VK-55, VK-60, VK-75...

All three of these BAT amps show up with fair frequency on A'gon. There's a bit of a price difference, but not an enormous one, between the later E &F revisions of the VK-60; the VK-75 (which was the VK-60's successor); and the VK-55 (lowest powered, fewest tubes, but newest).

Can anyone which comparative experience differentiate between the sounds of these units? Whether the theoretical difference in outputs matters in 'real world' settings (e.g., w/ 89 or 90 db @ 1W speakers)?

I had a vk 60 then went to a vk75se. The diff was rather large...not subtle at all. bass control, extension, ditto on the top end, better imaging, better depth, blacker background. All around a better amp. It was a little leaner in sound...but still has a wonderfully fleshed out midrange.

I don't know if the extra power did it...I think it's just a better amp. Much better.
vk55 is basically a cheapened version of vk60. vk60 = vk75 for all intents and purposes. vk75SE is a different animal, and if considering a 75, the se is really the only one to bother with. vk60 is easily the best value of the line, no doubt. vk55 = answer to question no one was asking... aka how to get the vk60 made cheaper and in a smaller box.

I am curious how the VK75 would sound, honestly I love my VK60 but want a little more oomph & can't afford the VK75SE. I wish I could justify purchasing another VK60 but really can't. So, no sense bothering with a VK75? I find that hard to believe.
Fishwater...I'm sure the 75 is a little better. The 75SE is a huge step forward. What about a 60 to 60se upgrade? I've read around hear that the 60se and 75se aren't far off.

Also, have you put better tubes in your vk60? The front two 6sn7's are quite important and can really improve the sound. The other 6sn7's to a lesser extent. Also new 63ccb's every 18-24 months helps.

Power cords and isolation help on the bat amps as well.

I am more interested in the power upgrade over the sound. I just re-tubed the amp using NOS tubes in front as well as new 63CCB's.

I love the sound of the amp I am just looking for a little more oomph.
More power? Just go with a 2nd vk60. It'll also sound better...imaging depth, control... good luck!
I wish I could justify the additional expense of another VK60 but I really can't unless I just say screw it!