FYI first thing to do with a Jolida 302a is replace the SED EL34's with Electro-Harmonix fat-bottle 6CA7's (another name for EL34, but don't get the EH EL34), and upgrade the Sovtek 12AX7WA's to one of the hundreds of better options.
I have no idea why SED EL34's have gained recognition in audiophile circles. They are a guitar amp tube, designed to offer enhanced Mullard-like coloration as an effect, not a good thing at all for hi-fi. The EH 6CA7's are a much more balanced tube. I've compared several EL34's in my Audio Innovations S500 (integrated 25W/ch Class A), including Mullards, SED's, and EH's, and the EH 6CA7 was a stand-out among the new production models and a revoltingly good value.
This is the type of thing that makes it so hard for tube newbies. The difference in performance and longevity varies so widely between tube brands, even between different vintages of the same tube model from the same factory. Learning the properties of different microphones is about 1/10th as inconsistent and intangible as learning about tube gear. It can be a lot of fun, or a very expensive source of frustration, usually a bit of both.
The Jolida recommendation is a good one though.