Description
Pair: Philips long plates made by Siemens & Halske in München
This is a pair very early ECC83 tubes. Produced by Siemens & Halske in München Germany. They have long plates, small o-getter and copper posts.
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.
One tube is branded Philips Miniwatt, the other tube has no readable print. This second tube has the PH LAB etch code which means that is was a reference tube of the Philips physical lab in Heerlen.
Sonics
Excellent preamp valve, low noise, very smooth extended highs, very good in phono stages. Balanced and smooth sounding with liquid midrange, recommended!
Electrically and Physical Matched Pair with NOS specs
Test results*
| Code | Ia1 (mA) | Ia2 (mA) | Gm (mA/V) | Gm2 (mA/V) | |
| Tube 1 (V49) | #4 mCP | 1,1 | 1,1 | 1,5 | 1,5 |
| Tube 2 (V50) | #Y mCP | 1,1 | 1,1 | 1,6 | 1,6 |
Tested for leakage and gas.
* Where 100% is : Ia = 1,2 & Gm = 1,6. Rating see Home Page. Test method see Category Page.
Test methods are outline on the Tube testing page, for test conditions see Category Page.
Short description
| Tube type | ECC83 |
| Quantity of Tubes | One pair |
| Make | Siemens & Halske |
| Manufactured in | München Germany |
| Date codes | January June 1956 & July 1955 |
| Construction | creases on the top of the bottle, copper posts |
| Getter Construction | Small O-getter |
| Print Condition | poor; see pictures |
| Box included | new white box |
| Equivalent tubes: | 12AX7, ECC803S, 12AX7WA |
| General test results | NOS |
