Mazda does not worth the high asking price and I've found the TFK very plethoric, homogenizing the bass. All the NOS square or rectangular getter 12AX7 are first class. I have the RCA 7025, that is excellent but bettered by the SYLVANIA 5751 sqare getter of 50's (both 3-MICA black plates). Distantly better is the TESLA E83CC "Frame Grid"!!! (only the yellow printed! NOT the white!) and over the top of them stands the black long plate, angled square getter MULLARD CV492KE. Problem is that these two are really very rare & pricey (over $400/pair). Unfortunatelly I've missed the BRIMAR CV492 and the SIEMENS E83CC triple mica when they were still available.
Beware the -unusually cheap- offerings of SIEMENS (they are fraud RFT!) and don't bother about the fancy EAT ECC88 Diamond (they are ordinary cheap TESLA! with a cooler & gold plated pins).
Beware the -unusually cheap- offerings of SIEMENS (they are fraud RFT!) and don't bother about the fancy EAT ECC88 Diamond (they are ordinary cheap TESLA! with a cooler & gold plated pins).