Connecting a DAC directly to an amp?


Do I need to insert a stereo preamp between a volume controlled dac (chord tt2) and an amp? Impact to sq?
emergingsoul
I run my Monarchy NM24 direct to the LTA Z10 amp; sounds better than with an additional pre-amp.
I experienced big improvement in SQ when my Teac NT-505 was connected to Modwright LS-100 preamp rather than straight to the amp connection. 
Modwright looks good.
Can tubes be off during ht bypass?
thanks

just read in manual that ht input can only be enabled via front panel and not remote.  Seems really odd.

No, tubes can’t be off during ht bypass on LS-100.  Since I don’t use the ht bypass at all I’m ok with ht bypass function on the front panel only. Otherwise it’s cool to have remote and trigger functions on LS-100... lot of high end preamps don’t have those  functions at all. 
@shkong78 
I connect Dave and HMS to Line Magnetic 508 pre input....It is working well....But I have Schitt Freya pre between Dave and my headhone amps to connect 20 ft balanced cables.
The Freya seems like a well-designed, simple preamp to provide high quality volume control with buffering or gain as needed between a DAC and a preamp.  I understand why you would use it to drive 20 ft interconnects.  Have you tried using it in your other system before the Line Magnetic 508 to compare whether it improves the sound vs. DAC-direct?  

I am curious because I previously thought I needed a buffer between my volume controlled Metrum Adagio DAC and my amplifiers but this weekend I rearranged my system so the DAC is close enough to the amplifiers that I can use 1M (XLR) interconnects.  At this length, it seems the buffer may not be needed for the same level of dynamics and tone although I am still evaluating.