I’ve built the original Stereomour and the Kaiju....

[ebag4]

And I have determined my favorite of the two is the 2A3, as long as I am driving copacetic speakers.  My questions is are:

The Kaiju is a superior piece of kit vs the original Stereomour (no slouch in its own right)!

Will the Kaiju ever be moddable for the 2A3 tube?

Is the Stereomour II a significant improvement over the original?

Best,
Ed

[Alonzo]

Yes,
Only to the Stereomour I vs Stereomour II.    The other part is for the experts but with the new monoblock I would venture no.
Now for the I vs II, my one(s) are heavily modified and they are still a step below the II in background. Everything else will depend on your speakers and mods.

[Paul Joppa]

Of course research continues, but at present this is the situation:

Kaiju is impractical to modify for 2A3s, primarily because it does not have suitable power transformer windings - both filament and plate supplies are at too high a voltage.

Stereomour II in stock form is only slightly different from the original. They still use 12AT7s, to maintain enough gain for use without a separate preamp. But the quiescent current is increased a bit, and the bias resistor is unbypassed, both of which help. Other than that, it differs from the original mostly in its ability to be upgraded:

* The switched attenuator  as used in BeePre and Mainline can replace the volume/balance controls
* The drivers can be upgraded to have shunt-regulated power, as used in Kaiju. ()
* There is a DC filament upgrade, if you have extremely efficient speakers

The ultimate Bottlehead 2A3 is, of course, the new MonAmour, which uses much of the Kaiju technology, including shunt-regulated 5670 drivers and the much larger Kaiju output transformer/plate choke.

[ebag4]

Thanks for that Paul, I haven’t been around much of late, so I was unaware of the new 2A3 amp.  Perhaps it is time for a new build   .  Time for some research.

Best,
Ed