Need addition to my system

One of the best aspects of this musical hobby we all love is upgrading or adding to an existing system, making tweaks to what we already like and enjoy. I'm primarily an analog guy but will use streaming for longer/background listening and for checking out new albums prior to purchasing it on vinyl. I'm at the point of making an addition and would love to get feedback on the most logical next step. My room is small/medium sized (240 ft2). I'm currently working with:

- Dynaudio Heritage Special 2-way speakers

- Octave V80SE integrated with KT150 tubes with added Super Black Box and internal MC phono stage (very decent phono stage)

- Rega P10 with pre-mounted Apheta 3 cartridge

- Niagara 5000 and all Audioquest cables throughout (high-end mythical creatures power and speaker cabling)

My thoughts with respect to additions, likely in this order: 

1. Sub: REL Carbon Special OR JL Audio Fathom f112 (single one for now)

2. Separate phono stage: ModWright PH9.0x, PS Audio Stellar, Parasound JC3+ 

3. Cartridge: Hana Umami Red, ZYX Ultimate Airy X, Etsuro Cobalt Blue

4. DAC/streamer: Lumin T2

Please also recommend other pieces/products I should audition in these categories you think may mate well with existing pieces. Thanks for any suggestions!

Happy New Year as well to everyone!


Always treat the room before adding a subwoofer.  You may feel you no longer need one, especially in a room that small.

I was about to suggest a sub, but I think the size of the room plus Erik's wise general advice leads first to some room analysis. 

That said, what I see is a pretty hard to drive bookshelf with a tube amp and no sub. Then again, this is a very beefy, well made tube amp. So, I just am not sure whether you'd need or want a sub. 

If I were in your situation, I'd measure the room with the speakers and listening position in as many practical configurations as possible and see how the bass measured and sounded. In my own case, the best result was a combination of positioning, room treatments, subs, and some partial blocking of the ports on the main speakers. That yielded a near perfect bass response from 20-300 hz.