Friday, August 6, 2010

Which new 12ax7?Full Music,Electro Harmonix or EI

From left to right,Full music Gold pin 12ax7,Electro harmonix 5751 gold pin,Ei 12ax7
All new production 12ax7 tube.Ei had stop production and will be more difficult to get.

Full Music 12ax7.
A completely new design rather than follow the construction on famous NOS tube.Previously Full Music is more famous for the triode type of tubes like 300b and 2a3. Now this Company from Tianjin,China release a 12ax7 tube.

The first thing I notice is lower noise floor. I suspect this tube might be a good candidate for phono. I like the tonality of his tube and the imaging is good.Sound is balance. I don’t have any complain much for a new production tube.I tends to like this tube more than others in this group.Kudos to Full music.

Electro Harmonix 5751 gold pin.
This is a premium version from electro-harmonix, Russia
5751 is a close family of 12ax7 with a lower gain.
The song  presented with more “muscle” and imaging is bigger than my reference tube. High is a bit artificial.In tends to dislike this tube in my system.

Ei 12ax7
Said to have bought all the equipment and stock from telefunken.
This tube is said to follow the construction of Telefunken smooth plate.Ei tube is made in Yugoslavia
The Ei tube which I am  testing here is originally selected by Jadis for the JPS2 pre amplifier. The plate is silver colour(There is another version where the plate is black).
Music is presented with a lot of “air”I feel it is a bit over from what I used to be.Extended listening i feel it is more of some echo at the high.
No wonder in another setup where a system using Jadis JPS2 + JA500  when playing the cd "Jazz at the pawn shop"give me the best atmosphere feel.("pub feel").
On the vocal  the singer is presented much younger and the bass is not as low.

**Tube tested in my diy Marantz 7 and using telefunken smooth and rib plate as reference.I think the 5751 tube is not showing the full potential as the specification of 5751 and 12ax7 is different.My pre amp operating point is tune more favour of a 12ax7 tubes.
*Thanks  Wong Chai for the tube.