Two mics into the same quarter-inch jack will not work. This creates a horrible impedience mismatch that essentially renders both mics useless. Granted, there will be sound generated by the mics, but you must keep in mind that Ohm's Law comes into play here. The mics are essentially made using a moving diaphram with a coil beneath it. That coil of very thin wire has a resistance, which is halved with another similar coil is placed in parallel with it. Consequently, the impedience of the mics, when in parallel, is divided by two, thereby overloading the input device, which in this case is the vocal processor.

I agree that most onboard vocal processors are sub-standard when compared to stand-alone , MIDI-controlled, vocal processors. And, while the effects such as reverb, echo, delay, are just fine, the harmonies leave a lot to be desired. That's why I have a pair of Digitech VRs (one for back-up) and use it whenever possible. As Dave, and anyone else who has used the external processors will tell you, there is no comparison.

BTW, I don't have a powerful voice, therefore, when I use either the onboard or external processor, I don't usually have a problem. However, I did try to mimic the problems using the PSR-2000 and 3000, and both will distort using any mic if the volume is turned up too loud, or if you put the mic real close to your lips and sing extremely loud. The mics I tested were the SM-58, Sennheiser 855-E, Crown CM311-A and Samson Q7. The same mics plugged into the Digitech VR performed flawlessly using normal singing levels. However, if you crank up the input level and sing loudly into the mics using the VR, it too will distort. Dave's statement about voice control is right on the money.

Hope this is of some help to those experienceing problems,

Gary