I saw some recent chatter on a Behringer review of some amplifier ... so I fig'd I'd post this here...
I posted about this in some other topic - I can't believe that the Behringer UMC204 was considered "good" at all.
When I was looking for a down and dirty piece diagnostic gear for my main bench, I looked at Presonus, etc... Keeping in mind that this is typically use for repairs of stuff from places like the Birchmere here in DC, I really didn't give a poo as to the specs... as long as I could sweep with Daqarta or one of the other programs (a really nice free one is Spectrum Lab) and could connect it to my scopes I was happy... didn't really care about great specs.
So I get the UMC204 - you can see it on my bench.
First thing I noticed is it's not really balanced outputs. I even call the tech support guy - yep not really balanced out.
Well that sucks...
So then I figure I'll have to mod the patch bay with some transformers. Ok... I can deal with that.
BUT - what I couldn't deal with was the hideous HF noise I was seeing on my old Tek scopes and the newer Rigols. On my analog scopes I could see this fuzzy shit on a Lissajous... nasty...
So I ask the tech support guy about it. Turns out that for $70 they really can't do much as to filtering.
Just f'ing great.
So I open the f'ing thing up to see what I can do. Now I notice it's in a funky extruded AL enclosure. So I end up having to rip/machine away (too thick for an Xacto knive) the silly overlay at the locations for the hidden screws... (yes that's an old modem ... I still maintain a lot of old crap)
So I'm able to get rid of some of the noise - most of it. But there's still a shit load
On a sine wave:
Noise itself:
On the QA401 set to full span (stop 95kHz):
On my SA3032 Spectrum Analyzer set for Low Freq:
So needless to say I was surprised that Amirm's test were OK...
Thing drives me nutz... but for typical day-to-day silly I get sucked into (I'm no longer an audio bench tech - but still get asked to fix a lot of pro audio gear) ...