Attenuator resistors causing drop in high frequecies. HELP!

I've just knocked up a quick monitor control, 2 rotary switches stepped from 900k - 18k, with the last step being a no resistor for full volume. The 'no resistor' setting sounds fine, but as soon as I switch in a resistor I loose some high freq.

I bought really cheap resistors, no name brand. All passive wiring.

Thanks in advance to anyone who can point me in the right direction.

Cheers
Chad

The problem is not the quality of the resistors, it's they are too high in value. In combination with the parasitic capacitance of the cables, it creates a low-pass filter that sucks treble.
It all depends on the length and linear capacitance of the cable. In the absence of more details, it is impossible to give a pore precise answer. What is the source, what is the load?
If I understand well, these resistors are in series with the load...correct? This should not be so. Your attenuators shold be wired as pots.

The source is my Digi 192 TRS. Tip of TRS goes to switch pole, then to the various resistor positions then to XLR and TRS outs, via some relays. The Input Sleeve goes straight to the XLR and TRS Outputs
The cable is Canare XLR cable.

How do I wire them as pots and use lower resistor values???

Hope this helps
Thanks for your time

.

Here's a quick scetch of what I've got going on. Any help?

Looks to me like you are just adding a resistance in series, not an attenuator at all. An attenuator is a dividing network, just as PRR has drawn. You effectively "tap" off some of the signal, exatcly as a potentiometer does, only not continuously variable. There are three connections on a pot, and your circuit has only two.

ok, where does the third connection go from and to?
forgive my noobility

Probably end up modifying to this design, cheers for the help!
http://i13.photobucket.com/albums/a253/slapback/passive_router_sch_rev_d.jpg

Hi,



  look at PRR's sketch. Signal goes in top left, and shield to bottom left, signal out is the pointy thing on right, shield to bottom left, just like a potentiometer. there are plenty of drawings that will show this basic thing. I  suggest you search!



      Andyp

Chad said:

ok, where does the third connection go from and to?
forgive my noobility

Click to expand...

Ground.