Request for Assistance Building Passive Attenuator

[Henry89789]

I would like to build a passive attenuator so I can connect a Zoom H4N to a video camera. I found a description of an ideal passive attentuator on You
Tube. The circuit employs two 220k ohm resistors, two 200k ohm linear trim pots, a stereo cable, and a small piece of vero board. The description unfortunately did not provide sufficient details regarding the connections for me (with limited electronics knowledge) to figure out how to wire up the circuit.  I was hoping that someone here might take it as a challenge to figure out exactly how the components are connected and post a schematic showing how to do it. The H4N/video rig allows one to do interesting things with music and video. The You Tube video is at:   http://youtu.be/ilqcVjasVsI   (at about 3:00 mins to 7:00 mins).   Thanks for any help any one can provide on how to make the proper connections on this circuit.

[PRR]

There is a schematic?? She holds up parts etc.



Not clear what you want help with.

[Henry89789]

Thanks for the reply. Yes I've studied that carefully. That diagram shows only one trim pot and one resistor but her finished product shows two trim pots and two resistors on a small board with a stereo cable going in and out. What she is showing in the pic you show is not the complete schematic for her finished product. What I need help with is the complete schematic for the finished attenuator with two trim pots, and two resistors with stereo cables in and out? I can't figure it out. Thanks.

[PRR]

> two trim pots and two resistors

"Same for left and Right channel"

"From Aux Output" is where one cable connects; "To MIC input" is the other cable.

The continuous line from in to out is the Ground. In the cable this will probably be the overall shield, and probably common to both channels.

[Henry89789]

PRR:

Thanks for the reply. The stereo cable has a red wire, white wire, and black wire going into the circuit and the same coming out. She took a stereo cable with 3.5mm plugs on each end and cut it in half. Her diagram doesn't show enough wires and shows only one trim pot and only one resistor. When she holds up the finished attenuator one can see the white wires go to 1 and 3 of one pot; the red wires go to 1 and 2 of the other pot; the black wires go together but is there a jumper from 1 of the right pot to the black wires. It seems rather simple but I am not sure....

[Henry89789]

Here is a schematic drawn from my understanding of the video and the diagram. Does my schematic look correct? Which end of the cable should be plugged into the camera and which end into the Zoom H4n? Thanks. 

[slacker]

I don't think that's right. To build what's shown in the diagram you want the black wire to pin 3 of both pots and going to both jacks. The red wire from one jack goes to pin 1 of one pot, connect one end of the resistor to pin 2 of the pot, connect the other end of the resistor to the red wire from the other jack. Repeat for the other pot using the white wire.

[Henry89789]

I got it. Thanks. Now I see how simple it really is. But according to the diagram the black wire would actually go to terminal 1 of the trim pot, not 3 correct?

[slacker]

Could be, I can never remember what people mean by 1 and 3, it will work either way, the control will just work backwards if you get it wrong.
The black wire wants to go to the pin that the wiper touches when turned all the way anti clock wise.