[JKDJedi]

Bottom mica looks like early sylvania

I have a pair that are just Hytron labeled (no CBS). Have the bottom D-getter, but 3 hole plates:




Then another pair, same Hytron-only label, same bottom D-getter, but 2 hole plates. Interestingly, all 4 have the same date code of 51-39:



These are CBS labeled, but no Hytron. Short bottle, angled T-plates:



Then you turn it over, notice the etched dots, and spend the rest of the afternoon cleaning the hurl off the keyboard:



And then the Hytron AND CBS labeled 5692. Flat plates. Can't see the getter shape at all as it's obscured by the flashing. One of my favorite tubes in Cary preamps, but didn't light my fire in the Lyr 3 or the Vali 2. Haven't tried it in the Incubus:

Bottom mica looks like early sylvania

I concur, just questioning the D getter . If Sylvania used D getters in 1945 then it's an early Sylvania in my book (the other detail I noticed is that a lot of the Sylvania photos out there show large lower getter flash material at the bottom, and a lot of photos of CBS-Hytron show hardly no getter flash material at the bottom.. )... And that 5692 sounds great on the Incubus.

 

[Ripper2860]

I have a pair ... <insert make/mfg>...

Why am I not shocked.

 

[highstream]

Given your curiosity in the Hytron's, I'll pass along my epxerience wtith eBay seller gizmo440, who has several posted. He doesn't test for noise or microphonics. I purchased a pair of 1953's from him last month for a Supratek preamp, and one was noisy right off. He sent a replacement right off, which worked great. But then after a few days I turn on my gear and then go fix lunch when I hear this loud machine like hum. Thought it was from the crew outside working on the condos across the way, but it was the other of the original pair apparently vibrating internally. Happened a few more times in the coming days after either turning on the preamp or just touching a balance knob by that tube. Tapping the tube stopped it, short of turning off the preamp, but this was more microphonics than normal. Otherwise, they sounded very good. However, this time gizmo440 claimed he didn't have any more Hytron's and so I returned the three and got a full refund. Looking today, he's got several for sale, including the ones he sold me.

I'd go with a 5692 pair, except they are going dear (Upscale Audio has them at $200 a pop).

I decided to go with a different pair just now, but the ones I was asking about are on eBay, titled " CBS 6SN7GT PERFECT MATCH PAIR 2 HOLE BAD BOY BLACK PLATE D GETR TEST NOS 1955," and look like... (there's a top view online)

 

[JKDJedi]

Given your curiosity in the Hytron's, I'll pass along my epxerience wtith eBay seller gizmo440, who has several posted. He doesn't test for noise or microphonics. I purchased a pair of of 1953's from him last month for a Supratek preamp, and one was noisy right off. He sent a replacement right off, which worked great. But then after a few days I turn on my gear and then go fix lunch when I hear this loud machine like hum. Thought it was from the crew outside working on the condos across the way, but it was the other of the original pair apparently vibrating internally. Happened a few more times in the coming days after either turning on the preamp or just touching a balance knob by that tube. Tapping the tube stopped it, short of turning off the preamp, but this was more microphonics than normal. Otherwise, they sounded very good. However, this time gizmo440 claimed he didn't have any more Hytron's and so I returned the three and got a full refund. Looking today, he's got several for sale, including the ones he sold me.

I decided to go with a different pair just now, but the one's I was asking about areon eBay, titled " CBS 6SN7GT PERFECT MATCH PAIR 2 HOLE BAD BOY BLACK PLATE D GETR TEST NOS 1955" and look like... (there's a top view online)

Good to know...thanks... I'll stay away from that seller for sure. I had purchased a Black JAN NU couple weeks ago and the seller accidentally sent me a Raytheon he was apologetic about it of course. Sent it back to him yesterday.

 

[JKDJedi]

Well you made me go look into the candy store and I couldn't resist grabbing one. .. thanks . I think.

 

[highstream]

Well you made me go look into the candy store and I couldn't resist grabbing one. .. thanks . I think.

I received my pair today and got a surprise worth mentioning. They are CBS/Hytron 6SN7GTB Pair Side "D" Getter - Angled "T" Plates, CBS 1959 and Hytron 1960, measuring NOS like. Gizmo’s ones from the early ‘50’s that I returned had been modestly warm and inviting, similar to but an improvement on the Shuguang WE6SN7 I'd been using. These new ones, however, a dozen hours in are very different: clean, transparent, precise and tonally accurate, but just enough less warm to not feel drawn in, and a touch farther back and thinner with noticeably less body/resonance, and hence sense of presence. So much different that one's singer's voice was actually unrecognizable (her inflection disappeared). Of course, another 250-300 hours of burnin ahead, but nothing like expected so far. Maybe the CBS/Hytron went through a change in the late ‘50s?

 

[highstream]

Among the myriad of Sylvania 6SN7GT's available, I'm trying to identify these. Round mica with two posts, clear top, two-hole, but photos aren't great. Seller says date code is 126, but not sure if that means 1951 or could that be 1961. Any thoughts? Thanks,

 

[Ranger Ron]

Among the myriad of Sylvania 6SN7GT's available, I'm trying to identify these. Round mica with two posts, clear top, two-hole, but photos aren't great. Seller says date code is 126, but not sure if that means 1951 or could that be 1961. Any thoughts? Thanks,

1951.

 

[JKDJedi]

Among the myriad of Sylvania 6SN7GT's available, I'm trying to identify these. Round mica with two posts, clear top, two-hole, but photos aren't great. Seller says date code is 126, but not sure if that means 1951 or could that be 1961. Any thoughts? Thanks,

Not sure on the dates but I do like how they sound. A touch livelier than the normal laid-back sound of the Sylvanias in that time frame (mentioned above)

 

[sennfan83261]

Not sure on the dates but I do like how they sound.

Not really a fan of the flat-plate Sylvania 6SN7GT's myself. The ones that came across my DV336 were a step below their t-plate brethren to my ears. It could be that the few that I took a flyer on may have been near the end of their lifespans.

 

[Ranger Ron]

I liked them at first, grew tired of them after a few days. Something about them fatigues me. Guy I bought them from said "one of the great hidden treasures of 6sn7" I dont think so. Maybe I'll try them again someday when all else fails.

 

[highstream]

I'm trying to identify these tubes in the model range, not how they sound -- unless of course you listened to the exact same model.

 

[Ranger Ron]

I'm trying to identify these tubes in the model range, not how they sound -- unless of course you listened to the exact same model.

Yes, the same model. 1951 flat plates, round micas.

 

[highstream]

Thanks for the info.

 

[Ranger Ron]

absolutely. They are impressive looking tubes I think.