I have a kenwood ka-94 and it still plays music but if I turn the volume up the speakers start making a popping noise and the speakers are not the problem so I need to know what the problem could be internally

SOURCE: guitar amp make large crescendo-like noise, loud pop at end.

Same loudness, no speaker? This sounds (no pun intended) like a filter capacitor shorting out. Open it up and VERY CAUTIOUSLY look for what is making the noise. Filter capacitors can eject hot stuff. Very dangerous.

SOURCE: amplifier will only put out "faint" music, etc, even when the volume is turned all the way up

This may sound silly, but please check to be sure that the tape monitor switch in not engaged. Update this if that is not the problem.

Dan

SOURCE: I use an azur intregrated amp 540A and a Azur Pre

I've never repaired one of these but I have an amp at home that makes a intermittent static "popping" noise that i'm going to put down to a dirty volume pot (control) that needs cleaning. I will also have to change some of the electro capacitors that have dried up inside which cause "shot noise". With the right lubricant (electrical contact cleaner, nothing else) you could take to lid off and spray a small 1 second blast into the hole of the pot and any other balance or tone control yourself but I would take it to the electronics repairer to get the capacitors checked over.
My theory only
Good Luck!

SOURCE: I have a Marantz 2270

This kind of problem is logical, if you have the "loudness" control enabled. Well, let me explain the situation. The loudness control is a function that boosts the lower and higher frequencies (the bass and treble) in low volume settings. This is useful because at low volume settings our ears are not so sensible at these frequencies, so the result is nice to hear. This boost (the loudness) stops automatically (at most amplifiers) at volume settings just above the middle of the volume control (to be more specific near the 1 hour setting of the volume knob), that's the point that you get this cracking sound. In case the audio source has plenty of bass frequencies the result is what you hear.
I suggest you to lower the bass boost potentiometer or disable the loudness control when you hear music at these volume levels. A good idea also is to disable the loudness control permanently and boost the bass and treble from the knobs as you wish. This will give you a sound near the original one although at the beginning you will feel the absence of bass (this is because the sound you were listening before has more bass).

In case of a problem or clarification or further details needed, don't hesitate to post me a reply before rejecting my answer.
If you are satisfied, accept my solution.

Thanks and regards
Stelios
direct FixYa link: http://www.fixya.com/users/technical114

SOURCE: When i am turning the power on at. channel 1 for a

Pictures would help a lot (of the circuit board)
You're lucky, you have a whole channel for reference!
This means we can troubleshoot by metering points at channel A and cross referencing them with what's happening on channel B (You'll need a multimeter and SOME skill, as well as a soldering iron, solder, desoldering braid and/or a desoldering pump)

When we find something that's way out of spec, we know we've found the issue, or at least something connected to the issue.
If you have an oscilloscope, we can trace the signal to the point that it stops.
If not, as I said, metering mirrored points should lead to the issue.