I had the very same annoying echo / delay, however on completely different hardware.
But I think the problem is not the hardware, but the Windows Audio Mixer in Windows Vista, 7, 8.
The standard mixer in Windows XP was easy to use, because it showed all the hardware. If something didn't work, you simply fiddled with the various sliders until it worked.
With the new mixer in Vista/7/8, MS tries to be smart and shows only what they think you might need ..
As usually, when they try to be smarter than the user, they fail miserably ..
PowerMixer from ActualSolutions is a mixer program in the spirit of the good old XP mixer, plus some nice bells and whistles. You can get a trial version here:
Windows volume control replacement - Power Mixer .
1) Where does the delay / echo come from:
If you activate the "Listen to this device" on the properties page of an audio input, the analog audio input will be digitized. That digitized signal is then routed to the output device(s), where is converted back to an analog signal.
This happens by software in the Windows Audio software, not in hardware !
Because converting from analog to digital and then back to analog takes time, the original signal is delayed.
Turn off the "Listen to this device" option to get rid of the delayed signal.
2) But then I can't hear the original signal anymore ?!?
Yes, but you still see the LEDs flicker in the "Recording devices" list. So its still coming in, just not getting out ..
Start the PowerMixer (link above) and check out the Tree Control that list all your audio devices with all their inputs and outputs.
There should be a node representing your Audio Card (or the audio chip on your mainboard). Below that, you should see two nodes, one for all output devices/connections, and another one for all input devices/connections.
Depending on your sound card/chip, the input devices will be listed under
both the output node and the input node. Select the input device (where your external mixer and microphone are connected)
that is listed under the output node and pull up its slider. Now you should hear your original signal without delay.
What you hear now is the direct analog signal routed directly from analog input to analog output - an therefore without delay.
This corresponds to the "Direct Monitoring" option of external audio interfaces.
3) Can I do this without PowerMixer ?
Depends on the driver of your sound card/chip. In my Realtek driver all inputs have a "Recording Volume" slider and a second "Playback Volume" slider as well. That second playback slider is the one you need. Maybe it has a different name in your driver or its missing.
4) Can I do this with the standard Vista/7/8 mixer ?
I have searched up and down all property pages and stuff in the standard Windows Audio software, but haven't found a way.
Update: See mancman's post with screenshots on page two. He found a way.
Maybe it depends on the audio card/chip specific driver. If the hardware doesn't support the direct routing path in hardware, the software can't do very much about it ..
As far as I know, all Realtek chips do support direct monitoring on the hardware level.
5) Another tip
On the "Recording devices" page of the Windows Sound Control Panel, right click the list. Activate the options "Show disabled devices" and "Show disconnected devices". Maybe a new input device will appear, on my PC it is called "Stereo Mix". This corresponds to the "What you hear" virtual input device on Creative Soundblaster audio cards. Maybe that "device" helps somehow ..
Do you still have the original computer where you had this problem ? Or have you already bought another one ?
Many PCs and laptops use the Realtek audio chips as on-board sound card. All these chips allow "jack retasking", which means you can redefine the function of all input and output connections. On my previous PC, I could redefine all six output connectors on the rear panel as Line-In connectors and use the chip as a 12 channel mono or 6 channel stereo mixer. On my new PC, only some connectors allow redefinition. The chip itself would still allow it for all, but the mainboard electronics between chip and connectors do not !!
Realtek has several reference designs for the computer manufacturers. They can save a few cent, if they stick to a simpler design that only allows 7.1 output for DVD playback. Cutting the nice jack retasking feature also makes the computer more idiot proof - but also less flexible.
However, some computer manufacturers still use the more complex reference design, which allows full retasking. Check out the documentation of your new computer. The usual default is retaskable front panel connectors and non-retaskable rear panel connectors, but some allow retasking of more or even all connectors.
Of course, an external Audio Interface is the best option - I am still not decided between MOTU AudioExpress, FocusRite Scarlett 18i8, FocusRite Saffire 24 Pro DSP, or the upcoming Focusrite Saffire 26 (which is still top secret, except for dealers) ..