6SL7 alternatives?

[Cobra2]

I found this (chinese) 300B PP amp, using 6SL7 as first tube (and 6SN7 as driver).
But doing a drawing of the internals, I find the 6SL7 connected as one triode (both in paralell).
The 6SL7 has a touch much gain, so a 6SN7 does the job almost just as good...

Now, I was thinking, is there a single-triode (octal) 6SL7, or something between SL and SN, or would maybe a 6J5 be a simpler sollution?

Arne K

[Yvesm]

Take a look at 6EA7/6EM7.
OK, the large triode is a bit too beefy but it could easyly replace the half 6SN7 while the small section really loos like an half 6SL7.

Yves.

[jon_010101]

6SF5 and 7B4 are both pretty close to a single section of a 6SL7 or 12AX7.

[Cobra2]

Loctal would fit (w/adapter)...octal preferred, so the existing socket could stay.

I do not think this first tube needs any "drive", but will disconnecting one half do any unexpected changes? (in front of the 6SN7, that is the splitter/driver).

Arne K

[jon_010101]

The 6SF5 is octal. You can also just use half of the 6SL7.

[jane]

6SQ7 (~1/2 6SL7 + 2 diodes).

jan.

[Cobra2]

Originally Posted by jon_010101

The 6SF5 is octal. You can also just use half of the 6SL7.

This would be the simplest "upgrade", I think. But, since it has a tad too much gain, would a 6J5 (and maybe a reduction in feedback) do the job better?

Arne K

6SQ7 is interesting, but not in my collection (yet)...

[jon_010101]

If the 6SL7 is in parallel, using one section only won't change the gain. Both sections in parallel are likely important to allow sufficient drive for the 6SN7 stage. A 6SN7/6J5, however, would reduce gain significantly.

[aardvarkash10]

octal smooth and cheap as chips

[Cobra2]

My napkin drawings..:

Arne K

Coments, please