Tube recomendations for a newbie

I have just purchased a Mingda Mei Xing tube intergrated amplifier. I live in Shanghai, China. I'm new to tubes and the amp is supplied with Chinese tubes. I'm wondering if swapping tubes on this amp will provide better sound quality? If so, any recommendations? I believe the tube configuration is: EL34 x4(JJ)、12AU7 x2、12AX7 x2. The system will play mostly jazz, classical, reggae. Speakers are Wharfedale evolution 2 bookshelf speakers. Thanks...
I just today recieved a Grant Fidelity buffer made in China with two 6SN7GT Chinese tubes. The sound is nice. I would say if the tubes you have are quiet, then 'tube rolling' is just wanting to play around with your toys.
Searching out tubes can be fun and frustrating, as you really have to depend on the unknow quantity that you are buying OLD, often used tubes. My take on it is most small tube owners keep the best for themselves, and sell the lesser ones. I plan on using the tubes that came with the unit i bought.And only in the future, if i need tubes, will I buy more. One thing I am certain of, Chinese tubes are getting better, and they will be up there with the good tube makers, and perhaps wind up being the best of all!
I have found after trying many different brands of modern production EL34 tubes that the SED Winged "C"s provided, what I perceived to be, a significant improvement in my Shanling SP80 amps. Tube rolling with used or NOS tubes can be a hugh gamble as Elizabeth pointed out. If you decide to pursue tube rolling for the small tubes find a tube seller who has a long term reputation. Purchases from some individuals can be costly and many times not very rewarding.
I believe tube rolling can make a big difference in the sound of the component. Whether or not rolling the originals out of the Migda will be better or not, only you can decide.
I've had great luck with sellers here on A-Gon, as well as Jim McShane (google, you'll find him). Jim will help you get the right tubes for your amp and your preferences.
Personally, I would recommend you begin with the 12AU and 12AX tubes. Cheaper, and my experience has been that they affect the sound more (certainly as much) as the output tubes.
Have fun! This site has a lot of information and Joe reviews a lot of different NOS tubes. As Elizabeth said it can be fun and really frustrating chasing the best tubes. You may want to get used to the amp first and do some reading. It might also be good for the amp to burn in and make sure everything is settled. Maybe a few hundred hours? Then take a chance and see what you get
Thanks for all your good information. I will take a wait and listen longer approach before I start to mix and match.
"One thing I am certain of, Chinese tubes are getting better, and they will be up there with the good tube makers, and perhaps wind up being the best of all!"

I couldn't disagree more, Chinese tubes suck!
I have two Chinese amps.The Bada DC-222 integrated amp that came with stock 12AU7 Chinese tubes and a Shengya A10CS Hybrid Integrated Amplifier that also came with stock 12AX7 Chinese tubes
Both amps didn't sound good at all at first, then I replaced the tubes with some cheaper NOS ones and now the amps sound great!!
The Chinese are starting to make some really good sounding gear but they have a very long way to go in regards to tubes! I personally haven't heard any good Chinese made tubes as of yet, in fact I throw them away.
You don't have to spend a fortune to get some really good sounding tube replacements. You can buy some nice NOS 12AU7 GE's,RCA's, J&J's among others at very decent prices and as far as the 12AX7 tubes there are current production tubes that are really good like the re issued Tung Sols and Mullard's.

This came from the Pacific Value site that sells your amp.
We recommend that you leave the JJ blue tubes in there as these should
be the last to go.
Get rid of the stock 12AX7 / 12AU7.
Try the Mullard 12AX7s - these worked the best. For 12AU7s - try the GE 5963s or the Sylavania 6189s both of these tubes worked well.
Need more bass? Try the EH 6CA7s - very good tube for the money.
Tube rolling can be fun, and it can certainly make a meaningful difference. I do it all the time.

But it is a learning process and you must start with an objective, that is, after your unit is well broken in you have to be able to identify what about the present units sound you want to improve and identify which tubes is most likely to get you there.

Then you have to identify the tubes which can move your sound in that direction. BTW, I usually expect to get larger changes using power tubes and smaller, but more critical in the final analysis, from small tubes.

You are right to take your time! But start reading up on the subject by following the forums and seeing what users have to say about the general quality and tone of the available tubes used in your amp so when you do decide to move you will be reasonably well informed and have a good basis on which to begin.
Btstrg, our experiences are the opposite of one another. While I am not the biggest fan of Chinese amplifiers, as they sometimes miss on either design or implementation, among other things, I actually think the tubes have become quite good. In the majority of cases they're far better than the Russian alternatives of today in my opinion.

Not sure about the 12AX7 you had, but the Shuguang 12AX7B with triple mica are a definite best buy in my opinion. I did hear the previous version were pretty lousy. Do you know if you had the double or triple mica version?
Swapping tubes can give a different sound, but the opinions may vary on this. In my case i have had an overdrive tone with my amp.