Haufe BV107(09107) wiring for 7:1 in KM84 circuit

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

iturnknobs

Well-known member
Joined
Aug 2, 2014
Messages
736
Location
Crystal Lake, IL
So, I am trying to  install this trafo into a KM84 circuit. I have tested primary tied together in series at 1.4Kohms. Each side of the secondary tests at 32 ohms. In order to have a 7:1 ratio I need to configure the secondary side to come up with 200 ohms as shown in the schematic from Haufe. I can come up with 32R(one side), 64R(both sides in series) or 16R(both sides in parallel). No matter what I do, I can't seem to come up with the "magical" 200R. Does anyone have any insight?
 

Attachments

  • bv107.jpg
    bv107.jpg
    56.6 KB · Views: 30
PRR said:
DC resistance is NOT audio impedance.
Is this a clue as to how to wire/connect it? Should I just connect the yellow/green leads together, having white and blue connect to XLR pins 2/3? I'm going to try this which should work with the lowest output configuration... Ithink.
 
> white lead of the secondary to pin 2, blue to pin 3.

AND strap green-yellow.

That is if you want "nominal 200 Ohms".

If you really want " lowest output configuration", use the connections for "50".
 
White to white(on primary side).
Green to Yellow(on secondary side).

white lead of the secondary to pin 2, blue to pin 3.

I have tested this wiring and it seems to be correct in this circuit.


 
I personally wired red to red and black to grn on the Banzai PCB. Before replying, I did some homework, "transposing" the Cinemag CM-5722 schematic to the Haufe BV107 schematic and I suspect I may have wired mine incorrectly. I think that it could be wrong as far as polarity is concerned, but both mics definitely pass signal and sound alike and rather good. Maybe someone else can comment about correct polarity wiring.
 

Latest posts

Back
Top