OK, found my notes. The transformer is the BH-1, our first custom/proprietary Magnequest product. Spec is 8000:8 ohms. The core is M4, a higher grade of grain-oriented silicon steel than the usual M6. A few were made with nickel pinstripes. This is a parallel-feed (parafeed) output, so no DC current - it was used with the PC-2 plate choke which is a Magnequest BCP-15 modified with a smaller air gap for more inductance (50 henries at 40mADC).
I can't find any documentation of the lead colors, but my personal SEX amp has the upgrade installed. So I took down to the lab and found the standard colors were used - primary winding blue to plate, red to AC ground; secondary orange is positive to speaker, black is ground.
Topic: Question regarding Magnequest transformers (Read 155 times)