Annoying buzz produced from all monitor/line-out jacks
I bought a used (though claimed to be untouched) 2488 about a month ago, and me and my guitarist have been trying to figure out how to eliminate a buzz that comes out of our monitor source no matter which output we use. We've tried a couple power amps (an older Sony and a newer Pioneer) and both of them buzz. I don't believe it comes from within the machine because headphones are completely silent. Anyone know how to get rid of this or where I should send the machine to fix it, or is this beyond repair?!
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Assuming you are talking about your monitors for your 2488, the first thing I'd do is to consult the manual for proper placement of the monitors relative to the 2488. A quick rule of thumb is to place the monitors at ear level to the left and right of the 2488 so when you sit facing the 2488 yo will have one monitor facing each ear essentially. Again, consult your monitor manual as it will show the best placement and don't worry about electrical fields, etc. I have my monitors to the left and right of the 2488, the 2488 in the center and a 21" flat screen computer display in the center of all that with no problems whatsoever. That is the accepted practice generally speaking. Hope this helps.
There are 8 inputs on the back. 4 of them support XLR type microphone connections, but also double as 1/4 inch and the remaining four are just 1/4 inch. These are all line level inputs and you can use any of them for a keyboard hookup. Typically you might leave the XLR inputs (A thru D) available for mics and take the next two (E and F) to use from your keyboards L and R outputs. Then just assign those inputs to two adjacent channels (tracks) or one of the stereo pairs, turn up the input levels for those inputs and the faders for those tracks and you'll be able to hear the keyboard playing through the 2488 (or whatever monitors/or stereo you have hooked up to it for monitoring). To record the keyboard simply arm whatever tracks you have those inputs assigned to for recording and record away.
MIDI only carries digital information, not audio. Midi is used to communicate patch settings and note value information. If you want the recording to know the note value, then you should use midi. This is useful if you want to do things like adding rythm tracks, etc.
If your keyboard has audio/line out (as opposed to headphone out), use that, as it is matched much better in impedance. If it doesn't have audio/line out, then you can use the headphone jack, but you will have to turn the attenuation way down because the headphone jack impedance is much higher. This will tend to distort on the recording if you are not careful.
The first thing to know about digital recording is that distortion is much more of a problem. I won't get into the theory of this, just know that impedance mismatching is more of a problem with digital.
You can plug a mic into the front H input on the 2488, but depending on the type of mic you may get a weak signal. The typical voice mic is low-Z (low impedence) and the instrument input (H) on the front of the 2488 is High-Z. A high-Z input is expecting the relatively higher voltage put out by a high-Z mic (or passive guitar pickup). On the other hand there are high-Z mics out there and most computer mics are high-Z. These produce the voltage that a high-Z input is expecting.
If however your mic is low-Z you will get a weak signal on the high-Z (front H) input on the 2488. You should in this case connect an impedance matching adapter between the mic and the input. It steps up the voltage of the mic, giving it a stronger signal.
To tell what impedence (Z) you mic is use the following to match the rated ohms on your mic with the impedence:
low-Z = 150-300 ohms
medium-Z = 600-2000 ohms
high-Z = 10,000 ohms or more
If you already have a high-Z mic you can plug it into the front H input directly. For a high-Z mic plugging it into any of the other low Z inputs on the back will produce a distorted signal.
Repartition and format the hard drive. There are specific instructions elsewhere on the Internet. I did this about six months ago. I believe my problem came about after I stored my 2488 on top of my monitors - I believe the exposure to the magnetic fields corrupted the boot partition on the drive.
To reset the 2488 to factory defaults: Simultaneously press quick routing/shift/send/shutdown & turn on the unit.
The 'stop' button problem may require a look under the cover to see if the button is dirty or damaged under there. A good cleaning might do it. As for the 'no guitar out the monitors' issue, this sounds like it might have something to do with the setting of the monitor selector. Make sure it's set to 'stereo' and not effect loop or effect send or even muted. You might want to also make sure your monitor level pot is working properly.
In the monitor section on the 2488 console (upper right) make sure your monitoring source is set to 'stereo'. Then make sure your 'monitor level' control is turned up. The 'stereo' fader (sub mix fader on the MKI, stereo fader on the MKII).