Transformer pinout? (WTF is the primary?!)

BDSM · Post by **BDSM** » 21 Jan 2010, 19:52

Stupid question, but here goes...

I'm trying to use THIS x-former for impedance matching a mammoth clone's input (so I can use it w/my active basses) using Jack Orman's diagram as seen below, but using a 5k instead of a 25k trimpot based on the PC10k/10k's impedence.

My question is: Based on THIS INFO, where the hell is the primary on the pinout? (Which solder lugs to I need to connect to for the input, the CT, and the Output? I dunno if I need to use the CT, but since I have the switch I figure it can't hurt. Maybe it'll give a similar response to a soloed Jazz neck pick up but w/a more dynamic freq. response?)

Also, can I just use a pot or a trimpot instead of a switch (like a variable resistor) to select the impedance between the CT and the output of the primary, so I can dial in something more specific to meet my tonal needs? (Ct @ lug 1, primary output @ lug 3, & lug 2 into the input cap of the mammoth)

Anyway, can someone please help me figure this one out?
Thanks for your assistance.

dai h. · Post by **dai h.** » 21 Jan 2010, 20:09

in the diagram, the transformer is not being used as a transformer. It's being used as an inexpensive, easy-to-find inductor (in a pickup simulating circuit). A series VR should affect the impedance though I would think, increasing as the resistance goes up.

BDSM · Post by **BDSM** » 21 Jan 2010, 20:13

Yeah I get that part... I just need to know which lugs I need for my source in, center tap, and primary out in order to use the primary as an inductor.

dai h. · Post by **dai h.** » 21 Jan 2010, 20:41

okay. So if you are going to use the Xfrmer as shown in the diagram (if I'm understanding you correctly), couldn't you just use the continuity check or ohms function on a DVM to check for the connected lugs. Also on my Xicon (same maker *I think*) Xfrmer for my octavia clone (if memory serves) the pri. and sec. were marked with a "P" and "S", so maybe it's the same for your Xfrmer as well?

BDSM · Post by **BDSM** » 21 Jan 2010, 20:46

Ok I'll check for continuity. No there's nothing marked, and on the pinout on the PDF I linked there's only Positive input/CT/Negative input on one side, and Positive output/CT/Negative output on the other.

There's no info about primary and/or secondary to be found, hence my confusion.

BDSM · Post by **BDSM** » 21 Jan 2010, 21:10

OK, well I get continuity from + in to CT to - in, as well as + out to Ct to - out.

Still not sure which side to use for this tho. Does it even matter?

dai h. · Post by **dai h.** » 22 Jan 2010, 08:30

I'm not absolutely sure, but if you're using the Xfrmer as an inductor(one side only), I'd guess it doesn't matter. (Conversely, if it was being as a Xfrmer. I'd think it would--that is, there would be a difference in polarity of the signal.)