Quad of el84s and 6.6k OT

[studiodunn]

I built my Rocket with a 6.6k transformer. It is fairly high headroom and from what I've read the 5kOt would be more aggressive. Can I just speaker mismatch up to more closely simulate a 4 or 5k primary?

I also understand that an AC30 used 4K, an AC15 uses 8k so does that make pulling 2 tubes without changing the amp impedance fine?

[martin manning]

You could miss-match the impedance selector up one click (or the speaker down by half), to get 3k3 on the primary without doing any harm. Pulling two tubes would do the same thing, but you would have to double the value of the cathode resistor to keep the bias in line.