1874B auto mixer

[gortnipper]

Does anybody know what input transformer is in this mixer?

[whitebroncoii]

Is it a 1674B ?

[gortnipper]

could be - but the number looks like an 8 to me.

[gortnipper]

OK - it must be a 1674B - since the photo in this pdf for the 1674/1678C the 6 also looks like an 8.

http://www.greatplainsaudio.com/vint...LL_partial.pdf

[whitebroncoii]

The mixer picture is the 1674B Automatic Mixer. The input transformer is soldered to the input circuit board. It is a mu-metal, high quality step-up transformer that was used on the 1674, 1678, 1689, 1692 mixers. It delivers an additional 10dB of gain for microphone inputs. Channel 4 has a switch that reverses the transformer in the circuit for a line level input. They are difficult to get out of the circuit board . . .