[3083joe]

I am not Glenn, but I am a bit of a collector.  I have never seen a Tung Sol 274b.  The only rebrand I have ever seen are Electronic Enterprises labeled 274Bs that were made by WE.  There are some later Electronic Enterprises (in 1956) that were made by WE, but the plates are slightly different than the normal WE 274B.  Then you have the Sylvania Navy 274B tubes, that largely predate the WE tubes.  The tube I am really interested in is the STC 274B version.  I have seen a few of the STC tubes, but never have heard one.

Pics

 

[Sfox7076]

I just saw one of those pop up on Ebay.  I have 40s and 50s 274Bs from Western Electric and Sylvania.  The mica plates on the top are a dead giveaway that that tube was made by Sylvania.  You can see pictures of the Sylvania one like I have in this Japanese auction:  http://yahoo.aleado.com/lot?auctionID=f155796427  That is the same as the Tung Sol pics you posted. The mica on the WE tubes look like this:  http://www.ebay.com/itm/Pair-of-vintage-Western-Electric-274B-with-square-getters-5752-5852-/252040439379?hash=item3aaec7e653.  Another issue I see with that tube is that I have never seen WE use an etched side on a 274B, and certainly not a stop sign.  The font mismatch on the base for Tung Sol and 274b unnerves me a bit as well.  So I cannot say definitively that the ones you sent are not WE made.  But, well, they look a lot more like the Sylvania 274B tubes than the WE made 274B tubes.  I would not be shocked if that is a rebase of a Sylvania with someone doctoring an old Tung Sol octal socket or, possibly, Tung Sol rebranded a few many years in the past.  Regardless, I would not buy it as a WE tube.    If you can get it for $150-$250, it would be worth it to compare it to a Sylvania up close as  it is also a good sounding tube.  Probably my 304th favorite rectifier.  But, well, there is a difference in sound between the WE and the Sylvania.  At least in my applications.
 
I will note that the Sylvania 274b tubes were made in the 1940s for the war effort.  Most I have seen are 1942-1943, predating most of the WE 274B tubes on the market.

 

[3083joe]

I just saw one of those pop up on Ebay.  I have 40s and 50s 274Bs from Western Electric and Sylvania.  The mica plates on the top are a dead giveaway that that tube was made by Sylvania.  You can see pictures of the Sylvania one like I have in this Japanese auction:  http://yahoo.aleado.com/lot?auctionID=f155796427  That is the same as the Tung Sol pics you posted. The mica on the WE tubes look like this:  http://www.ebay.com/itm/Pair-of-vintage-Western-Electric-274B-with-square-getters-5752-5852-/252040439379?hash=item3aaec7e653.  Another issue I see with that tube is that I have never seen WE use an etched side on a 274B, and certainly not a stop sign.  The font mismatch on the base for Tung Sol and 274b unnerves me a bit as well.  So I cannot say definitively that the ones you sent are not WE made.  But, well, they look a lot more like the Sylvania 274B tubes than the WE made 274B tubes.  I would not be shocked if that is a rebase of a Sylvania with someone doctoring an old Tung Sol octal socket or, possibly, Tung Sol rebranded a few many years in the past.  Regardless, I would not buy it as a WE tube.    If you can get it for $150-$250, it would be worth it to compare it to a Sylvania up close as  it is also a good sounding tube.  Probably my 304th favorite rectifier.  But, well, there is a difference in sound between the WE and the Sylvania.  At least in my applications.

I will note that the Sylvania 274b tubes were made in the 1940s for the war effort.  Most I have seen are 1942-1943, predating most of the WE 274B tubes on the market.

Thanks so much.

 

[Sfox7076]

I meant base, not socket, but you got what I meant.

 

[Sfox7076]

Also, be careful, there are a lot of old 274B fakes that are Sylvania's (or worse) with either rebases or fake bases.  One way to tell is often the font on the tube or the date code.  As far as I know, if WE made it with a WE label and it is post 1946 it will have a date code that is either three or four digits.  The last two digits will be 13, 26, 39 or 52.  That corresponds to the quarter of the year the tube was made.  From 1946 through the first quarter of 1956, only the last digit of the year was used, so first quarter of 1947 will be 713. Post 1956, it will be the two digit year, so 5713.  There is potentially some overlap in the first quarter of 1956, so that a 613 could be first quarter of either 1946 or 1956, but that is the only overlap.  I have seen some of the oddest date codes out there.  Mostly on hanging filament 5U4Gs that have been rebased or altered. People also don't take kindly to you when you tell them there tube is questionable, so you don't want it anymore...   For me, the fun comes with the engraved glass top tubes.  The dates are marked by weird etchings in the glass bottom.  
 
Back to the 274B, there are always ones that make me scratch my head.  This one looks right to me construction wise, but the label is off for the date code and the font of the tube type (not to mention it looks a bit wavy).  Maybe because it is a Jan tube it is different?  I don't know, but it would keep me away:  http://www.ebay.com/itm/Western-Electric-JAN-274B-with-square-getters-323-/331640021494?hash=item4d374921f6&nma=true&si=MtB%252FoxSSdPGIvp7bjWVhJcq4RRk%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557, 
 
OK, back to the Glenn amps. What is your favorite output tube and why?
 
Shawn

 

[3083joe]

Sfox7076
As for output tubes. Honesty I'm not sure.
I did read a review where a guy was using Glenn's amp with 6 output tubes.

 

[Sfox7076]

6 is crazy unless that is just rolling tubes. If there are 6 sockets to fill, I would spend too much in tubes, unless they were all 12SN7s or 13D1s.

 

[gibosi]

6 is crazy unless that is just rolling tubes. If there are 6 sockets to fill, I would spend too much in tubes, unless they were all 12SN7s or 13D1s.

 
http://www.tweak-fi.com/apps/blog/show/42754587-building-a-reference-system-part-2-glenn-s-headphone-amplifier

 

[3083joe]

http://www.tweak-fi.com/apps/blog/show/42754587-building-a-reference-system-part-2-glenn-s-headphone-amplifier

Funny I was just posting that.
Anyways here's what it had

Six 6BL7 tubes or
- Six 6SN7 tubes
- Two or four 6AS7 tubes
- Two 6336 tubes

 

[Sfox7076]

OTL. That explains it. Never owned an OTL amp.

 

[2359glenn]

OTL. That explains it. Never owned an OTL amp.

The six 6BL7s sound the best and they can be gotten for $6 or $8 each for new RCAs
cheaper then premium 6AS7s  

 

[Rossliew]

Glenn, have you built any OTL with EL86 tubes? Reckon they would sound good?

 

[Clayton SF]

I'm so happy Clayton is coming to my wedding all the way from San Francisco

Carry on.

 
Yes. I'm looking forward to being at your wedding. Sorry we couldn't get together last month when I was in Amsterdam. So, I return to Europe in November to drink beer with you again! Fun!
 
By the way, I am still looking for some dance shoes.
 

  So, this would be a good time for me to head to San Francisco and watch over all of Claytons audio gear   

 
I've built an underground bunker to protect my gear. Although, if you're in town, drop on by to give a listen or three.

 

[gibosi]

I present an FDD20, manufactured in the early 1940's by Philips Italy, which I strongly suspect is simply a 6N7 with a different heater (13V) and a different base (P8A). Shown here running at 12.6 volts in a Glenn OTL using a simple pin adapter from eBay.
 

 
And now back to our regular programming of food and weddings.

 

[Sfox7076]

Here is another example of a Sylvania faked into a WE.  I am done posting on this, but here you go:  http://page18.auctions.yahoo.co.jp/jp/auction/w124821733