I'm considering replacing my passive preamp with a tubes. Is it worth it?

The thing about a tube preamp is that the preamp is just the start of things. IME, you begin with which tubes to go with. I prefer the 12AX tubes. I have an LS15 preamp with modifications to the SS DC section, soft recovery diodes, better caps, as well as bypassing the caps in the audio section with Mundorf Silver Golds. Despite all the enhancements that made, it was still less than I wanted. Then I saw a little Chinese made 12AX7 based preamp at a place that sells things that Amazon either couldn’t or chose not to sell. It’s 12AX7s were broken, and some plastic covers off the rear pillars were missing, but it was perfect for me. It had a tube rectifier so I didn’t have to quiet the DC down to keep noise out of the low level details. In fact, other than rolling tubes, the only thing that I did to it was to bypass the large output coupling caps with Vcaps. Put in some Telefunkens and put a fork in it, you’re done. Not very versatile, but if you want tube flavor, it’s the way to go. My AR and Coda preamps are sitting idle. I should and likely will try some copper Vcaps in both preamps, but I think 12AX7s just have a bit more magic if you will, than 6DJ8’S do. So, 270 for the preamp 130+/- for caps, and tubes for what you can find them for, my source has Telefunkens pulled from test equipment, they test new and seem to last. YMMV

This is the preamp I now use;

https://smile.amazon.com/Nobsound-NS-01P-Preamp-Preamplifier-ALPS27/dp/B00LUCZLZQ/ref=sr_1_4?ie=UTF8...

I've actually gone from a tube pre to a passive. I used to own an Octave Audio Phonomodule. At the time, i thought it sounded good. That was until my mate brought his Dave Slagle autoformer TVC over. The difference was day and night. Soon after i built my own and have never looked back. I will never go active again. 
But as they say, it's all system dependant. 

A used  Rogue Metis preamp should be in your price range. For the price a nice tube pre with easy tube rolling. Have been using one for a year now and I'm very pleased with it.

amritash,
Congratulations on your new acquisition. Enjoy it.

Out of curiosity - what was your passive preamp?
Alternatively you could have purchased a Bluetooth DAC which has a healthy 2V out and kept your passive, if you like it's sound. You still should get a Bluetooth DAC, rather than connecting the iphone directly to the preamp.

Hey

So Ive received an have listened to the Audible Illusions modulus 2d.I am in love. I put inReflector 6H23p-EB / 6922There is absolutely no comparison between the Mod Squad Line Drive passive. The AI sound is just so beautiful. I think that I’ve finally heard the audiophile sound. I could listen to this and do for hours on end.
Now that I have been bitten I’m curious what I can do with an upgrade on it. The small thing that I would like hear is an improvement is the highs being a little more distinct. Imaging on the AI is great but I know there is better. Im considering some but I’ll post the question in a separate thread.

thanks
Adam