Description
A once in a lifetime: Philips reference tube long plate July 1954
This is a very early ECC83 Philips tube made in Copenhagen Denmark. It has long plates, D-getter with square foil and copper posts.
This tube coded ΔH mCN is a very special one. On the tube the text “BRUIKLEEN NAT. LAB.” is etched. The Philips Nat.Lab. is the physical research and testing laboratory of Philips Holland. This tube has been used for reference purposes.
These long plates are the most sought after ECC83 valves. Much rarer than the long plate Telefunkens. Very healthy tubes with matching systems; see test results.
The acoustic properties of the early long plates are legendary and widely known. I refer to the many threads on the web for more information.
Sonics
Excellent preamp valve, low noise, very smooth extended highs, very good in phono stages. Balanced and smooth sounding with liquid midrange, recommended!
Test results*
| Code | Ia1 (mA) | Ia2 (mA) | Gm (mA/V) | Gm2 (mA/V) | |
| Tube 1 (V44) | ΔH mCN | 1,59 | 1,64 | 1,90 | 1,85 |
Tested for leakage and gas.
* Where 100% is : Ia = 1,2 & Gm = 1,6. Rating see Home Page.
* Please read our test notes !
Short description
| Tube type | ECC83 |
| Quantity of Tubes | One tube |
| Brand | Philips Miniwatt |
| Manufactured in | Copenhagen Danmark |
| Date codes | ΔH mCN (July 1954) |
| Construction | creases on the top of the bottle, copper posts |
| Getter Construction | D-getter with square foil |
| Print Condition | None; see pictures |
| Box included | new white box |
| Equivalent tubes: | 12AX7 |
| General test results | NOS |
