[JackarlTwo]

OK - back to real tubes again. In these days of ever escalating prices of desirable tubes I have found a garden variety RCA 6SN7GT that IMHO is a top tier tube. This tube should be inexpensive but it is a little hard to find but not because it is rare; I'll explain:
This 6SN7GT tube is from the late sixties. RCA made several different such tubes, but I only found one variant that sounds great. This variant has a little heater wire above the top mica and black parallel plates. All the ones I have seen have red print on the base. There are also rebranded such tubes that should make them even cheaper (I have pair Stromberg-Carlson branded ones - S-C was a radio manufacturer). The problem is that most such tubes when pictured in the ads don't show that little heater wire. Here is a spotters guide:

My tube in action; more pictures below:




If anyone has this variant, please try it and let me know what you think of the sound.

I've been using these tubes for a while now. Sounds pretty close the RCA VT-231 gray glass I have, but not as rolled off up top I think. Very good sound imo, especially for the relatively good price.

 

[mordy]

I've been using these tubes for a while now. Sounds pretty close the RCA VT-231 gray glass I have, but not as rolled off up top I think. Very good sound imo, especially for the relatively good price.

Glad you like them. IMHO this tube is a sleeper and deserves a little recognition.

 

[Jon L]

Glad you like them. IMHO this tube is a sleeper and deserves a little recognition.

These RCA tubes seem to be late 1960's 6SN7GTB's not 6SN7GT per se..

 

[mordy]

These RCA tubes seem to be late 1960's 6SN7GTB's not 6SN7GT per se..

Yes, you are right - GTB.

 

[Jon L]

Yes, you are right - GTB.

I ordered a pair to complete my 6SN7 collection, but I have sold off all my tube gear using 6SN7's. What a crazy addiction..

 

[TLO]

I ordered a pair to complete my 6SN7 collection, but I have sold off all my tube gear using 6SN7's. What a crazy addiction..

It's OK, you may send your collection of 6SN7 to me. I will help you to give them some love in my rotation...

 

[bcowen]

This is the bent "central" pin I'm worried about, but I've tried the tube for hours and no issues. The base itself and tube is super rigid.

The 'center pin' I think you're referring to is the bottom of the glass bulb. It's not bent, that's just the way it formed when it was manufactured. Don't try to straighten it, you'll just break the glass and the tube will be dead forever.

Highly recommend the octal key replacements mentioned earlier. Orient correctly, add a couple drops of super glue, and you're as good as new without having to worry about inserting the tube incorrectly in the future. Having a couple spares won't hurt either, as you'll likely break another center pin at some point. Not that I speak from experience or anything...

 

[JackarlTwo]

The 'center pin' I think you're referring to is the bottom of the glass bulb. It's not bent, that's just the way it formed when it was manufactured. Don't try to straighten it, you'll just break the glass and the tube will be dead forever.

Highly recommend the octal key replacements mentioned earlier. Orient correctly, add a couple drops of super glue, and you're as good as new without having to worry about inserting the tube incorrectly in the future. Having a couple spares won't hurt either, as you'll likely break another center pin at some point. Not that I speak from experience or anything...

Yeah I quickly noticed it's just a part of the glass, I wasn't sure if it was supposed to be bent like that. For now I just use a marker to easier identify the correct orientation.