Pwr tube swapping, primary impedance check

[rooster]

So help me sort this out..

I have a Fender HPTT that has a MM OT (4/8/16 taps) in it designed for the Fender TR so let's assume the primary is 2K. If I want to run two 6L6s, and I keep the OT on the 4 ohm tap but load an 8 ohm speaker, the primary is seeing 4K.

Now, on to 6V6s (the amp can be adjusted via PT taps and rectifier tubes to deliver anything from 375-425 plate volts so don't worry about the plate voltage). Here's my question: If a pair of 6V6s are looking for an 8K primary, and a quad is looking for 4K, does the quad of 6V6s need exactly the same 8 ohm load (on the 4 ohm tap) as the pair of 6L6s?

And... If I load a 16 ohm speaker cab to the same OT running either a pair of 6L6s or a quad of 6V6's, would I change the impedance selector to 8 ohms?

And last question... If I run a pair of 6V6s using a 16 ohm speaker could I leave the OT selector at 4 ohms and expect to see an 8K primary result from the OT?

Thanks, I need some coffee now.

[martin manning]

That's all good, but it would be nice if you could verify the 2k primary assumption.

[rooster]

Hey Martin. Yeah, MM is so private about their OT info. However, if they are cloning the Twin Reverb OT then I'm confident the 2K is the number. Thanks for getting back on this, I appreciate it, Martin.

[martin manning]

The reason I wonder about that is that the Merc LP Tweed Twin OT Zpri is 8k (the only time I can recall that their site has yielded some useful info).

[Phil_S]

Go ahead and test the transformer for turns ratio:
https://www.radioremembered.org/outimp.htm
If the only low voltage source you have is the filament winding on your PT, that is a perfectly good source. Just disconnect the OT!