Tube FX Loop

[Kappa]

Hi I'm new in the forum and I don't know where I can post this question, hope the moderator will move to an appropiate section of the forum

I want to build a stand alone preamp, this is the schematic I want to use

the problem is this

As is the preamp is usable to be connected directly to a Power Amp, but the output impedance isn't adequate as pedal driver or with long lines, so I was thinking to add 1/2 of an FX Loop circuit, the send section, I think that way I can solve my problems

I've two way I can go, Tube or SS, about Tube I can understand also if my knowledge isn't perfect, about SS .......... ...... I think you've understand me

So I was thinking to use only the send circuit of this Tube FX Loop schematic

But doing that something that I don't like will happen, an unused triode of the 12a*7 tube

Yes, I know, I can use a 6av6 tube, but it is difficult to find one quickly if you need an urgency spare part, 12a*7 tubes are much more easily available

So I was wondering if there will be a useful use for the spare triode, and I've think if it will be possible to use it in parallel with the other triode of the same tube giving a better output signal to the line output

What do you think ?

Any council will be highly appreciated

Thanks

K