Losing volume on channels

About the only thing that could make noise is the cooling fan. Does it sound louder when you've just hooked up and started charging the batteries? When you've got a lot of things drawing 12v DC power? Only other noise might be arcing by a short circuit or crackling of a fire!! ;)

First unplug it. Sounds like you need to spray some tuner cleaner in the pots that are crackling. Pull the knob off and you should be able to use a spray can of tuner cleaner with the straw that comes with them to spray into the potentiometer , then rotate the pot several times while it is still wet. After cleaning them all, wait 10 minutes and then try.

If you hear it with the sound off something is arcing, if not a sound problem.

Hi Jermaine,

It transmits, but no receive, are you sure, have you tried playing around with the volume control?

If, so did that make any crackling noise? If so, then this is due to lack of use of the volume control, many radios, including the old transistors with dials, would make crackling sounds when you adjusted the volume, and as I say, this is due to lack of use, So if this is the case and to get your receiving, turn the volume control up & down fully for a few minutes and while doing so your radio might receive a transmission that will be loud, quiet, loud, quiet, etc., as you play with the knob.

Keep doing so until all crackling has disapeared.

Do this often as possible when firing up your radio for the day, the more use these controls get, the better.

I hope this has answered your query.

Cheers,
Peter

There is a chance that a common control may have developed a high-resistance or 'dead' spot and is causing your symptom. Turn the POWER OFF and operate every control throughout its range a number of times, especially rarely-used ones like Tape Monitors and the Mute control.

If it still doesn't work you might want to prove if its a low-level signal loss or a high level amp failure.

One way would be to run an RCA cable pair from the Tape Out to any other device (even a TV with speakers) you might have that accepts an audio input. If IT can't detect receive the DEAD Channel you're losing it in the preamplifying or source selection stages.

If it CAN be played externally, the receiver is losing it on its way to or at the amplification stage. Further isolation would require hands-on technical expertise.

Using a common lead pencil, gently tap on the smaller tubes in the unit, listening for noises and crackling to change and the drive channel changes.

It is normal to get a slight twang when doing this from the microphonics of the tubes, however, the crackling and up and down volume points to a bad tube.

I have a Korg C-15s and also experiencing loud crackling sounds when I turn it on. The problems seems to be either the sliding volume control or the amplifier itself. Honestly though, I believe the issue is the volume control. I opened my piano to get a closer look and attempted to clean the contacts on the volume. Unfortunately after cleaning the contacts, the crackling sounds became somewhat worse. After I turn the piano on, the volume control is generally rendered useless......volume set to low volume and the noise is quite loud and other times the volume control is set high and get very low volume crackling noise. No real consistency. The noise does diminish after a few minutes but so does the piano sounds to an inaudible level. There were a couple of instances where I turned it on and surprising enough, no no noise and perfect sound. For these reasons I believe the issue is within the volume control and not so much the amplifier. I have an electronics background and noticed that the volume control is very unique in design and is not something that can be substituted with another volume control from other sources.

My recommendation is to check the sound quality of the audio from the RCA L/R audio outs on rear of the piano by connecting to a stereo receiver. If it sounds fine you're in luck. If the crackling sound does not diminish after a few minutes like mine does, I would suggest disconnecting the internal speakers and using the audio out only. You can connect a pair of studio monitors or high quality computer speakers, preferably with a small subwoofer to deliver the full audio range and deeper tone of a real piano. I'm currently using a basic pair of Logitech computer speakers and is quite acceptable until I can afford a high quality set of monitors or relocate my piano closer to my high quality Yamaha receiver.

I hope this info helps a bit.

On remote control before you shut off yor receiver press "TEST" button to save the memory. It will save every setting. Make sure to do that all the time after you change the setings.

Generally, crackling noises come from anyplace there is a mechancial connection for the sound signal. The volume control, main/remote speaker switch and possibly the headphone jack. That is where the contacts must be cleaned, but it requires dissassembly. Try operating the main/remote speaker switches, and plug/unplug a headphone several times. I am assuming there is still audio behind that crackling. Are you using both main and remote speakers simultaneously?

open it up and spray it with contact spray. move left and right and then spray again. this will normally do the trick. the crackling noise comes from standing in the same position for to long.