The MX-160R is a powered mixer amplifier manufactured by the TOA Corporation of Japan. The TOA Amplifier, also called “TOA Amp” provides 120 watts output into an 8 Ω speaker, and a maximum of 300 watts RMS into a 2 Ω speakers.
The mixer provides six input channels and each channel has a three-band equaliser.
This is just an article diary to describe how I get myself into trouble by doing kind deeds for people.
From my Boss
There was a loud knock on the door, and I hoped it would not be Father Clarke. Luckily, it was the postal courier with a very large crate for delivery. From the looks of the crate, it seemed as if it had come from abroad.
"I've got to drop this on your floor!" The deliveryman growled, as he carelessly dropped the box on my nice laminate floor scratching it.
"Sign this!" He ordered.
"Sure. Thank you very much." I said.
Just as the deliveryman left, my phone rang, and it was Father Clarke.
"You should get a delivery very soon. It comes from my boss." He said.
"Who is that, God?" I asked in a puzzled tone.
"NO! Father Alfredo in Rome has sent it! He is sending you his church amplifier to get sorted, and I've told him you're our miracle worker." He bellowed down the phone in his usual Brian Blessed voice. I am sure he is partially deaf but I do not have the nerve to ask him, as he can talk twice as long and louder if he is upset.
"Thanks!" I said. I did not know whether to laugh or cry. I suppose no good deed goes unpunished.
The next day I opened the crate and this amplifier was in it together with a note, which simply mentioned that it was overheating.
Amplifiers generally overheat if the biasing is incorrect. The bias voltage is the DC output from the amplifier when there is no signal at the input. Ideally, it should be zero, but in practice, there is a small residual voltage. This voltage, called the zero offset bias, requires calibration through the provided pre-sets.
All you have to do is connect a meter to the output test point and turn the pre-set with a screwdriver around five degrees or so until the meter shows zero volts. It is so simple. They did not have to send it all the way to me; however, now that it is here I had better do a good job.
TOA is undeniably one of the best companies that manufacture some of the world’s finest amplifiers. If you are a singer or someone in the music industry, you will almost certainly have seen these boxes stacked on top of each other during a live “gig”.
These amplifiers are very reliable and can take a lot of punishment. Rock singers kick them around on the stage, yet they continue to operate with no loss in performance. These boxes have ventilation grilles at the top and base, so if they are stacked the airflow becomes restricted.
You often see the bass guitarist hanging his leather coat over it blocking the top grilles. If there is any kind of failure, it is always due to human error. On this one, the presets had moved, and all I had to do was to position them again.
This Article Continues...TOA Powered Mixer MX-106R
Look Inside TOA Amplifier
TOA Amplifier Passive Heat Sink
TOA Amp Power Resistors
TOA Amp Transformer & PSU