[UntilThen]

Actually it is better with them on the side. The side of the tube gets hotter allowing them to work when they are hot getting more gas out of the tube.
They still work when they get hot.

Now the world will descend on the side getters.

There are some RCA side getters on ebay. With round, square, D or horseshoe getters.

 

[gibosi]

Here are two RCA 6BL7 tubes from my stash:



The shortie is the side getter tube - considerably smaller

Yes, and the taller one with top getter and three mica is very likely a Sylvania.

 

[whirlwind]

Now the world will descend on the side getters.

There are some RCA side getters on ebay. With round, square, D or horseshoe getters.

I have some and I like them. They are short tubes with the narrow black base, they have the side getters, mine are round getters.
Sound nice. The ones I have are 6BX7, I don't have any RCA 6BL7

There is a thread that shows some nice pics of some different constructions of the tubes, and how to tell the brands.....gibosi knows all of them real well
Everybody made these tubes for each other....RCA, GE, Sylvania, I believe Tung Sol

 

[mordy]

Yes, and the taller one with top getter and three mica is very likely a Sylvania.

Hi Gibosi,

I see that I have to be very careful what I say - should have said "Here are two RCA labeled tubes" lol.
I am sure you are right - been awhile since I played these tubes. Got some two dozen different ones; many from the old 99c stores on eBay.
For some reason these tubes seem to be more cross-branded than others. The prize goes to a Tung Sol labeled tube with the telltale GE sand blasted dots.

 

[mordy]

Hi Gibosi,

I see that I have to be very careful what I say - should have said "Here are two RCA labeled tubes" lol.
I am sure you are right - been awhile since I played these tubes. Got some two dozen different ones; many from the old 99c stores on eBay.
For some reason these tubes seem to be more cross-branded than others. The prize goes to a Tung Sol labeled tube with the telltale GE sand blasted dots.

Here is a stash of 5998 tubes - ending in 30 min:
https://www.ebay.com/itm/302507419190?ul_noapp=true

 

[attmci]

Here is a stash of 5998 tubes - ending in 30 min:
https://www.ebay.com/itm/302507419190?ul_noapp=true

Don't buy these weak 5998s.


The min. Gm value is 10000 and spec is 15000. The results are as follows:

Tube #1 10500/10500

Tube #2 11500/11500

Tube #3 10500/10500

Tube #4 10000/10750

Tube #5 11500/10500

__________________

Here is the old 6bl7 thread.
https://www.head-fi.org/threads/for-6bl7-tube-users.806043/

Also a lot of info. @ the 6as7g thread.

 

[gibosi]

Hi Gibosi,

I see that I have to be very careful what I say - should have said "Here are two RCA labeled tubes" lol.
I am sure you are right - been awhile since I played these tubes. Got some two dozen different ones; many from the old 99c stores on eBay.
For some reason these tubes seem to be more cross-branded than others. The prize goes to a Tung Sol labeled tube with the telltale GE sand blasted dots.

It appears that among American manufacturers, RCA and Tung-Sol did not begin to manufacture 6BL7 / 6BX7 until around 1960. Before that time, both RCA and Tung-Sol sourced their tubes from GE and Sylvania.

 

[mordy]

Don't buy these weak 5998s.


The min. Gm value is 10000 and spec is 15000. The results are as follows:

Tube #1 10500/10500

Tube #2 11500/11500

Tube #3 10500/10500

Tube #4 10000/10750

Tube #5 11500/10500

__________________

Here is the old 6bl7 thread.
https://www.head-fi.org/threads/for-6bl7-tube-users.806043/

Also a lot of info. @ the 6as7g thread.

Hi attmci,

Thanks for pointing this out - did not look that closely at the auction. -Out of curiosity (and since many of my tubes were bought used or not tested), what would be the practical result of using a tube that just passes the minimum for being acceptable? Would it last less? Less volume?

I seem to remember that some people did not put too much emphasis on measured values. Personally, I can't remember wearing out a tube - lost 3-4 tubes over the years due to breakage from dropping them, and another 2-3 lost their vacuum being stored and died the white death....

Come to think of it, it could be that a couple of dual triodes with very mismatched values between one triode and the other would throw off the centering of the soundstage. ( I would move my listening chair right or left or use the balance control lol)

However, at this stage I am mainly using NOS tubes. BTW, the Fotons don't break from being dropped accidentally.....

 

[attmci]

Hi attmci,

Thanks for pointing this out - did not look that closely at the auction. -Out of curiosity (and since many of my tubes were bought used or not tested), what would be the practical result of using a tube that just passes the minimum for being acceptable? Would it last less? Less volume?

I seem to remember that some people did not put too much emphasis on measured values. Personally, I can't remember wearing out a tube - lost 3-4 tubes over the years due to breakage from dropping them, and another 2-3 lost their vacuum being stored and died the white death....

Come to think of it, it could be that a couple of dual triodes with very mismatched values between one triode and the other would throw off the centering of the soundstage. ( I would move my listening chair right or left or use the balance control lol)

However, at this stage I am mainly using NOS tubes. BTW, the Fotons don't break from being dropped accidentally.....

You will notice when a tube is dying. I trust a tube tester, and try to get rid of tubes which test below acceptable level. You can also find leaking, short tubes etc. before install them in your valuable amp.

Oh, Glenn had a 300B gone bad sometimes ago. Generally, driver tubes last much longer than power tubes.

I cannot believe those 5998 tubes were sold for almost $300. On the other hand, the seller is very honest about the status of these tubes.

 

[attmci]

What you talking about guys. I will show you clear tops !!!

The Fivre 6BX7 just arrived. Only 3 sadly. As you can see the top is clear because the getter is at the side. That's where the chrome is. Pretty unusual. The Italians do things differently.

I had read this a couple of times: https://www.radiomuseum.org/forum/an_overview_of_italian_vacuum_tube_manufacturers.html

I still don't understand what the "M8" code on a SICTE rectifier tube indicates. Oskari? I see you are here.

 

[jelt2359]

mros, thanks for the feedback. Responses such as this will benefit everyone.

Most of my power tubes were bought when I had Elise and Euforia. I have gotten to know their sound signatures well over a 2 year period. gec 6as7g, bendix 6080wb, gec 6080, mullard 6080, 5998, 7236, rca 6as7g, svetlana 6H13c, rca 6080, ge 6as7ga, chatham 6520, chatham 6as7g. They all have their unique, distinctive tone. Do I have favourites? You bet.

Without comparing, I too could love and enjoy a pair of economical RCA 6080. However, like red wine, once you compare, you will discern that they differ more than just the different shades of the colour red. You will also start to form opinions and pick your favourites. Not everyone is alike. So opinions will differ. Tubes will also sound their best for different genre of music and the tempo. I find it hard to categorically state that a gec 6as7g is better than a 5998. It really depends on what I listen to and the partnering source and headphones. One is silky smooth and enjoyable while the other is excitable, energetic and dynamic.

Amongst the power tubes, I have my clear favourites. They are gec 6as7g, bendix 6080wb, gec 6080 and 5998. Unfortunately these are also the most expensive.

Tubes will also sound different from one tube amp to another. I have heard the gec 6as7g on Euforia and La Figaro 339. When you've listen long enough, you will discern the subtle difference. Sometimes the difference is more than subtle.

It is for the above statement reason, that I am eager to hear those tubes in my forth coming Glenn OTL. I've tried 2 x c3g and 4 x 6BL7 in Elise and Euforia but those amps weren't designed with those tubes in mind. I've no doubt that a custom made and tuned Glenn OTL amp, will sound different and superior with 2 x c3g and 6 x 6BL7. Well I will find out for myself.

On the same token, I pioneered the use of 6 x EL3Ns in Elise. 2 as drivers and 4 as power tubes. These tubes in Elise that is not designed for it, sounded warm and lush, have an expansive soundstage and a very rewarding bass. I have no doubt that a very well designed Glenn EL3N amp with the option switch of pentode and triode, will sound very much different. Hence I'm very eager to hear a Glenn EL3N too.

Confused, so are you getting the GEL3N or the GOTL?

 

[whirlwind]

Jason, your collection of gear is phenomenal.

 

[UntilThen]

Confused, so are you getting the GEL3N or the GOTL?

I'm getting a GOTL. Glenn is starting the build this week.

GEL3N next year.

 

[UntilThen]

I lost out on an auction for 12 brand new RCA 6bx7 yesterday. With 4 secs to go I was the leading bid at US$126. I had a max high bid of US$150. When it ended, it sold for US$197.

I'll be satisfied with the tubes I have presently:-

10 x 6BL7gt and gta
9 x 6bx7

 

[Oskari]

I had read this a couple of times: https://www.radiomuseum.org/forum/an_overview_of_italian_vacuum_tube_manufacturers.html

I still don't understand what the "M8" code on a SICTE rectifier tube indicates. Oskari? I see you are here.

The link was interesting but doesn't seem to offer any help with the code. Unfortunately I don't have much to offer either.