Sylvania 7687 NOS Audio Tubes Matched Pair - McIntosh Scott Dynaco

Sylvania 7687 NOS Audio Tubes Matched Pair - McIntosh Scott Dynaco

NOS/NIB Sylvania 7687 audio tubes. Low noise, low microphonics triode - pentode designed primarily for high-fidelity audio. Branded as Tronal for old TV sets. The tubes are true New Old Stock and New in Box. They share the same pinout and are pin-compatible with the US types 6U8, 6GH8, 6BL8, and the EU types ECF80, E80CF, as found in many vintage amplifiers by McIntosh, Scott, Fisher, etc. as well as some modern ones like many Dynaco clones and the ANK Audio Note L1. Also, an electrically direct replacement for the RCA 7199 as used in vintage Dynaco, for which this tube was designed, although requiring a socket adapter (you can get these cheap from eBay). 

From the original datasheet:
The Sylvania type 7687 is a triode-pentode designed primarily for High Fidelity audio applications. The pentode section is particularly suited for preamplifier service while the triode section is intended for use as a phase splitter. 

Type 7687 features exceptionally low hum and noise output. Although basing differ, type 7687 is similar to type 7199. Type 7687 is an improved low noise version of type 7199.