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GB 6SN7WGT Sylvania Gold Brand in original boxes: maybe the only NIB pair on the WEB!
This is a pair of New In Box Sylvania Gold Brand 6SN7WGT tubes made in the USA. The tubes have the Gold Brand code etched on the glass; GB 6SN7WGT. The tubes have special alloy Rhenium-Tungsten heater wire, rugged construction and gold plated grid wire. Th life time is guaranteed for 10.000 hours which implies that in normal audio practice they will live probably much longer.
> Sylvania introduced Gold Brand in the middle of the 1950s to compete with the premium versions of other companies. Practically all companies that produced vacuum tubes had their own “Gold Brand”. For example, Mullard introduced 10M series. Philips had PQ (Premium Quality). Gold Brand tubes have been designed to work in critical industrial, military, and commercial applications. The tubes assured dependability under mechanical (500g) and thermal shock conditions (330 F and 165 C). The tubes were tested under crazy conditions to maintain electrical characteristics and reliability. As a result, tubes in Gold Brand were guaranteed to have an average life of 10,000 hours (5,000 for regular tubes).
Practically all tubes in the Gold Brand series have earned legendary status among audiophiles. This GB 6SN7WGT is no exception. This 6SN7 version is probably the best vintage 6SN7 ever made. I refer to the many threads on the web for more information.
Sonics
This valve excels in superior linearity, low noise, musical presentation, detail and smooth extended highs. No other 6SN7 equals its sonical performance! The gold grid wires and robust construction certainly contribute to this.
> Probably the best vintage 6SN7 types ever made.
Quotes on the WEB:
- it’s no wonder that all tubes in Gold Brand are hunted down to extinction.
- GB BUILT-IN RELIABILITY: Qualities of GB Gold Brand Tubes are 10,000· hour life, exceptional stability, maximum uniformity, and extreme phy· sical ruggedness.
For detailed information about the Sylvania Golf Brands series select this link: Gold Band info.
Note: my tubes are often not the cheapest. But is hard to find better tubes !
Electrical Test Data*
The test results below show that both are matched and balanced extremely well. And perfectly fulfil the specification of a new tube.
| Valve 1
V69 |
Ia (anode current):
Transconductance (Gm): Gas test, Shorts test: |
9,9/ 9,4 mA
2,8/ 2,7 mA/V OK |
= NOS
= NOS
|
| Valve 2
V70 |
Mu (amplification):
Transconductance (Gm): Gas test, Shorts test: |
9,4/ 9,3 mA
2,7/ 2,7 mA/V OK |
= NOS
|
The rated emission value for a new 6SN7 is: 9 mA. The rated transconductance value for a new 6SN7 is: 2,6 mA/V. As specified by factory data sheets and in AVO Valve Data Manual 23rd edition 1981.
Test conditions and measurement equipment
Mutual transconductance, plate current, gas and shorts test equipment: AVO Mk IV (AVO Valve Data Manual 23rd edition 1981), RFT stabilised mains, Utracer3+, Philips PE 4832, 2x Korad KA3005P programmable power supply, 2x Keithley 2700 and 2x Fluke 145.
Test conditions: Ua (plate voltage) = 250 Volts, Ug (grid voltage)= -8 Volts and Uf = 6,3 V. Precision of the test voltages 1%; measurement after 10 minutes stabilisation. (Factory conditions see data sheets (last 2 pictures)).
* For test methods and factory specification read the tube testing page.
Short description
| Tube type | GB 6SN7WGT |
| Quantity of Tubes | One pair |
| Brand | Sylvania Gold Brand |
| Manufactured in | Owensboro, USA |
| Dates | BA AAB (1954 til 1962) |
| Construction | Black plate, gold grid, rugged construction |
| Getter Construction | Halo getter |
| Print Condition | See pictures |
| Box included | Original Gold Brand Sylvania box |
| Equivalent tubes: | 6SN7, 5692, 6SN7GT, 6SN7GTB |
| General test results | NOS NIB |
For detailed information about the Sylvania Golf Brands series select this link: Gold Band info.
