Integrated amp question

Perhaps the amps power is the same but your hearing is not as good

A common problem with amplifiers this old is the electrolytic filter capacitors in the power supply dry out and lose their effectiveness. You might try replacing them.

Stevem hearing ok eyesight is corrected with glasses for reading if I can find them.

Where do you find/buy electrolytic filter capaciters? Or do you replace the entire power supply ? I am more mechanical than electric versed is this something I can do ?

Roadapple,

Both Digi-Key and Newark have a huge selection of electrolytic caps. Be very careful to get the same capacitance (in microfarads) as the part you are replacing, because that is what the circuit is designed for and the same (or higher) voltage rating (VDC) because otherwise they will explode . You may want to get an electrically inclined friend to help you with this. Cheers.

Wrong place for suggestions. That amp is better than thirty years old and no doubt a tube amplifier. I never heard of a Nikko amp and you don't tell us the wattage.

All amps these days are "integrated" if by integration you simply plug in the indicated device, turntable, tape deck, etc., in the indicated input.

You should be able to get a nice hundred watt stereo tuner and amp in one unit for anywhere from a hundred dollars on up.

I say wrong place for suggestions because you get suggestions like replacing electrolytics just on a hunch that in old stuff they go bad, not to mention you don't even claim to be an amateur electronic tech. If the amp is still operating but seems to have lost power it is more likely a tube gone gassy. After all, in a thirty year old amp, the tube getter may have gotten all the gas it can get.

If those electrolytics have gone bad, they filter the D.C. from the rectifier, open circuit you would get heavy 60 cycle hum; if shorted they would take out the supply so you would have a dead amp.

Go buy a new amp and you will appreciate all the more this advice for the cleaner sound you get from solid state gear. No hum, no hiss, no tube noise although I will admit some crazy musicians think tube noise in their amps is the cats whiskers.

j.

Jack Jersawitz the model for the amp is NA-850 60 watt amp. As far as CR4 being wrong place for suggestions I received two good suggestions from yourself and and SteveM. I am considering repairing or replacing this amp. I like this amp and wondered if this is worth fixing. I was able to have my speakers re-foamed recently and these perform like new. We have a "Crazy musician" in our house who prefers a tube amp for his guitar. Due to his music tastes I cannot say I can appreciate this "sound" quality.

Maybe you could take off the back and pour in some replacement watts...

If your amplifier is a tube type, keep it and enjoy it. The tube audio amplifiers I am familiar with are the class "A" type. This means sinusoid in and amplified sinusoid out. Every other class of amplifier will introduce some sort of irregularity into the sinusoid at the output of each stage. There is not a very good chance you will find a solid state (transistor) class A amp for any price that is inexpensive. I have a class "A" transistor amp and it set me back quite a bit. The thing almost needs its own air conditioner too. There are plenty of reasonable quality class AB, B, or other that will provide sound reinforcement. However the sound quality is just not as good. If the amp seems to be at reduced power, get new tubes. I also do not understand the comment about integrated amps no longer available, and the need for a preamp. The integrated amp contains both a pre and main amplifier, among other things. The reason why I say keep the tube amp is look at the prices for those things on ebay. It is every audiophiles desire to hear music the way the band played it. In the case of studio recordings, the way it was mixed then mastered. The tube amplifier is the way to go if you can, no question about it.

Bill

The first thing I would do is to replace the tubes (valves in Europe). This may take a bit of hunting for a vendor who handles tubes these days. If you are lucky, you might find a local vendor who might also have a tube tester. This would allow you to test them individually and only replace those which are weak. Otherwise, I would just shotgun it and replace all the tubes. You might check with TV repair shops.

It would be a big help if we knew where you are located. My advice might be good for US, but if you are located in Australia or India (for example) other associates on CR4 could help you much better than I.

Sincerely

another Bill

This reply comes a bit late as I have been on holiday. All the Nikko amps of the late 70's I have seen were solid state so valves/tubes are not likely to be an issue. Most Japaneses manufacturers of mass market hi-fi of this era used integrated circuit amplifiers, most of which are unobtainable today.

As others have said, it is almost certainly the electrolytic capacitors which have deteriorated. If the main power supply electrolytics have degraded, the maximum supply current will be reduced which will reduce your maximum output power. Modern electrolytics will be less than half the size of the originals. I would resist the temptation to increase the value of the capacitance as this will increase the switch on surge current.

Modern integrated amplifiers are available although few have RIAA pre-amps for turntables. I still use quite a few similar hi-fi amps from this era for workhorse applications such as office and meeting room amplifiers and there is every chance that with new capacitors your amp will last for a long time yet. However if your switches and pots are becoming intermittent I would replace the amp as they more difficult to replace than the capacitors.