KT 66 Plate impedance?

[Markusv]

Calling RJ or Fishy if possible

I am just checking over my KT66 rocket and the speakers it's matched with.
Currently I am running it into 16 ohms on what's supposedly a 16 ohm tap on a Judybox OT
The primary impedance on the OT spec sheet is given as 4000R if used with 6L6 or EL34

I am however uncertain of the plate resistance of each KT66. I run it Push pull (of course) at about 340 on the plates.
From what I can see each plate R should be around 4000 to 5000? Is this correct?
The reason for my uncertainty is that I see data for class A at 250 V, reflecting 4000R and then Class AB at far higher voltages with an Impaedance of 5000R

Suffice to say I'm confused and would sincerely appreciate help

Amp sound glorious BTW but I want to ensure it sounds glorious down the road.

Many thanks,

Markus V

[Structo]

I believe at 4K you are ok.

The plate voltage can of course change that rating but for overall use I think you are ok.
A 5K OT might be a better match but I don't think you should have any issues.

[rbryerton]

So, according to these snips from a KT-66 datasheet, I'm seeing that 5k-ish would be "ideal". If you look at the second attachment, you'll see that over a large range of of reflected impedance, the power doesn't really change too much, but the distortion really does. Lower impedance=higher distortion in this case, which can only be a good thing as this is a guitar amp!

Someone correct me if I'm wrong, but your transformer is fine for this application. Marshall JTM-45 ran the KT66's at a ~390 plate voltage, and the impedance was 8k. If you want to try that, just connect your 16 ohm cab to the 8 ohm tap. See which one you like better.

Either way is perfectly safe. Disclaimer: I'm just a hobbyist.

[Markusv]

Thanks for both the answers

I will see the difference between what I'm doing now-and the other alternative( seems more like the JTM 45 picture right now given the taps I'm using vs the speaker load)

Thanks though- I want to keep the beast in good health.

BTW my rocket is smack in the middle of ACDC country by the time it hits 11 o'clock with humbuckers
But back off a little to about 9 oclock or on the guitar and the cleans are loud and chimey!
My LP clone is too hot for it really- this thing shines with a strat. Then the cleans sty with me higher up the dial
I run a ramrod and a ragin' cajun at 16 ohms in a combo

Markus V