Early versión/laboratoy prototype made at Siemens factory in Munich, Germany.

Printed with pre-acid or standard codification, Siemens Munich development facility code: 715183 , third batch, February of 1957.

Grey shield style anode, large flat support with disc getter.

This particular tube construction was made only in 1956 for research and laboratory purpose.

Extremely good sounding one.

Tube test very strong on common new values:

26,5/26 (15=100%)

Also tested free of noise, gas and microphonics.

Worldwide priority postage with tracking code: 19€

Will send as giift and 10€ value, save your money.

Any question just ask