Amp's static noise and headphones.

2010-11-11 21:47:38

OK, here's my situation.

I recently bought a headphone amp named B-Tech BT928 and connected it to my onboard realtek HD-audio soundcard. I also own a cheap 2.1 system that I connected to the same port on the soundcard using a simple splitter.

This worked fine and all. No problems at all actually.

Still though, the speaker sound was crap so today I decided to invest in some better speakers as well.

I bought a package containing this amp and two dynavoice speakers.

When unpacking I realized that no speaker cables were included. Fine I thought, I test the new amp with my headphones.

So I disconnected the cheap 2.1 system and plugged in the new amp.

This is where it begins to go crazy. I only got sound on the right channel. Weird, I thought so I tested pugging in my cell phone instead. Everything worked. Puh, nothing wrong with the amp then.

It turns out that when the old system was not plugged in through the splitter the left channel didn't work.

This I blamed on the sound card (which I might add, I'm changing in a few days, I've ordered the asus xonar d1) and tried changing the main output jacket to another one.

That solved that problem. Now I got sound in both channels (yay! ), then I noticed the next weird thing. When I turned down the volume on the headphones with the slider attached to the headphone cable the sound begun to sound like when someone has played too loud on a speaker. This does not happen on my original headphone amp. My guess is that this is because I haven't attached the new speakers yet, could that be it (I'm buying the cables tomorrow)?

Also, the new amp provides a lot less bass to my headphones than the old one. Is this normal?

This is probably some basic things, but I'm kinda new into more advanced audio setups (anything except plugging in 3.5 mm plugs).

Thanks!

Edit: I just realized the topic title did not match the content of my post. When I changed the output jacket on the sound card I did not recieve static noise.

Amp's static noise and headphones.

Reply #1 – 2010-11-11 23:00:42

You've got some weird problems! 

A couple of possibilities come to mind...  These are just wild guesses....

1.  The amp might have "bridge" outputs.  In that case, the speaker outputs don't have a ground connection, and both terminals on each channel are "hot".  When you hook-up headphones, you've got only 3 wires to share between the 2-channels and something gets shorted-out.  (Bridged designs are very popular in car stereo amps because you can get more power from the 12V power supply.)

2.  The class-T design might need a load (4-8 ohms) to operate properly, and it may not work with headphones (typically 32 ohms or more).

Amp's static noise and headphones.

Reply #2 – 2010-11-11 23:20:38

Thanks for the input.

If it's (1) then hopefully it will be resolved tomorrow then I get the wires for the speakers.

(2) makes sense since the problem shows when the headphones recieves less power. I've ruled out the sound card on this issue as well since it appears with my cell phone as well.

Hopefully when I get the new sound card (should arrive next week) most problems will be solved. Because something is really messed up with the onboard realtek crap.

I'll update with info tomorrow after I get the cables and spoken to a friend who knows more than me on the subject.

Amp's static noise and headphones.

Reply #3 – 2010-11-12 18:12:14

Finally got everything set up (puh). The problem with the headphone's are still there, but that's it. I haven't noticed any other problems. And since I can still change volume with the amp's slider I think it'll do.

The new speakers are amazing. Or, rather amazing compared to my old ones 

When I get the new sound card (monday) and the speakers have been playing for a while I think it will be great!