[Ricky Monk]

I just picked up an OBH-11SE & the regulated North-American supply.

Now, don't groan, but my only source for the moment is my laptop (Which didn't quite have enough juice to drive my Senn HD570s all the time).

The creek is hooked up through the line out.. though I get the same results through headphone out it seems.

I can now hear interference that wasn't there before. I don't expect it's simply because the amp is more revealing.. things sounded fine before, without the interference. Seems to be mostly video.. as it depends on what's on screen at the time. Also drive related noise.

I also notice if I touch the amp casing, the background hiss rises.

What I'm wondering is if this is perhaps some sort of grounding issue, or what else it could be. I know the laptop is far from a perfect source... but it seems to me I should be able to do something to reduce this.

Any ideas?

 

[TravelLite]

Ricky Monk, a good first step would be to try the Creek from another source, e.g., a PCDP or perhaps a FM radio. If you don't have anything at hand, maybe you could borrow a friend's unit.

TravelLite

 

[Ricky Monk]

I can do this yes.. I'll run it through my dvd player.. but what am I trying to prove? I'm 100% certain the noise is coming from the computer.. as would normally be expected.. what I wonder is if it can be reduced.

I'm starting to suspect it's level related.. I can't really hear it until I get the volume at a level that was higher than what the builtin headphone jack could produce with these cans...

Cheers.
Rick.

 

[TravelLite]

Quote:

Originally posted by Ricky Monk ...what am I trying to prove?

Ricky Monk, the idea would be to rule out any problems with the amp, since it's the new variable.

Of course, also try your laptop on AC power without a battery installed, as well as on battery power while disconnected from the mains.

Unfortunately, ground loop problems are not all that uncommon with some laptops.

A classic work-around is to lift the ground or raise the earth with an inexpensive three-prong to two-prong AC adapter plug, AKA a "cheater" plug. However, the very mention of this is enough to send some folks into a hysterical fit!

Actually, for more useful info, you should probably post in a user forum specific to your laptop. For example, Dell has a DellTalk audio conference if you happen to have an Inspiron or Lattitude laptop.

TravelLite

 

[tangent]

Forget all those tweak ideas for your existing analog audio, Ricky. What you need is a USB DAC, to get the D-to-A conversion outside the RF bath inside your laptop.

If you're wanting the most compact setup, there's a tiny little thing from Xitel that takes USB in one side and puts analog out on the other. There's no amplification, so it requires no external power.

If you can deal with some extra bulk, get the stereo-link, which I reviewed here at Head-Fi many moons ago. It's about the size of a hardback book and it requires external power. (Not a wall-wart, thankfully -- the power supply is internal.) The tradeoff is that it includes a passable headphone amp and it has RCA outs which you could send direct to your Creek. You'll want to hook your Creek up for best results, since the internal amp isn't as good as even a CMoy amp.

One other option is a PC Card audio adapter. There's one that was reviewed in PC Magazine recently by Bill Machrone that is made by a small music equipment company. It works like a USB DAC -- the D-to-A is done outside the PC, in a separate box that hooks to the PC Card.