Help troubleshooting a purchased chip amp

[Mark2727]

Hi,

I am new to this forum. Hello everyone!

I am not an expert in this hobby, so I decided to purchase a chip amp from a vendor on eBay. Actually I got two.

Problem is, they are very hissy sounding. Not hum, hiss.

I wrote them (this is ongoing) and they said with "two capacitors" this can be resolved.

Does this sound plausible? Or are they just blowing me smoke?

I can point someone to the schematic, etc. if they are willing to help me.

I just want to make sure I do this right. I don't want to have to bear the cost of returning these to China/Taiwan.

Thanks,
Mark

[woody]

You might tell us about the power supply especialy what size
and make caps are used. If they used realy crudy filter caps
that could be the problem or it was in an old Advent 300 receiver
I had. In my case a bypassing the caps solved my problem.

[AndrewT]

post the schematic and a pic or two of the amp.

[Mark2727]

Hi,

I am trying to obtain a schematic.

The amp is a "HLLY" brand, model "Tamp -90". It uses a chip numbered 2024.

Here is an eBay item number. If you punch it in the search bar on eBay and scroll down you can see detailed photos of the inside.

Item number 330316621345

I am just a beginniner, but appears the power caps are Nichicron 4,700mF ones.

Thanks,
Mark

[nic6paul]

I would try the class d section. That chip is a tripath 2024

[ttan98]

TA2024 a Tripath amp(not chipamp) is inherently noisy(I have one), esp. when you connect it to an efficient speakers.

[AndrewT]

Originally posted by Mark2727
...I am just a beginniner, but appears the power caps are Nichicron 4,700mF ones.

mF is wrongly used in this context. Many US manufacturers use m to indicate micro (10^-6), where u (Greek mu) should be used.
You have 4700uF smoothing capacitors. 4700mF would be 1000 times more volume.

[Mark2727]

Hi again fellows,

OK, thank you. I will post over at the class D section of this forum.

To update, the manufacturer did send me some instructions with photos and suggested capacitor additions to the board.

However (at least to me, a beginner) these are not totally understandable as to exact placement. I'm sure one of you guys with more experience would be able to guide me.

Another thing they didn't tell me was which voltage these several caps should be, even though I specifically asked them.

I just hope, given one of your comments that these can indeed be quieted down. Someone mentioned this particular chip is "inherently noisy with efficient speakers". I have Klipsch LaScalas which are about the top of the heap in efficiency.

Thanks everyone! If you can help me on an individual basis and would like to see what HLLY company sent me, write me directly.

Regards,
Mark Williams