tube pre amp or tube amp

Wahoo, I would do neither, you would get far better results upgrading to a much better digital front end. 

Your  ARC CD 9 is showing its age vs newer digital front ends which will uncover more information and present a more realistic soundstage.

You will be shocked at the overall improvment you allready have an excellent set of electronics.

Other things you can do to improve the system is to use Critical Mass Centerstage footers they difference they make is shocking, you will get far great image width, lower noise floor tighter bass and greater dynamics.

Our philosophy is to tackle the weak points in someones system. and your digital is five years out of date. 

You can go to a much better CD player, a CD player Dac, a pure Dac, you would be amazed at the improvements by adding a digital server and moving into modern streaming. 

You can always reach out to us if you want further information

Dave and Troy
Audio Doctor NJ

I've always enjoyed a tube pre with ss amp combo. I run less efficient speakers so the ss amp makes it easier to drive them.

Previously I had a VAC Renaissance 3 and a VAC PA100 upgraded to a phi front end.  I first changed the power amp to an Ayre VX-5/20 and then upgraded the Pre to the current VAC Renaissance 5. Really enjoying this combination.

i’m a little different in that i have found that a great solid state preamp driving a great tube amp is very special. whether right or wrong going this way adds tube magic as the last link. 
the are many ss preamps that fit the bill and often have better features. fwiw

Hi

I thihnk the person who said, glass pre plus SS power has a certain something is on to something there.

SS power does develop better bass than will tubes.

I've been in the process of discovering myself. for some eyars now, and when I get the notion I need to change something I really enjoy 'as is', somethings up besides sound quality. as said, change for the sake of change points elsewhere. not at the system.

the second astute point made was about the apparent sole source, the CDP.

I've been all about the source being the key to any outfit. the better or deeper into those waters one can get, the better.

transports just do not age well or last forever. along the way the resolution slowly declines and one gets used to that sound as it dies. replacing it holds a whole new bag of worms waiting for it to break in!! I went thru that with a Sony XA 777 SCDP.

given the orig Q, I would say....

If at all possible put some $$$ into a DAC which gives you options with more sources and formats, and an upgrade or update path from the maker. 

Or... 

don't trade or sell off something to buy another something given you enjoy what you have now. simply wait a tad longer and 'add' a new piece to the existing rig.

having on hand a second preamp, or amp of differgin topologies and or brands is always an outstanding option.

if a DAC is not the top choice, I'd go in for an SS amp. great bass does so much for the things residing above it, its nearly a 'must' have thing for me to dig a rig.

of course, there are other areas where one can pitch money and as such, improve or re-arrange one's SQ. Isolation. cabling. racks. Room acoustics.

all that said, I do dig where this is coming from completely.

I finally had put together the best sounding rig I'd ever owned and then sold it off just to try an all tube affair. that one turned out just as good but in a different sort of manner. 

for me to be able to have no further arguments on which this, or what that, I need two separate rigs. one all tube, and something else.

... but that's just me.

good luck