Not sure what tubes you have but I have played around with some tubes. The Decware EL 34’s came stock and after 20+ hours time they sound really quite good for inexpensive tubes (look like red label Psvanes). Do prefer my pricey Mullard El34 ‘60’s xf2’s and RCA 6l6GC 1960 black plates.  The rectifier I replaced with a Sylvania 5U4 USN Tall bottle ‘50’s D top getter.  Great inexpensive tube.  Also liked the RCA ‘58 5R4GY ST bottle.  The  Russian red tipped 6H5n driver tubes did not sound very good.  Replaced with Russian Voskhod 6H23n ‘74 and French Philips RFT E188cc’s ‘65.  Both fantastic!  VR tubes I like the Westinghouse OA3 ‘67, Hytron OB3 ‘52, RCA USN OD3 ‘50’s.