Can tube amps give true high end bass?

NO they cannot on anything under 8 ohms

+++ No they cannot on anything under 8 ohms +++

Pray tell me why not?

The differencies are VERY noticeable even above 40 Hz.
I tried a system in my office:

1.PC as transport
2.Audio Note DAC 2.1 Signature
3.B&W 602 S3
4.Kimber VS8 speaker cable

Both with CAMBRIDGE AUDIO 640 V2 integrated SS amp,and with SET 300B MONOBLOCKS (2 x 9W).A/B testing for few hours.
Results - better than expected with every amp.BUT:

1. 300B monos had a better vocal,and treble and midrange alltogether.Which was expected,of course.
2. Bass - SS amp had more tight and more precise bass.Especially noticed in fast double-bass parts.More than depth,the bass SPEED was a problem for 300B.
Dynamic fast bass drum (double bass pedals) were significantly better with Cambridge amp.But these 300B monos
cuold be improved with better output transformer (which is the most important part for bass in SET amp).

This is why i plan to use SS monos on rear 12" woofer of my Silverline Sinfonia,as mentioned above in my post.Best of both worlds.

I think it's horses for courses. My choice for an amp if I was going to play Jimi Hendrix's Purple Haze would be SS. I'd want that woofer going out as far as it could and coming back and stopping when it should. I also have an original master of a jazz trio recorded with very expensive mikes and no compression. The bass sounds best with my SET. I hear much more detail which in that situation makes it better for me.

Can tube amps give true high end bass?

Let's assume the speakers are optimally set up in the room (bery few are). Also, that "hi end" bass means as close to the original as possible.
Given these premises, of course a tube CAN produce bass...

It's not primarily a tube vs. ss question. It's a matter of application.

Comments such as

I also have an original master of a jazz trio recorded with very expensive mikes and no compression. The bass sounds best with my SET

can make sense: the set offering very linear amplification (within its limitations) will obviously sound superior to a less linear amplification circuit...

Keep in mind that tubes offer the advantage of a (limited) linear amplification range, whereas transistors need some feedback to stabilise their operation.

The common misconception is that ONE amplifier, be it tube or ss should be called upon to amplify signals in linear fashion going fm dc to daylight, and drive a speaker, in turn expected to reproduce sounds from dc to daylight in a linear fashion...

In an ideal world, we'd have amps for mid-bass down and amps for the rest of the spectrum -- but we don't.

So of course we are ultimately left with the often frustrating task of having to try out infinite spkr-amp combos in hope of striking the magical set-up -- be it tube or ss.