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About MChapman

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  1. Simple answer: YES, but is more important for lower frequencies. Here is the link to the quick explanation:
  2. Here is a quick idea: put a 9V battery in the unit and turn on the battery switch and test it. If the distortion goes away, I would lean toward a phantom power problem. If it still has the same problem, then it it something in the microphone.
  3. A PCC-160 could work very well picking up a choral group, if the accoustics and placement of the speakers offer enough gain before feedback. If the space is "wet-reverberant-sound-venue", then it may be better to use a boom stand mounted microphone to give bettter direct pickup without adding the room acoustics.
  4. There is nothing I am aware of that will do that with the microhpnes all connected. You could use a Fox and Hound to find the wires if disconnected, but will not work in circuit. One simple idea may be to use a small transistor radio placed close to the microphone to check and see which mic is picking it up. This could be hard to determine if you have multiple mics in ther same room.
  5. I looked back at some old notes to see if I could match your wire color codes, and had no luck. Here is the best I do with some older service documents. CM_200_assembly.pdf
  6. The spec sheet on the JRX 125 shows that it is rated at 500 watts continuous, 1000 watts program, and 2000 watts peak at 4 ohms. So running one speaker per channel on the XLS-802D will give you 800 watts. This is above the continuous but below the program rating. Assuming you are not clipping the amp input trying to get more power out of it, then that will be a good match, although the speaker can handle a little more power.
  7. The question now is are you going to be using the speakers as standard 8 ohm units or are they using the internal 70V wattage taps? If they are 70V, what wattage are they going to be tapped at?
  8. Dave, That is a very good question! Originally, on the MA-5000VZ, and then the MA-5002VZ, the amps were required to have Class 1 output wiring. However, according to our regulatory engineer, class 1 wiring is only required when the output voltage is above 300 volts. The manual was changed, but obviously, the back panel was never updated. Even our newer, bigger IT-12000 and MA-12000i units only require class 2 wiring, even though they are rated nearly double the output wattage. I hope this helps ease the confusion.
  9. Alright. It looks like it just a little confusion based on "terminology". First, the amps front panel crossover only gives from the crossover point and lower on channel 1, while the crossover frequency and higher goes to channel 2. Hence, channel 1 = "lows", channel 2 = "highs". If you are using an external crossover, you can make the channels whatever you want. NOTE: JBL generally wires the Speakons 1+1- as low fequency, and the 2+2- as high frequency. (look at the spec sheet for the SRX715 or better yet, look at the back panel of the speakers for pin out wiring) You are really looking at highs, lows and subs. That being said, if you do not have 4 wire speaker cables, you will not be able to get the signal from the amps to the speakers easily, if at all.
  10. Ray, If you use this speaker on one channel of the PT-2, you will have around 175-200 watt at 16 ohm in stereo mode. Remember, you will only be feeding this into one channel of the amp for the 16 ohm load. If you want to run it stereo, for will have to either get another cabinet, or split the speakers inside the cabinet. You will be best served by contacting the manufacturer of the cabinet to check on that issue.
  11. Ray, Can you give me more details on the cabinet so that I can assist you. If it is indeed rated at 16 ohms, what is the power rating on the cabinet? Do you only have one, or are you running more?
  12. The least efficient mode of the BCA mode amp is with very little signal, or none at all. To help with that, the K series amps are equipped with a sleep circuit that put the amp in sleep mode when the amp went 6-7 seconds without a signal above 30 millivolts on the original units. We had complaints that this was "too tight", so it was changed in late 1997 (after less than a years production) to have a delay of approx 56 seconds before going to sleep. The amp has a built in 115 microsecond delay, that allows the output mode to come on line before the signal actually gets to it, which means you don't lose any program material, unless it is below the 30 millivolt level. If your amp was built after November of 1997, it already has this update installed. You can find and read the 4 digit date code on the amp serial number sticker. To "decode" it, the middle two numbers are the month of the year, and the first and last digits are the year. So, 9117, would mean its built in November of 1997.
  13. Can you give me an direct email reply with the serial numbers on all your XTI amplifiers. This may be a problem that occured in some early unit where a capacitor did not meet its stated specifications and casued a number of different events to occur, just like you have listed. These amps where built before September of 2006. If these units are in that range, we can contact Mahajak about these units for you.
  14. The XTi series does have internal sensing of shorts and gives you a display on the screen. If it would continue to do that, I would first switch channels with the speakers and cables to see if it occurs on the channel 1 as well. If it does, that would be a good indication that something is amiss in the speaker, cable, or the combination of both. It does not have to be a "dead short" for the indication to come up.
  15. The pre-amps for the early PZM's like the PX-T, PX-18, and PA-18 have not been manufatured since 1987, and we do not have any around. I think the PZM-2.5 has an electronics module built into the base. If you contact me directly, I will send you an electronic copy of a data sheet for the unit.