K8060 buzzing humming

Kits Audio Hi Fi Projects
1

I just finisht my k8060 and adjustid the bais.

Right on the first time when i connected completly There was a A very great Buzz trough the speaker.
I read it could be a cable problem between the input cables and the the AC cables so i adjust it.

Problemen stays.

I have solderd the input cables off and put the AC on again There was only a A very lite humm what i have heart often so no problemen with it.

When i hold a (isolate)cable near the input pin the Buzz starts getting bigger and when i touch te input pin the great Buzz is completly back.

The cable is not connected to something and is far away from de AC and DC.

What could this be?

The Buzz also starts when i come near C9 and it is 10uF

2

Does the input cable have a shield?

3

First it was a standaard speaker cable.
Later i tested it with a 220v soft cable.

4

The inputs should have a shield.

Remember this is an amp.
If it receives noise on the input it’s going to amplifier it.

5

How do i do that? The best way?

Not that i try it a couple of times andere brake the stuff.

Can i connect the earth line from the AC to the ground on the PCB?

6

Problem solved (i think).

First i did the AC earth line on de ground output.
Second i did the AC earth on the ground input because when i touch the pot it cracks allot.

Did test it on a cheap speaker with leds and with my phone it sounds OK the volume is a bit low, i think because of the phone/speaker combination. In my car the phone sounds al lot harder over the Pioneer radio.

When i have a box for it, it goes on the vsx920 and the k8060 needs to drive a 4ohm peerless xxls 12" subwoofer.

I already have tested a 2.2 wima cap between the input + and ground. Bass is allot more. (Read it somewhere on the forum)

Someone of you have more tips for it?

I put a k4307 extra in the box for fun. And the k4307 is alrready working on my center speaker
I hope tot have it finisht soon

7

And one more thing i discovered.

When i put the multiemeter on the output it reads about -17 the 17 is the lite hum, but the - i dont understand. Or is this normale.

Even when i play musical it still reads in de -

Multimeter stand on lowest DC stand (200m)

8

Try shorting the audio input on the K8060 PCB.
If the hum is gone, it is most likely due to a wiring problem (hum loop) or poor shielding of the wiring (or both).

9

I connectid it all and the sub sounds great! (With he the 2.2uf cap)

Stille nog finisht hut it is up AMD running