mounted lower, and set at angles to each other, although some of the very earliest examples of the GTA types still used the dull blackplates facing each other. RCA used the flat black plates "sideways" to each other, and GE used the grey plates parallel to each other. The Sylvania types in demand have a large top getter patch. The earliest Sylvania GTA types have a green label and heavy top getter flashing extending down the sides of the tube. The early GTB types are similar, but have a yellow or red label. The versions from the 1960s have the getter just covering the top of the tube. All of these have the same black triangular plates and are excellent tubes. The GE types have a side getter and large parallel grey plates, and the RCA used both bottom or side getter. Most other vintage USA brands you find will have been made by these three vendors, and will be one of the above variations, regardless of brand on the label. A few were made with brown micanol bases, the RCA types being very dark brown, the GE types being a lighter, marbled brown. Many audiophiles prefer either the Sylvania chrome tops, the RCA, or the GE side getter over any others, even over the military or redbase types. These are all a great bargain now, and are sure to be rare and expensive tomorrow.