• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Siemens codes


2004-08-16 8:13 pm
Please, if there's a thread here on this already, direct me to it. I have looked but possibly not found the right search combination.

I've bought a cheapish set of used Siemens ECC88 tubes with the purpose of trying them out in my system to see if the sound works with it.

The tubes are grey plate, all GA1 "double crossed T" 1B. I read this as being GA=ECC88, 1=revision 1, manufactured by Siemens & Halske in Munchen ... BUT ... is the 1=to '51 or '61? The in-glass base numbers are 7, 10, 11 & 11. Is there a system to these in-glass numbers?

I imagine the revision would be the key to this but I haven't been able to find a guide to the years of production related to these.