General HIFI > Amplification (Pre/Power)

one woofer pump_ground issue?

(1/9) > >>

data:
Hay guys

I'm at a lose on this one  :(

With the EAR Clone I have a touch of hum, slightly more in the right.

But the issue I'm trying to sort out (might be one and the same) is that when adjusting the volume pot on my main amp, the right speaker woofer pumps (left does not). There is a whooshing sound with it, move the volume up and pushes the cone outwards and move it down and it sucks it inwards. This only happens with the movement of the volume pot.

I think It's a grounding issue of the Clone as a CD played is OK, but wondering if the above symptom can narrow it down in any way?

The IEC earth goes to the ground post for the tables lead on the inside of the case, and this is the chassis ground point. I have tried it with the circuit ground (from PCB) tied directly from the RCA grounds to this point with and without a cap, and floating also, doesn't make any difference. table ground wire connected and not, still no difference.

Any ideas?

Thanks
Ian

klackto:
Sounds like there may be DC on the output of the pre. One of the coupling caps may be leaky.

data:
That would be a VSF cap :(

I'll swap them over and see what happens.

Cheers

Tuyen:
Does sound like a leaky output cap.

Fingers crossed it isn't a vsf.  In saying that, I've had two vsfs fail in the past. So I wouldn't be surprised.

Let us know how you go :)

stevenvalve:

--- Quote from: Tuyen on October 07, 2014, 01:40:03 PM ---Does sound like a leaky output cap.

Fingers crossed it isn't a vsf.  In saying that, I've had two vsfs fail in the past. So I wouldn't be surprised.

Let us know how you go :)

--- End quote ---
I to have had some fail, an expensive problem

Navigation

[0] Message Index

[#] Next page