DI box distorting signal - is it faulty or am I?

[linear]

Ok, first newbie question:

I received a shiny new DI box for Christmans, a [url="http://www.samsontech.com/samson/products/processors/s-class-mini/sdirectplus/"]Samson S-direct Plus[/url]. I only got around to testing it a few days ago and I'm getting distortion from it.

If I turn the volume knob on my bass down past half way the signal cleans up and it sounds ok. I thought it was maybe because my bass had an especially hot output (Yammy BB414, passive), but I tried it with my old Westfield P, and the same thing happens. This is going straight from bass - DI box - recording interface - headphones. The level guage on the interface is in the green, and I can turn the preamp gain right down and still hear the distortion. As it's a stereo DI box, I've tried both channels, and it's the same thing. Tried a different instrument cable, no change. I've got the Level switch on the DI box set to Guitar (I think, the switch isn't labelled well) and it was running on phantom power.

Is this overloading of a DI box a thing that happens? Am I doing something wrong?

[linear]

Answering my own question

I did a bit more searching around online, and it seems that in some cases an active DI box may actually have more headroom when running on a battery rather than phantom power. Popped a battery in, and it works!

Still not 100% sure whether to send it back or not. I'm guessing a better quality box wouldn't have this problem, but I can't afford that. Could it be that the phantom power delivered from my budget recording interface is just a bit lacking in power compared to the norm? I really wish I'd asked Santa for a passive box :*(

[DolganoFF]

Some lower-priced interfaces don't provide full 48V of fantom power (it can be as low as 18V at times). Usually not a problem with modern condenser mikes, but could be with older mikes and DI boxes, indeed.

You'd have better luck with passive box...

Edited March 6, 2014 by DolganoFF

[Jack]

Yeah my tired old mixer at home can't give my countryman enough phantom power to give it huge headroom. It works flawlessly with our proper full band pa mixer though.

My point is that a 'better quality box' may not actually solve your problem. A cheaper alternative to a new interface or a new di box is a [url="http://www.thomann.de/gb/millenium_pp2b.htm"]phantom power supply[/url], but an even cheaper solution than that is to just use a battery.

[linear]

Thanks guys. I'm going to take it down to the practice rooms some time and see how it does on the phantom power from the PA - I'm assuming it will be just fine. Just running it off battery would suit me fine too though, as it's not somethhing I'll be using that often.

Still kind of wish I'd got a passive box though. I rather naively assumed that active=better, but, after a bit more research, I see it's not like that at all.

[DolganoFF]

Yeah, passive boxes work well enough with much less things to go wrong. I occasionnaly work as live sound engineer (you know, one of those sound guys every musician hates ). I only use passive DIs, don't see any reason to bother with en active...

[Jack]

I sometimes find that a low-output or passive (or both) bass can sound weak and distant with a passive DI. The same is certainly true for guitars. You're right though, in most circumstances a passive would be fine. Certainly, seeing as mine sits on a pedal board being fed a buffered, hot, signal, maybe I should have gone passive............