ECC81 Mullard, Philips label, Tk3, copper posts, half box plates V5 93

Description

Pair Philips and Philips Miniwatt ECC81 made by Mullard UK,  1965 & 1966

This is a pair ECC81 produced by Mullard in England. The date codes Tk3 B 5L2 & Tk3 6K3 indicate that both tubes are the same early Tk3-version and that the tubes are produced in 1965 and 1966 respectively. Both tubes are Tk3 however the tube from 1965 has one plate hole whereas the 1966 tube has three plate holes like the later VF3-version. Very healthy tubes with good specs; see test results.

The tubes tubes have a copper grid and halo posts.

Sonic

This tube type is highly regarded; I refer to the few threads on the web for more information. Excellent valve for the preamp section; low noise, very smooth extended highs, tight bass. Balanced and smooth sounding, recommended! These tubes have the typical warm, creamy and spacious ” Mullard sound!

Test results

Both tubes test NOS. The internal balance between the triode sections is excellent.

For test methods and factory specification read the tube testing page.

Valve 1 V109	Ia (plate current): Transconductance (Gm): Gas test, Shorts test:	10,2/ 9,9 mA       6,2/ 6,3  mA/V OK	=  NOS =  NOS
Valve 2 V110	Ia (plate current): Transconductance (Gm): Gas test, Shorts test:	9,7/ 9,7 mA 5,9/ 5,9  mA/V OK	= NOS = NOS

Where NOS is : Ia = 7,0 to 14,0mA, Gm= 4,5 to 6,5 mA/V.  (Telefunken factory specification see test page)

Short description