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previous: Tony PA amp schematic -- 2/9/2001 2:30 AM View Thread

Bogen output transformer?

2/13/2001 3:17 PM
D. Hiatt Collins
Bogen output transformer?
I recently got one of these too, to get my feet wet before I dive into the 5E3 project I'm planning. I've started to draw out a schematic, and it has helped to have the schem of another Bogen amp (the CHB35A, from to look at, since there are similarities in the way the circuits are laid out. I haven't seen a schem for this amp posted on the web, but I could send you a copy of the one I'm drawing when it's done.  
My question for the group is this: I'm having some trouble figuring out what to do with the output connections. There are 3-pin speaker connections, which I've never seen before. One pin connects to ground, another connects to a '70V' supply, whatever that is, and the third connects to the impedance selector strip. These connections are labeled on the back of the amp. The thing I don't know is how to hook up this 3-pin connection to a speaker. I've soldered wires to each of the pins on the inside of the connector to try things out, and I've been able to get sound with the 70V and ground hooked up to the speaker, but with no other combination. Adding the impedance connection into the mix doesn't seem to do much, or at least anything that I can hear through the speaker. No sound at all comes out when either just the impedance selector connection and ground are hooked to the speaker, or the 70V and impedance selector. The impedance selector strip has connections for Ground, Common, 4-ohm, 8-ohm, 16-ohm, and 25V. Any thoughts?

Greg Z Hi DJust hook you s... -- 2/13/2001 7:19 PM