With the VH4 specifically, I have always liked 6L6 types.
It's been my main gigging amp since I first got it way back in 2002.
It came from Peter with EL34 BSTR , didn't like those tubes in it so I went on a mission trying a bunch of different types.
Finally settling on JJ 6L6 , and for many years and many quads , that's all I used.
I like the cool bias as well. , depending on the set.. around 56ma. More bias and they seem to be less defined.
Keep in mind these are my personal interpretations of the tone....
I use the whole tonal range of the amp, crystal clean channel 1 to smooth channel 4 lead.
However the majority of my time is spent on channel 2 and 3.
I think of the JJ's 6L6 as the best compromise of cleans and heavy sounds.
They're softer sounding than most other 6L6's but not dark or spongy as el34s.
There is nice harmonic content but it's not so overbearing that the cleans suffer.
They also have a nice upper mid percussion that cuts like a knife.
Recently I put in a set of TungSol 6L6GC STR, only because my last few quads of JJs
haven't lasted long. With them biased cold was better, around 45- 50ma.
They sound as good as the JJ's , only different.