Re: Western Electric

vinyvamos said:

One thing that is puzzling me however is the split inductor to ground preceeding the grids of the second stage. Can someone more knowledgeable shed some light on this and it's purpose?

Click to expand...

This is designed to kill the thumps. A sudden decrease in bias of the input tubes results in positive thumps at the anodes. The split coil acts a s very low impedance because these thumps result in opposite flux in the inductor core. This inductor presents a very high impedance to voltages of opposite polarity and very low impedance to voltages of same polarity.

vinyvamos said:

One thing that is puzzling me however is the split inductor to ground preceding the grids of the second stage. Can someone more knowledgeable shed some light on this and its purpose?

Click to expand...

I just thought the coils low DCR allows fast discharge of the coupling caps but high impedance in AC terms as a load. The two coils are wound on the same core so it helps to cancel distortions, hence less thump. The Altec 322C is really a later remake of the 1126, almost the same circuit, employing the same kind of chokes.

directdriver said:

I just thought the coils low DCR allows fast discharge of the coupling caps but high impedance in AC terms as a load. The two coils are wound on the same core so it helps to cancel distortions, hence less thump. The Altec 322C is really a later remake of the 1126, almost the same circuit, employing the same kind of chokes.

Click to expand...

I believe I gave a pretty good explanation in the previous post. Two coils on a single core make a transformer. When two windings of a transformer are fed with currents that generate conflicting flux, they react against these currents.
The corresponding reduction in impedance is much more significant than the simple difference between AC impedance and DC resistance.