The 6SN7 Identification Guide

[tintinsnowydog]

Does anyone know who made tubes for RTRA?

https://www.ebay.co.uk/itm/RTRA-6SN...700047?hash=item340924b54f:g:SekAAOSwMYRaftSa

I took a guess on another thread that these have similar plate and top mica supports as 6N8S, but am not sure.

Hello there, my most recent purchase is a pair of these. I guess they are what might be called type 1’s as there are just 2 support rods? Do the numbers give the date of manufacture? Or can it only be tied down to 40’s? Or 50’s

VT-231 suggests pre-1950. FE5 suggests 1945, but not too sure on the FE. A quick google found this ebay post
https://www.ebay.com.au/itm/RAYTHEON-VT-231-6SN7GT1945-JAN-CRP-ONE-TUBE-NOS-/264272379103
Original box agrees that LE 5 and FE 5 are 1945. F= June L= November/December potentially?

Edit: box stamped April 1945.

 

[GreenNeedle]

One more (I'm in an ebay mood today.)

From what I read Zalytron rebranded rather than manufactured tubes. This one clearly states on the base 1959 but it look similar to a Bad Boy to me. Did someone else manufacture a tube similar after Sylvania? Did Zalytron rebrand some much older tubes in 1959? Any details would be cool.

https://www.ebay.co.uk/itm/6SN7GT-Z...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

 

[attmci]

Seem to be same family:
http://www.nosvacuumtubes.net/product/mullard-philips-ecc33/
https://www.radiomuseum.org/tubes/tube_ecc32.html
good info and links: https://www.head-fi.org/threads/ecc31-ecc32-ecc33-ecc34-ecc35-tube-addicts.808322/ (note leftside's post 12)

But different tubes.

 

[Ranger Ron]

One more (I'm in an ebay mood today.)

From what I read Zalytron rebranded rather than manufactured tubes. This one clearly states on the base 1959 but it look similar to a Bad Boy to me. Did someone else manufacture a tube similar after Sylvania? Did Zalytron rebrand some much older tubes in 1959? Any details would be cool.

https://www.ebay.co.uk/itm/6SN7GT-Zalytron-Foil-Getter-at-Base-A-Used-Old-Stock-Valve-Tube-1pc-DEC19/193241313051?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649

Zalytron absolutely sounds like a rebrand.

 

[attmci]

Zalytron absolutely sounds like a rebrand.

It's a Syl. But cannot confirm it's a bad boy.

 

[Ripper2860]

Technically not a bad boy if the 1959 year stamp is accurate. Legit Bad Boys were late '51 to early '53.

 

[tintinsnowydog]

The internals certainly match up the criteria (3 hole, top mica spiked and pointing down, foil getter). Technically not a bad boy because it isn’t branded Sylvania and printed 1951/2/3, but it potentially sounds the same. Theres the same case of Canadian Marconi GTB with same internals, but different branding. Bases can be put on or printed any time, but the internals are most likely from the same run.

 

[cddc]

LOL, you guys are nit-picky on the year 1959.

Zalytron is a UK rebrander, it might order the batch of tubes from Sylvania in 1953, it took a year or 2 for the tubes to reach the UK, then sitting in their warehouse for another couple of years until Zalytron finally silk printed its logo and year 1959 on the base, and shipped them out.

That tube is a real bad boy.

 

[Ripper2860]

@cddc got in just before I hit submit.

All the characteristics of a Bad boy. IMHO - never fully trust any dates stamped on the base. Many times tubes are made well in advance of being mounted to a base. Rely on internal structure and on any codes etched onto on the glass envelope itself.

 

[attmci]

It's a Syl. But cannot confirm it's a bad boy.

Because I cannot see the internal structures. The seller intentionally hide the details.

You guys can see through?

 

[Ripper2860]

Enough of the internal structure is visible on the Zalytron to allow a relatively accurate assessment, IMHO. While we cannot see if there's a rectangular foil getter holder, the pics show: Copper posts. Bottom flashing extending up approx. 1/3 of tube. Top rectangular mica with 3- slightly downward pointing points on each of the short sides. Bottom rectangular mica. Ribbed t-plates with 3 rivet holes each. Those are all characteristics of the Sylvania-made 6SN7GT dubbed 'Bad Boy' by some folks. If the 1959 year on the base actually reflects the tube MFG date, then it most certainly falls well outside the range specified for a true 'Bad Boy', but as I stated previously -- the base is not the best indicator. Example: I have a 1945 Sylvania tall bottle / black base 6SN7W tube mounted in a 6SN7GT base. The tube is etched 6SN7W on the top of the envelope. All others I own and I've seen are in a base marked JAN CHS 6SN7W.

 

[attmci]

Because I cannot see the internal structures. The seller intentionally hide the details.

You guys can see through?

I saw three holes on one side only. Just different angles. I could be wrong. Don't care about the date at all.

BTW, the bad boy is not as good as a 6sn7w. Not worth the 40 plus pounds plus shipping price tag.

Your guy's
best friend has one bad boy on sale now (30% off):

https://www.ebay.com/itm/6SN7GT-BAD...612759?hash=item2af5de4bd7:g:60QAAOSwnF1fnKTg

 

[Ripper2860]

No thanks. I have several and never paid over $55 on average. And I agree, the W is a better sounding tube in my opinion.

 

[cddc]

I saw three holes on one side only. Just different angles. I could be wrong. Don't care about the date at all.

BTW, the bad boy is not as good as a 6sn7w. Not worth the 40 plus pounds plus shipping price tag.

Your guy's
best friend has one bad boy on sale now (30% off):

https://www.ebay.com/itm/6SN7GT-BAD...612759?hash=item2af5de4bd7:g:60QAAOSwnF1fnKTg

LOL....Menifee_Audio (aka BangyBang) is a notorious scammer. Not only he asks for 4x - 10x ongoing market prices, but also he is very sneaky on his tube measurements. He never tells you what tester he uses and when his tester was last calibrated, so it's basically the same thing as having no tester. And he is demanding extremely high prices...what a joke!

greengirl613 is slightly better than Menifee, though GreenGirl613 is also asking ridiculous prices and being dishonest (he uses lots of accounts to fool buyers, greengirl613, thegeminigirl, fng2u, oceanview_hi, ...., just name a few), his tube testing values at least seem normal.

Other suspicious sellers you guys should pay attention to are igolioto and brhines2012 . They use some crappy out-of-tune TV-3 and Mercury testers that often give 3500-3600 Micromhos to 6SN7 tubes. It is impossible for a 6SN7 (100% NOS = 2600 Micromhos) to reach such a high measurement, if you often check tube measurements on higher grade testers like TV-7 on fleabay, you'll know their numbers are just jokes. If you buy 6SN7's from them, make sure they test at least 3500 Micromhos on their testers, a 3100-3200 Micromhos tube from their testers could possibly measure only 80% on a truly calibrated tester.

Will let you guys know other suspicious sellers if I notice them.

 

[bcowen]

LOL....Menifee_Audio (aka BangyBang) is a notorious scammer. Not only he asks for 4x - 10x ongoing market prices, but also he is very sneaky on his tube measurements. He never tells you what tester he uses and when his tester was last calibrated, so it's basically the same thing as having no tester. And he is demanding extremely high prices...what a joke!

greengirl613 is slightly better than Menifee, though GreenGirl613 is also asking ridiculous prices and being dishonest (he uses lots of accounts to fool buyers, greengirl613, thegeminigirl, fng2u, oceanview_hi, ...., just name a few), his tube testing values at least seem normal.

Other suspicious sellers you guys should pay attention to are igolioto and brhines2012 . They use some crappy out-of-tune TV-3 and Mercury testers that often give 3500-3600 Micromhos to 6SN7 tubes. It is impossible for a 6SN7 (100% NOS = 2600 Micromhos) to reach such a high measurement, if you often check tube measurements on higher grade testers like TV-7, you'll know their numbers are just jokes. If you buy 6SN7's from them, make you they test at least 3500 Micromhos on their testers, a 3100-3200 Micromhos tube from their testers could possibly measure only 80% on a truly calibrated tester.

Will let you guys know other suspicious sellers if I notice them.

I've seen a number of igolioto's listings and never paid any attention to them because the prices were always ludicrous. But after looking at the stupidly priced one below, you're absolutely right on his test readings. 3125/3125? Yeah. Sure.

I have a TV-3 sitting in the closet. Despite my best efforts (and a lot of time spent on it) I cannot get it to calibrate. All of the Hickok military testers have a lengthy and arduous calibration procedure that requires some good test equipment, and there are very few people that can calibrate one correctly even if they have the equipment (Dan Nelson is one, but one of very few). Igolioto's TV-3 is nowhere near correct calibration (regardless of his claim) if he's getting test readings like that.

https://www.ebay.com/itm/2-NEW-Tung...614618?hash=item3433475e5a:g:rsUAAOSwSPFfi4DA