27-10-2012, 03:22 PM
That ECH35 and substitutes has just reminded me:
Seem to recollect that when substituting a mixer/osc with an ECH35 that attention has sometimes to paid to the metalizing as pin 1 on some valves have no internal connection so the manufactures use that spare connection on the valve base as a free tag connector ie: might have a voltage or signal on it, pluging in a externally metalized version would put the metalizing (pin 1) in contact with that connection.
Lawrence.
Seem to recollect that when substituting a mixer/osc with an ECH35 that attention has sometimes to paid to the metalizing as pin 1 on some valves have no internal connection so the manufactures use that spare connection on the valve base as a free tag connector ie: might have a voltage or signal on it, pluging in a externally metalized version would put the metalizing (pin 1) in contact with that connection.
Lawrence.
