6sn7?

[RestoredSparda]

Howdy. Is it safe to use the 12au7 to 6sn7 adapter in the Mainline? I have a bunch of 6sn7 laying around from my Lyr 3 and Crack I'd like to experiment with. Couldn't find any info on the internet regarding the Mainline.

[Larpy]

The 6SN7 draws a little more current than a 12AU7, and although I suspect the Mainline's PT can handle it, I don't know for sure.

But the 12AU7 is used for voltage regulation.  I doubt very much you're going to hear any difference tube rolling even within the 12AU7 family.

The Mainline does many things well, but its design doesn't lend itself to tube rolling.

[RestoredSparda]

I appreciate the reply! If it's safe I'd like to try anyways. I love to tinker even if differences are small to none.

[Larpy]

According to this thread
https://forum.bottlehead.com/index.php?topic=5332.15
you can draw no more than the extra .3A of current a 6SN7 will use in the Mainline.

So it should be safe.  But barely.

If you haven't experimented trying different 10uF caps in the Mainline, you should definitely do so.  I'm confident you'll hear more of a difference doing that than with tube rolling.

[RestoredSparda]

Thanks for the info! For sure, I'm planning on using the Mainline stock to see how it fairs, then I'll for sure look into caps. I've heard good things about the v-cap ODAM series.

Tubes are more of a curiosity since I have about 20 lying around. Since most folks say they don't change the sound much in the Mainline it's actually a bit of a benefit towards OCD tube swapping. Just leave it alone. Lol.