The 5691 Red Base tube is a premium low noise version of the 6SL7-GT tube. Our current stock is the black-plate construction and most are labeled by RCA, but we do have some other brands as well. All were made by RCA regardless of branding. The RCA "Special Red" tubes (5690, 5691, 5692, 5693) were designed for 10,000 hours of use when used within their ratings. RCA claimed the 5691 tube could withstand shocks of 100 G's for extended periods of time! Availability: Out of stock.  Other NOS Treasures
 6SL7 Tube Types |
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