Grew a pair, and fired it up myself - Sluckeys plexi check

[pjd3]

I believe I figured out the answer to my latest brain fart.

If sluckeys schematic shows the NFB coming from the 8 ohm tap of an OT that is properly spec's out for 6V6's and an 8 ohm tap, then it goes to say that I should be providing the NFB from my 8 ohm tap as rendered by my calculations for a 6V6GT - regardless of the fact that this OT was chosen in its past life for a pair of "6L6GC's".

Its winding ratios that are calling the shots. Not paper diagram history!

Best,
Phil

[sluckey]

Did you notice the note on my schematic concerning NFB? Probably if my OT had a 16Ω tap, that note would not be there.

[pjd3]

Regarding the change from 100k to 22K? Yes, did notice. So to get this right, you may or would have left it at 100K if you had a 16 ohm to hook it to?

I also want to try to thing of this right along with getting it right.

I did install an adjustable NFB that will give me a range of around 16K to 86K. I really did want to see how it effects tone and just in case a little more NFB helps under more extreme PPIMV use.

So, it looks like I should be fine with it just like yours, the 8 ohm tap. The reason I got confused was that back in the old amp with 6L6GC's, the "8 ohm tap" was a different color!! if you know what I mean. I just got temporarily lost in the OT reflection translation.,

thanks sluckey.
Best,
Phil

[sluckey]

I did install an adjustable NFB that will give me a range of around 16K to 86K.

Well, in that case connect it to whichever tap you want. Let your ears tell you when it's "right".

There really is no right or wrong, just personal preference when you're not trying to clone an amp.

[pjd3]

Sure Sluckey, I get that. But I did want to at least start from the schematic as it was. If I find it leans one way or the other too much for taste, I'll switch taps. and I take it that the higher impedance tap gives more NFB.

Thanks you!

Best,
Phil D.