Belles 21A upgrade

I have a pair of Phillips Jan 5418A never used, are they better than the stock Mullards if the unit comes with Mullards?

Wig

the stock tubes in the belles 21a are mullard cv-4003 i believe.
here is a link to thread discussing tube dealers.
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1239836974&read&keyw&zztube=dealers

I opened up my 21A last night and found out their not Mullards but GE6189/12AU7A. Are these any good!

Wig

My preferred variant is the GE 5814A BLACK PLATE from the mid 1950's. IME though with your pre-amp, you will only get so far rolling the tubes. In order to make it sing, parts need to be upgraded.

How good are these tubes?

you have a solid state amp, so a warmer 12AU7 might be preferred

best in order
all are nice, smooth high end 12AU7's

2 low noise pairs) ECC82 Mullard branded Philips NOS 1964-1969 in Philips boxes (recommended)
1 pair $160) 11.8/12.2 and 11.4/11.6ma 1967 and 1969
1 pair $160) 11/11.8 and 11/11.2ma 1964 and 1966

1 platinum low noise pair $150) CV4003=12AU7WA Brimar NOS in original boxes 1974-1975 1-5% matching, boxes moisture damaged
1 tube) 12.2/12.5ma 1974
1 tube) 12.5/12.7ma 1975

Low Noise Platinum Pairs $125/pair) CV4003=M8136=12AU7 Mullard "Box Plates" NOS copper grid posts 1982-1985 most in original boxes

a 5814A could be used as a sub

1 platinum low noise pair $150) JRC-5814A RCA black plates double mica 1962-1965 original boxes (best pair)<-------
1 tube) 12/12.1ma
1 tube) 12.2/12.4ma

Thanks,
Wig