One thought on “Tung-Sol 5687 Flat Ribbed Plates D-getter”

1. And finally, we come to one of the most famous and elusive valves in the audio world: the Tung-Sol 5687 with flat ribbed plates. This tube features a construction strikingly similar to the 12AU7 and is quite easy to identify even in low-quality photos. The majority of these specimens utilize a D-getter that extends straight up, resulting in a characteristic one-sided getter flash. I have also encountered versions with these same plates featuring a raised horseshoe getter, similar to later production 5687s with standard plates.

   Regarding the sonic performance: NICE. This tube is incredibly rich, offering superb bass and excellent high-frequency extension. Sonically, it bears a strong resemblance to the RCA 12AX7 with a D-getter, though the Tung-Sol provides a noticeably tighter low end. When compared to the standard version with vertical ribbed plates, this variant delivers a creamier and richer sound, even if the vocals lose a tiny bit of delicacy in the process. Overall, it is a fantastic tube with a lush, creamy vintage sound that truly deserves its legendary status. It is HIGHLY RECOMMENDED.

   Tung-Sol’s Role in Early Tube Production

   Tung-Sol Electric Inc., based in Newark, New Jersey, was a titan of early American vacuum tube manufacturing. While many competitors focused on high-volume consumer radio sets, Tung-Sol carved out a niche as an elite engineering firm. They were often the first to market with innovative designs; most notably, they were the original developers of the 6550 power tube and the 5687 dual triode.

   Their role was particularly vital during the transition to high-fidelity audio, as they set the electrical standards that other manufacturers—including RCA and GE—would eventually follow. In the early days of production, Tung-Sol was synonymous with ruggedness and precision, as their tubes were frequently selected for critical industrial and computer applications where failure was not an option. This commitment to structural integrity is why their vintage “flat plate” designs remain some of the most durable and sonically stable tubes available to collectors today.

   Final Verdict
   The Tung-Sol 5687 Flat Ribbed Plates is a vintage heavyweight. It trades the surgical precision of modern tubes for a rich, authoritative, and creamy tonality that breathes life into any system. If you can find this elusive D-getter variant, it represents the absolute pinnacle of the 5687 family.

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