Kenwood KA 405 popping...

[guyakaguy]

Hi everyone! I'm new to the forum, but I've been a long time lurker.

I have a late 70s Kenwood KA 405 receiver that I've had for about 5 years. I got it from a friend who was going to throw it away because the input and monitor switches were REALLY scratchy and causing the sound to cut in and out.

I got some deoxit and cleaned all the switches and pots, and found a set of really nice mint Kenwood JL 850 speakers for next to nothing (A side) and a couple heavy 4" speakers I already had (B side), put some LEDs in the burnt bulbs,and it's been working and sounding like a million dollars since....

Except that now over the last few weeks it's been popping or snapping intermittently over both channels. I've put it on only the A channel, only the B channel, only the left, only the right, loudness on and off, power amp set to "direct" and "tone on" and it pops no matter what I do. The sound doesn't cut out, at least not noticeably, and the power meters jump when it pops on both channels.

Am I about to blow a cap or is my amp going out or what?

 

[WaynePflughaupt]

Congrats on scoring a nice vintage piece! However, most likely it’s going out. You possibly didn’t do it any favors by running both pairs of speakers all the time.

Regards,
Wayne A. Pflughaupt

 

[guyakaguy]

I'm guessing just run it until it starts to smoke and get a new one?

Then start the de-soldering process, or is it not worth ripping apart.

 

[fmw]

You have already blown one or more caps. Very common in units as old as yours. Time to replace the Kenwood with something newer.

 

[Latent]

You could have fun de soldering and replacing every single capacitor in the unit so that it may last another 40 years but there is a big risk that it either won't help or you will make it worse. May not be easy to read the specs of all the caps to find what to replace it with either.

 

[guyakaguy]

It could be invaluable as a learning experience if nothing else (after getting a new receiver).

Anyway, any recommendations for a newer lower end receiver with decent turntable ability?

 

[TLS Guy]

It could be invaluable as a learning experience if nothing else (after getting a new receiver).

Anyway, any recommendations for a newer lower end receiver with decent turntable ability?

Start by replacing the smoothing caps in the power supply. That has a very high chance of curing the problem. If you replace every cap, you will make a mistake and do more harm than good.

 

[guyakaguy]

Sorry, the speakers are JL 640s (120w vs the 850s 180w).

So, any old (new) receiver would be good?

The same friend has a 200w Insignia receiver and has been content with it. I suppose at this point, and even when the Kenwood worked perfectly, a new receiver would blow it out of the water.

 

[guyakaguy]

Except apparently the Insignia receiver doesn't have a phono input, which means no pre-amp, which means no Insignia.

Maybe I'll have to find another vintage?