Beschrijving
Early version of the Philips CV455 made in 1956 in Heerlen Holland
This is a rare early version of the CV455 tube. They are produced in 1956 in the Heerlen Philips factories. The tubes have a D-foil getter, a half box plate structure and copper grid posts, see pictures. Very healthy tubes ! The CV455 is a military specification of the ECC81, which means that this tube has stricter quality and reliability requirements than the standard ECC81. This often makes the CV455 a better choice for applications where reliability and quality are crucial.
Sonics
Note from the WEB: This tube is characterized by an impressive open “air” at the top end. The soundstage is large. The midrange is flat, and the bass is Impressively tight and accurate. These tubes have a fine sense of dynamics, and most are impressively quiet. I tend to think of them as accurate, and their clean, focused sonic image is astonishing. These are not “very warm sounding” tubes, and to some ears their lower of midrange warmth may be interpreted as transparent/bright.
Test results*
The tubes test NOS. The internal balance between the triode sections is good. The measurement data below illustrate that the tubes are in excellent condition; matched and internal balanced.
| Valve
V14 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
9,8 / 9,5 mA
5,1 /4,5 mA/V OK |
= NOS / NOS
= NOS / NOS
|
| Valve
V89 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
9,8 / 9,5 mA
5,1 /4,5 mA/V OK |
= NOS / NOS
= NOS / NOS
|
Where NOS is : Ia = 7 to 14 mA, Gm= 4,5 to 6,5 mA/V.
* For test methods and factory specification read the tube testing page.
Short description
| Tube type | CV455 |
| Quantity of Tubes | One pair |
| Brand | Philips |
| Manufactured in | Philips factory, Heerlen Holland |
| Etch code | Both tubes (Tk1) Delta 6G (1956) |
| Construction | Half box plates, copper grid posts |
| Getter Construction | D-foil getter |
| Print Condition | See pictures |
| Box included | Generic Philips box |
| Equivalent tubes: | 12AT7, ECC81, 12AT7WA, ECC801S |
| General test results | NOS |












