The Telefunken EF804-S tube is a special quality low noise tube that is rated to last over 10,000 hours. Telefunken made this tube for the professional audio/recording industry where it was used in microphones and mic preamps such as the V72.
Some are labeled Siemens or other brands, but all are actually Telefunken
made tubes and have the diamond logo molded into the glass at the bottom
of the tube.
Additional Information and Downloads
What does "NOS" mean, anyway?:
Commonly known as "NOS," the term New Old Stock simply refers to tubes that were made years ago but have never been used. Much like antiques, "NOS" tubes are currently not being manufactured and this means their supply is dwindling while the price continues to rise.
For most NOS tubes we have a variety of brands available. Typically these are the common brands such as RCA, Sylvania, GE, Raytheon, etc. However, there are instances where lesser known brands are in stock. If you have a particular brand you prefer you can simply request it in the Order Comment box when you place your order.
Warranty Information and Return Policy
Warranty Period: 3 months
All our tubes are guaranteed for 3 months from the date of purchase. (Any exceptions will be noted on that tube's Warranty tab)
If you receive a tube that does not perform to the manufacturer's specifications, please do the following:
- contact us to get a return authorization - return it via regular mail within 90 days from when we shipped it, and we will provide an exchange or refund of the full purchase price of the tube.
Returns not related to warranty or defect will be considered at our discretion, and are subject to a 15% restocking fee.
We can not accept returns that don't have an authorization, are past 3 month, or are returned improperly.