Perka hat geschrieben:My new tubes have been running for 60-75 hors and there is an signigficant improvement in especially the midrange compared to the chinesse tubes. I can now play loud without difficult voices become screaming like before.
Perka,
I am very glad for your improvement! So, you've got: 4 x JJ/Tesla ECC803S and 2 x Mullard CV4024 (Cryo?) ?
best regards.
PS: I'm using Mullard 6201(Millitary 12AT7WA) in my Jolida JD-100H in stead of 12AX7, they are amazing! RCA 5751 are very very good as well, less detailed but excellent! I changed also my Xindak PC-02 Power Cable for an hand-made friend "Siezien" from Belgium: what an amazing change!!!! unbelievable even on blind test!
To go further - but it is more expensive! -, I'm wondering if it would not be better to change 4 x 12ax7 and 2 x 12AT7 of your Lua Appassionnato (Doge 6201 I think), by black plates - "Command" double/triple Mica - RCA 5751/Gold Brand Sylvania 5751 triple mica Match Quad and a Matched Pair of black plates RCA 5965/6211/6201....
My reasons of choosing a smaller mu (µ/gain) in the same category of tubes (nearly same specifications):
- a higher Transconductance (S)
- then a smaller Ri = intern Resistance ( Ri = µ/S Kohm)
and sound more fluid, more musical in theory.
Tubes/Valves/roehren categories:
- 12AX7:
5751 have a mu=70 in stead of mu=100 for 12AX7/ECC83
- 12AT7:
5965 have a mu=47 in stead of mu=60 for 12AT7/ECC81/6201
6211 have a mu=27 in stead of mu=60 for 12AT7/ECC81/6201
CAYIN CDT-17A OAD&TS Full Discret OPA ver.2/VECTEUR L4.2 OAD-->full symetric DIY ampli class A-->Ellis 1801b OAD/JBL PROJECT ARRAY 1400
Headphone Ampli Cayin HA-1A-->headphone Grado Labs SR-325i Gold.