Which has richer tonality, the Holland e188cc or the USA 7308?

@pmboyd , have you tried a 6922 PQ Holland?

From Brent Jessee...
Fabulous original 1957 D-getter vintage white label Holland made PQ type Amperex tubes, and have the rare, indented glass midsections ("pinched waist")and wider bottoms that are famed for ultra-low microphonics. These 1950s pinch waist tubes are rarely found, since they are so fine most are in private collections and stocks!

lowrider57... Nope, only tried the 6922 PQ USA. I love its rich tonality but find it lacks the clarity and spatiality of the 7308 USA, which, unfortunately, is comparatively lean and edgy in my rig.

Amperex best sound great tube especially gold pins..

Hi,
tonaly rich tubes are Mullards, the E188CC 1960's is a great version also, very hard to find.
e188cc Holland = VR1 (D-getter 1960), VR3-VR5 (0 getter 1960-1963)
6922 USA = 7L6-7L8 (1961-1963)
Mullard e88cc = 7L1R (1962)....
Unfortunately with tubes is trial and error when not becoming noisy

Holland - period.

Also stick with E88CC/6922 if you want full/balanced mid-bass with less than a WAY full range speaker setup sans subs.

You might also look into current production (based on some online assessments).

I stopped using 6922 types 15-20 years ago, but acquired/listened to pretty much everything and sold in excess of 50 matched pairs as well as gobs of singles (some of them here on A'Gon, though Ebay was the main venue).

Don't know if stock is still floating around but Richardson Electronics purchased the Amperex namesake and their tubes could be ANYTHING (go by the etched codes or use a reputable dealer).

DeKay