(!!!) (Good Value Single) ECC81=12AT7 Mullard old logo made in Hyperlec Brive France used/good (8.4/9.8ma)
1 low noise tube) ECC81=12AT7 Mullard old logo made in Hyperlec Brive France used/good in white boxes 1970's (good in guitar amps and a "best value" 12AT7)
tested on Amplitrex
Good Ma range 8-10ma
Good Gm range 4500-5500
Mullard clone made in France
Hyperlec (later known as T.R.T and R.T.C.) was an electronics factory in Brive (a.k.a. Brive la Gaillarde), which is a town in the Corrèze region of France.