12AT7 Shoot-out(Oct 99)

Roy Tang wrote:

It may not feature in a typical 12AT7 shoot-out or among your collection of T7, but it sounds surprisingly good (yes I'm pro-European on tubes) on Matisse Atom partnering a Brimar 12AX7.

This tube (RCA Triple Mica 12AT7)has rusty black plates with lots of mercury. Like an average Yankee tube, it can be a bit edgy on top, but not as shiny as the GEC A2900 also featured in the shoot-out. Other than that, it scores high marks on most aspects, offering a natural, lively and solid sound which outperforms the Brits that featured in the shoot-out even on mid-band/male vocal area.

Here are the 12AT7 which I have also auditioned in the shoot-out:

Marconi black plates square getter with no getter support – Very smooth and almost grainless, can make you feel sleepy though

GEC B??9 (the mark is smeared) rusty black plates square getter -- The only one that comes close to the RCA triple mica in the shoot-out, slightly more relaxing but not as authoritative

Tim: That was a GEC B309. We have tried this tube before but it lost to the early A2900 and TFK ECC801S on the Matisse FLS.

GEC A2900 rusty plates tripble mica -- Fast and punchy as we all know, too exciting even if you are playing Jazz music

Tim: OK. We have found out in our previous tube party that there are actually 3 types of GEC A2900 -
1) double getter
2) later triple getter
3) early triple getter
And 3) is significantly better than 1) and 2). 2) and 3) are structurally completely identical and the only way to tell is to check if 2) has a "CV6091" code marked on the tube and 3) has a lot number <100.

Mullard ECC81/CV455 grey plates square getter -- Plenty of air and harmonics but things are overly softened, too much MSG I would say

Brimar 12AT7 -- Rare structure: triple mica with shiny black plates and a square getter sitting on a crossbar, rather old I suppose. Breathtaking soundstage and instrument separation, very commanding and powerful, can make you feel nervous though

Telefunken 801S -- It creates so big a soundstage but with so little flesh and blood to fill it up, total trash

RCA black plates square getter -- Lively but a bit forward and lean, better than the 801S though

The tubes are auditioned in the following system:

Meridian 508.24
Matisse Atom (with Brimar rusty black plates square getter no getter support as the 12AX7)
Audio Note Quest 300B monoblock
Focus Audio FS68

Tim: As mentioned, the best 12AT7 I ever tried on the Atom is the Mullard M8162 with gold pin. This tube is still available at Carry On and you, or your friend, really should give it a try.