20 Most Recent NAD C272 Amplifier Questions & Answers

Ref NAD C272 Power Amp how do I connect a ground Wire to this Amp this amp has only got a 230 Bolt 2 Prong Plug. There is no 3 Rd Earth Prong .and when my amp is on get high pitch Noise on my speakers. I need to ground this amp how do I do this. Please Confirm

My solution was actually indeed the output protection relay. What I did was to open up the relay and use contact cleaner and a very fine abrasive to clean the contact surfaces of the relay. After that, the problem was gone!

The way to diagnose this for me was to run the amplifier open until the problem recurred and to simply tap the relay's box. The sound came on immediately, and I was convinced.

Normaly this is what cause little volum and distortion. Check first if you got +68/-68V on amp module left and right Often the -68V is missing. This is caused by faulty transistor Q712 (2SA872) in +68/-68V power supply.

yes........you may have to replace the stk output amp ic or the discrete transistors for the channel affected.....good success, regards, Meder's tv service

This is caused by the breakdown of a transistor early in the amplication stages. If it can not be controlled at all by the volume control, that helps to narrow down the suspect transistor(s). This unit will require internal measurements with an oscilloscope to determine the exact source of hte noise. Unless you have access to this type of test equipment, this unit will need to see a servicer. I can try to locate the more probable parts, but I will need to know the exact model and serial number. There are differences in the circuitry depending upon the run/serial number.

Dan

Hi,

Your right, the remote will not switch the speakers.
There's no remote input on the power amp, so there's no possibility to switch between A and B speakers.

regards,
Gerard

This could be a bad solder joint, or dirt in the volume control. Try spraying the volume control with Servisol Video 40, available from electronic shops such as Maplin, or Radio Shack.

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You have a fault in the power amp. Identify the faulty channel by following the input leads. As, a stereo amp is basically two mono amps put together. You can compare the bad channel with the good one. First thing to do is a visual look around. If you see something odd looking in one channel and it's the faulty one, compared with the good channel, you might have found the cause. Look at the devices or device on the heatsink especially. If nothing stands out, the next thing to do is test the channels. You can do this in two ways. First, by touching the parts on each channel (with power on) with an insulated screwdriver. If you get a buzz in one channel and nothing in the bad one, in the same places of course! You might have located the faulty device. You can do the same with a volt meter. The readings should be the same in each channel. Work forward from the end of the preamp stage. Don't bother with the power supply parts, as they are common to both channels. By the way, don't short anything!

Distortion is categorized in Hum, Motorboating etc. Anyway see page 9 of owner manual for help. NAD C325BEE AMPLIFIER OWNER'S MANUAL ' ManualsLib For further help see page 24 of Service Manual NAD C 325BEE SERVICE MANUAL Pdf Download ' ManualsLib

I have nad t748 but not switching on the power on tha auto turn off

It is funny, I was just reading an article today about New Acoustic Dimension Cassette decks saying they were top of the line and equal to Nakamichi. The most likely reason is that the volume control needs cleaning with Electrical Switch Cleaner. You would have to remove the case and look. It is worth a quick spray. This says it has a motorized volume control. https://www.google.com/search?q=nad+1600+receiver+volume+on+high+volume ..

You can find volume and balance control components for the NAD 1300 preamp from a variety of sources. You can check with NAD directly, or look for parts on websites such as eBay or Amazon. Additionally, you may be able to find parts from audio/electronics shops in your local area.