(!!) (Best Pair) E288CC=8223 Siemens Halske Germany rebranded Telefunken NOS 1970 (33.2/33.0ma and 33.3/32.5ma) 1-3% matched

1 low noise pair) E288CC=8223 Siemens Halske Germany rebranded Telefunken NOS 1970 (N6-0F=1970) same date codes

1 tube) 33.2/33.0ma Gm=20,500/21,000
1 tube) 33.3/32.5ma Gm=22,200/21,900

NOS Ma = 30ma

NOS Gm = 18,000

Tested on Amplitrex

(Specs: Vfil=6.3 Ifil=0.475A, Vplatemax=250V Pwattsmax=3.0)

Typical Operation:
Va Vg1 Ia Ra Gm Rk Mu
100 -1.5 30.0 1,400 18.0 350 20-25