i salvaged the guts of a bass combo that was deteriorating.
i have access to some quality hardwoods and plan on building a box for it.
similar in size to the one shown in the picture.

my question is:

since this came out of a combo, the tube sockets were facing down, now they are sticking straight back. can i just leave it like this without any consequences?

i don't want to have to de-solder a bunch of stuff and drill holes to mount the tubes on top.

facing straight down is worse for a tube than facing straight back (horizontal). Go for it.

i salvaged the guts of a bass combo that was deteriorating.
i have access to some quality hardwoods and plan on building a box for it.
similar in size to the one shown in the picture.

my question is:

since this came out of a combo, the tube sockets were facing down, now they are sticking straight back. can i just leave it like this without any consequences?

i don't want to have to de-solder a bunch of stuff and drill holes to mount the tubes on top.Check the datasheets for the tubes used against the alignment of the tubes in the chassis. Most specify which way the tubes can be oriented. Because there are physical relationships between the components in the tubes, and they are typically designed to be used vertically (socket top or bottom typically irrelevant) placing them horizontally can have affects on performance, and maybe on reliability.