help needed with nikko 230 distortion

I suppose that you've done the obvious, and swapped the speakers between channels ?

Arfa

Could be a bias problem, but if you aren't good with amps it would be pretty easy to blow up the thing and cause a much more expensive repair. That said, could be a bad bias transistor, flaky bias pot, open resistor, etc. Unless there were a common problem on this model which someone here just happens to know about (and Nikko's aren't the most common amps by a long shot) then real troubleshooting by a qualified technician is your best bet.

Mark Z.

Mark Z.

swapped the speakers, changed the source , and used different wires to make sure that it was in fact the amp the was the cause. the left speakers on both the a and b outputs have the same distortion.... kinda like gargling...... thanks for your time. me If you really want to talk to me - just eat the spam

the amp was free... so I am treating it as a learning experience rather than "I must get it working" . If I am unable to repair it then it will simply be tossed. thanks for the advise , I will look into that. me If you really want to talk to me - just eat the spam

ok just to update and close this tread: here is what I did to it. opened it up checked all fuses. ran some professional cleaner all through it tested it on some real speakers... still distorted. replaced light bulb for display.....IT WORKS!!!!!....Kidding. using some info I found from an Internet search I found the bias settings and test sites, so I started testing.... switched on and waited till it was warm tested working side and got a reasonable reading from it. tested the distorted side and got no (ie 0) reading from it. which indicated to me that there was no voltage going to that side. went back and retested the fuses with a multimeter and found one to be bad..... not blown just not working... popped in a set of new fuses to that grouping and restarted waited till warm, and retested the bias. very high.....so I adjusted the bias on both sides back to the recommended mv. and threw some music through it....... everything works super now. Am thinking of replacing the bias pots as they are a little touchy, and contemplating\fighting the urge to replace the caps as they are original and most likely dry.... but as they say if it works don't f**k with it. Recommendations on replacing?

thanks for the replies I received they sent me in the right direction. kallita If you really want to talk to me - just eat the spam

I'm a great believer in that old maxim "If it ain't broke, don't fix it". It has served me well throughout my long career in electronic service. It is a fact that electrolytics *do* fail, and the location / function of particular caps as a contributory factor to their failure, is well known. So by all means check them if you have an ESR meter, but I am absolutely against just changing every electro you can find, just because it *might* be faulty. In my experience, the 'shotgun' approach can easily result in giving yourself a bunch more grief than you originally had. With the best will in the world, no matter how careful you are, it is staggeringly easy to put a cap in backwards or get a solder whisker, and DC coupled amps are notoriously unforgiving of such errors ...

Arfa