This dac has the newish Delta Sigma type conversion, 1bit ,bitstream, and ESS are similar.
If you like that type of sound that is polite, smooth and easy to listen to, fine.
For Redbook cd I now prefer the old school R2R ladder multibit dac chips, which are a dying race because of very high manufacturing costs, up to 10 x of the Delta Sigma type dac chips.
A well implemented R2R Multibit dac chip has a "jump factor" that delta Sigma's can't get close to, but they need to be implemented well. Like the Metrum Pavane and Totaldac and a couple of others use, they are very expensive but you won't go back to Delta Sigma once you've heard it.
I suggest for the $11 parts cost for 5 you only need 4, to replace your tubes takes about an hour for a tech to do, and see how you like it.
Cheers George