The Reference 6SN7 Thread

[g0ldl10n]

Quite likely. It's the loss of the electrolyte fluid (drying up, evaporating, leaking, etc) that normally causes their demise, and that process occurs regardless of usage.

Great! That is what I was wondering despite use

 

[Mr Trev]

Quite likely. It's the loss of the electrolyte fluid (drying up, evaporating, leaking, etc) that normally causes their demise, and that process occurs regardless of usage.

I was going to post a smart-ass reply, but I can't think of one. Maybe this is what's happening to my brain too?

 

[bcowen]

I was going to post a smart-ass reply, but I can't think of one. Maybe this is what's happening to my brain too?

Yeah, right. I know you better than that. You're just being polite. But that's scary too...

 

[LobalWarming]

I thoroughly recommend getting a modern tester. Especially if you have quite a few tubes. I just wish I'd have purchased both of mine earlier. Both have paid for themselves now.

Wow! That's great. Where did you find the Pay-To-Test Testers? Were they naïve young testers looking to get a pin up on unpaid intern testers?

 

[DropTekRoon]

Recently purchased a vintage RCA 6sn7gtb tube. I think it's from 1964. Idk what the general thoughts are on this tube, but it has a nice lush and smooth sound with a touch of warmth. Is this tube the same one that is being sold on tube depot for $100 each? It looks identical to it.

 

[TLO]

Recently purchased a vintage RCA 6sn7gtb tube. I think it's from 1964. Idk what the general thoughts are on this tube, but it has a nice lush and smooth sound with a touch of warmth. Is this tube the same one that is being sold on tube depot for $100 each? It looks identical to it.

In general, latter versions (GTA / GTB) is more to the "modern" sound...that's fast, high clarity but drier compared to earlier version. It is just a matter of personal preference, some like it hot and dry but most, including myself, like it hot and wet...

 

[DropTekRoon]

Interesting. I've also read that gta/gtb usually sound less tubey compared to gt, but not always. So pretty much what you just said. I guess I'll be on the lookout for a single 6sn7gt then. Hopefully I can find something good.

EDIT: Well, that was quick. Just bought a 50's Brimar CV1988 6sn7gty black plates and black base tube. Didn't expect that. Looking forward to trying it! Thanks @JTbbb

 

[sennfan83261]

Picked up these matched 6SN7GTA T-plates (mid-1953) for my Liquid Glass for a decent price. They are warm, withdrawn (larger soundstage?), and a bit murky sounding tubes with the LG (driving a HEKv1), which is strange because I loved these early GTA's in my Darkvoice (I know, different amps, different topologies, hybrid vs. OTL, blah blah). Too bad the magic didn't mostly* transfer over . I much prefer the more forward stock EH 6SN7's in the LG and any 6922, 6DJ8, 7308, 12AU7, and 5814's that I collected while tube rolling with the Liquid Platinum a few years ago.

Damn, I'm back in the tube rolling game.

Yeah, I'm not going to spend over the cost of the amp to grab a pair of NOS Mullard ECC32's.

*EDIT: Okay, they're getting better to my ears....

 

[triod750]

*EDIT: Okay, they're getting better to my ears....

And this will continue...

 

[LobalWarming]

And this will continue...

Yes it will. With the Sylvi 6SN7s, the Brimar 6SN7s, the Melz 1578s, with the ECC32s, ECC33s, ECC34s and the 6J5Gs and the 6J5GTs until the end of tube hoarding collecting

 

[DropTekRoon]

Can definitely be frustrating. I have two 6sn7 tubes that I planned to use for my Helot 2x. A Tung Sol 6sn7gtb and a vintage RCA 6sn7gtb black plates. Both have a hum/noise floor. The RCA one will have a hum/buzz no matter how low I have the volume. I can't hear it when audio is playing, but when nothing is playing and when there is a quiet part in a track, you will be able to hear it. The Tung Sol is a little better, but it has a weird crinkling/scratch noise from time to time and it will also hum/buzz. I get no noise floor with the 12au7 tube in the amp.

I previously tried using the same Tung Sol tube with the same pair of headphones in the Vali 2++ and I have the exact same noise that I get with the Helot. Which makes me think it's the tubes rather than the amp itself. Also, I can hear a faint ringing/buzz like sound occasionally if I put my ear close to the tube. Sigh.. It be like that sometimes

 

[triod750]

https://www.ebay.co.uk/itm/38547154...2FVV3sdGvEz8Jg%3D%3D|ampid:PL_CLK|clp:2047675

Do you have some spare cash?

 

[Ranger Ron]

Can definitely be frustrating. I have two 6sn7 tubes that I planned to use for my Helot 2x. A Tung Sol 6sn7gtb and a vintage RCA 6sn7gtb black plates. Both have a hum/noise floor. The RCA one will have a hum/buzz no matter how low I have the volume. I can't hear it when audio is playing, but when nothing is playing and when there is a quiet part in a track, you will be able to hear it. The Tung Sol is a little better, but it has a weird crinkling/scratch noise from time to time and it will also hum/buzz. I get no noise floor with the 12au7 tube in the amp.

I previously tried using the same Tung Sol tube with the same pair of headphones in the Vali 2++ and I have the exact same noise that I get with the Helot. Which makes me think it's the tubes rather than the amp itself. Also, I can hear a faint ringing/buzz like sound occasionally if I put my ear close to the tube. Sigh.. It be like that sometimes

I hear ya. You have to buy a lot of tubes to find that magically quiet one or two or three or four or five hundred tubes later.

 

[DropTekRoon]

I hear ya. You have to buy a lot of tubes to find that magically quiet one or two or three or four or five hundred tubes later.

Pretty much. I wonder if another possibility for the hum/noise could be overloading the amp transformer. The 6sn7 tubes do have twice the current than the 12au7. But I mentioned that I got the same noise from the same tube that was in the Vali that I'm getting with the Helot. So it makes me think the transformer isn't the problem. I guess the only way to find out is to keep trying more 6sn7 tubes like you were saying.

 

[LobalWarming]

Pretty much. I wonder if another possibility for the hum/noise could be overloading the amp transformer? The 6sn7 tubes do have twice the current than the 12au7. But I mentioned that I got the same noise from the same tube that was in the Vali that I'm getting with the Helot. So it makes me think the transformer isn't the problem. I guess the only way to find out is to keep trying more 6sn7 tubes like you were saying.

Could try a Faraday Modesty Screen. Copper cage around the tube connected to chassis ground.

I have hundreds of tubes of many types including dozens of 6SN7s and 12SN7s. None are hummers in my Eufonika H5, G1217 Solstice or Vali 2. Some are a tad noisy because of age and use.

Some other types like FDD20 and GEC CV133s are very susceptible to RF and stray electromagnetic fields in any amp here. Those ones require a Faraday cage/shield to reduce hum/noise/celltower interference.

Chasing down weird noise is part of the charm of tube rolling. Not a charm that wears well over time tho.