[Ripper2860]

Cool! Any idea how old 'really old' is?

 

[Varejao17]

Cool! Any idea how old 'really old' is?

Not entirely sure, but some documentation suggests pre-1925...
https://www.radiomuseum.org/tubes/tube_t1_tkd.html

 

[ChrisPDX]

The 6SN7GTA and GTB versions were introduced in 1950 and 1954 respectively. They have ‘upgraded’ ratings, which are as follows.

GTA: maximum anode dissipation upgraded to 5W (the GT is rated for 2.5W)
GTB: identical to the GTA, but with a controlled heater warm up time for use in equipment with 600mA heater strings

This is significant because it means that a circuit designed around the 6SN7GTA/GTB cannot have 6SN7GTs substituted into it. Substituting a GT in place of a GTA/GTB in your equipment will precipitate its rapid destruction and possibly damage your equipment.

This last paragraph above (highlighted in red) is quite concerning.

My Schiit Freya+ shipped with Tung-Sol 6SN7GTB tubes.

Yet the owner’s manual clearly indicates: “Freya+ accommodates any 6SN7, 6N8S, or 5692 tube type.”

Am I to believe that Schiit is simply unaware that using a 6SN7GT tube in their Freya+ pre-amp — which evidently has a circuit designed around the 6SN7GTA/GTB tubes that they provided with it — will actually rapidly destroy and possibly damage my new Schiit pre-amp?

Surely Schiit engineers are not guiding their customers towards tubes that will destroy their products, right ? Am I misunderstanding what @adhoc meant ? Or is his warning incorrect ?

Thanks. I like this thing and do not want to rapidly destroy it by following its manufacturer’s guidance.

 

[JKDJedi]

This last paragraph above (highlighted in red) is quite concerning.

My Schiit Freya+ shipped with Tung-Sol 6SN7GTB tubes.

Yet the owner’s manual clearly indicates: “Freya+ accommodates any 6SN7, 6N8S, or 5692 tube type.”

Am I to believe that Schiit is simply unaware that using a 6SN7GT tube in their Freya+ pre-amp — which evidently has a circuit designed around the 6SN7GTA/GTB tubes that they provided with it — will actually rapidly destroy and possibly damage my new Schiit pre-amp?

Surely Schiit engineers are not so ignorant as to guide owners towards tubes that will destroy their products, right ? I am misunderstanding what @adhoc meant ? Or is his warning incorrect ?

Thanks. I like this thing and do not want to rapidly destroy it by following its manufacturer’s guidance.

None of those tubes ever reach to their max potential when used for audiophile purposes.. your good.

 

[tafens]

This last paragraph above (highlighted in red) is quite concerning.

It’s definitely something to be aware of and cautious about.

The 6SN7GTA/GTB is designed to handle up to 450V on the plates, while the GT is only designed to handle max 300V.

My Schiit Freya+ shipped with Tung-Sol 6SN7GTB tubes.

Yet the owner’s manual clearly indicates: “Freya+ accommodates any 6SN7, 6N8S, or 5692 tube type.”

Am I to believe that Schiit is simply unaware that using a 6SN7GT tube in their Freya+ pre-amp — which evidently has a circuit designed around the 6SN7GTA/GTB tubes that they provided with it — will actually rapidly destroy and possibly damage my new Schiit pre-amp?

Surely Schiit engineers are not guiding their customers towards tubes that will destroy their products, right ? Am I misunderstanding what @adhoc meant ? Or is his warning incorrect ?

Thanks. I like this thing and do not want to rapidly destroy it by following its manufacturer’s guidance.

The warning is absolutely correct, you don’t want to exceed the maximum plate voltage. Nasty things may start to happen if you do.

However, with the Freya+, as the manual states, you are good to go with any 6SN7 tube, which means that they won’t exceed 300V on the plates (or indeed the lowest voltage of all of the tube type that the manual lists, and probably go a fair bit lower than that, too, to conserve tube life).

it just happens to ship with GTB:s, probably because 1) they think they sound best, or 2) they’re easy to find in bulk, or 3) both

 

[Ripper2860]

Jason, Mike, and team are pretty smart cookies, so I'm confident that they know what they are doing. Plus, it has a 5 year warranty, so they must feel pretty OK with GTBs being in their gear seeing as they shipped it that way.

 

[bcowen]

it just happens to ship with GTB:s, probably because 1) they think they sound best, or 2) they’re easy to find in bulk, or 3) both

Exactly. Just because the amp shipped with GTB's doesn't mean it requires GTB's.

 

[JKDJedi]

Exactly. Just because the amp shipped with GTB's doesn't mean it requires GTB's.

Mr Bcowen here is the Schiit Magnet (meant that in a nice way) .. he'll set you straight.

 

[ChrisPDX]

Exactly. Just because the amp shipped with GTB's doesn't mean it requires GTB's.

Mr Bcowen here is the Schiit Magnet (meant that in a nice way) .. he'll set you straight.

Thanks all for the responses and reassurance that Schiit knows what they’re doing, as I had assumed, and that I will not destroy my pre-amp by following their guidance.

In a thread purporting to be an authoritative guide to 6SN7 tubes on an audio-playback forum, the unqualified statement quoted is at best incomplete, at worst misleading. I hope @adhoc will consider revising it to avoid raising unnecessary concerns.

Thanks again for the insights, all.

 

[bcowen]

Thanks all for the responses and reassurance that Schiit knows what they’re doing, as I had assumed, and that I will not destroy my pre-amp by following their guidance.

In a thread purporting to be an authoritative guide to 6SN7 tubes on an audio-playback forum, the unqualified statement quoted is at best incomplete, at worst misleading. I hope @adhoc will consider revising it to avoid raising unnecessary concerns.

Thanks again for the insights, all.

No offense, but there is nothing incorrect or misleading about @adhoc 's statement. Basically, don't put a GT in a component that is designed for the higher voltages of a GTA or GTB and therefore requires a GTA or GTB to function correctly. Any credible component manufacturer would make this requirement quite clear in the manual or otherwise. Every audio component I've ever used has been designed around a GT. I can use a GTA or GTB without issue of course, but they aren't required. Your Schiit was also not designed to require a GTA or GTB -- it was designed for a GT. Perhaps Schiit caused unnecessary confusion by sending yours with a GTB tube, but that doesn't invalidate what @adhoc wrote.

 

[ChrisPDX]

No offense, but there is nothing incorrect or misleading about @adhoc 's statement. Basically, don't put a GT in a component that is designed for the higher voltages of a GTA or GTB and therefore requires a GTA or GTB to function correctly. Any credible component manufacturer would make this requirement quite clear in the manual or otherwise. Every audio component I've ever used has been designed around a GT. I can use a GTA or GTB without issue of course, but they aren't required. Your Schiit was also not designed to require a GTA or GTB -- it was designed for a GT. Perhaps Schiit caused unnecessary confusion by sending yours with a GTB tube, but that doesn't invalidate what @adhoc wrote.

No offense taken. Now, I’m obviously not an expert on this stuff, but it seems straightforward to conclude that, given the audio-playback context of this forum, the unqualified declaration that “substituting a GT in place of a GTA/GTB in your equipment will precipitate its rapid destruction and possibly damage your equipment” is insufficiently complete, assuming of course that this forum is at least partly intended to assist relative beginners. Thanks again.

 

[bcowen]

No offense taken. Now, I’m obviously not an expert on this stuff, but it seems straightforward to conclude that, given the audio-playback context of this forum, the unqualified declaration that “substituting a GT in place of a GTA/GTB in your equipment will precipitate its rapid destruction and possibly damage your equipment” is insufficiently complete, assuming of course that this forum is at least partly intended to assist relative beginners. Thanks again.

I guess I wasn't reading it the way you were. But I see your point now. Perhaps it could be clarified into "substituting a GT in a component designed for a GTA/GTB will precipitate its rapid destruction and possibly damage your equipment."

 

[Ripper2860]

A most civil and enlightening last few posts. Thank you for exhibiting patience and civility while providing meaningful and knowledgable dialog. There was certainly opportunity for the OP to be lambasted with mean and unhelpful posts, but the high ground was maintained. Kudos to all involved. You have shown why this is such a great community.

Time for tunes.

 

[PoloJCP]

It’s definitely something to be aware of and cautious about.

The 6SN7GTA/GTB is designed to handle up to 450V on the plates, while the GT is only designed to handle max 300V.



The warning is absolutely correct, you don’t want to exceed the maximum plate voltage. Nasty things may start to happen if you do.

However, with the Freya+, as the manual states, you are good to go with any 6SN7 tube, which means that they won’t exceed 300V on the plates (or indeed the lowest voltage of all of the tube type that the manual lists, and probably go a fair bit lower than that, too, to conserve tube life).

it just happens to ship with GTB:s, probably because 1) they think they sound best, or 2) they’re easy to find in bulk, or 3) both

I don't have a Freya+, I only have 2 Schiit Lyr3, which according to Schiit's official website and manual that it takes "6SN7". I have used them with GT/GTA/GTB and without any issues at all.

 

[lostrockets]

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