BR800 Questions: Frame Rate and Hissing/Interference

[Wilbury]

Hi everyone!

A couple of questions about BR800. I mainly use it as an interface to work in Garageband. Generally, it works ok, but there are two issues that are of concern.

First, as I turn BR800 on while in Garageband, the program detects the device and says that it sends signals at a non-standard frame rate, i.e. 29,97 rather than 25 or 30. I then choose to accept 29,97 and all works. But still I wonder why this unusual fps value. Any ideas on this?

Second, BR800 makes a slight yet unpleasant noise, like a small mosquito, that I can hear both through the Garageband/Mac sound output and though BR800's own audio outs. Experimentally I've found that this noise is produced when my Mac is on (it's not the Wi-Fi module; most likely — the spinning HDD) and is carried to BR800 via the USB cable. So it is a matter of some interference. I wonder if all or most budget audio interfaces are prone to this or if some other ones, particularly those having a metal case (unlike the plastic BR800), are free from this problem. Please let me know if you have any experience on this subject.

Any info will be much appreciated. Cheers!

[AndyR]

Hi, can't help on the frame rate thing...

But the hissing interference - not familiar with Macs, but I'm assuming this is a "laptop with a power supply" type thing? If it is - have you tried disconnecting the Mac's power supply and letting it run off its battery while you're tracking?

When I was using a laptop to record in a DAW years ago, connecting anything else to the laptop that was running off the mains caused whines/interference noises that were picked up by the audio interface (in my case it was the powered studio monitors - switch them off and all was fine... but then I was stuck with headphones). If I used a mains powered desktop PC instead of the laptop, no issues at all.

I scratched my head for ages, and then one day someone said to me "it's your laptop's power supply - run on the batteries when you need the noise gone" ... and that removed the problem.

[Wilbury]

Thanks AndyR!

In fact, I'm using a Mac Mini. It has a built in power supply. So the battery option is not available in my case.

I experimented quite a while to establish the source of the hissing and eventually came to the conclusion that Mac Mini adds something to the signal that is fed back to BR800 via the USB cable.

Luckily, the noise is only present in BR800's own audio outs. So I solved the problem simply by connecting the monitors to Mac Mini's audio out.

Having said that, I think that it is a good idea to switch off all irrelevant mains-powered equipment while making a recording. For example, I noticed that a Philips energy-saving lamp adds some hiss to my radio. In fact, it was the last thing to suspect. But you never know... ))

Hi, can't help on the frame rate thing...

But the hissing interference - not familiar with Macs, but I'm assuming this is a "laptop with a power supply" type thing? If it is - have you tried disconnecting the Mac's power supply and letting it run off its battery while you're tracking?

When I was using a laptop to record in a DAW years ago, connecting anything else to the laptop that was running off the mains caused whines/interference noises that were picked up by the audio interface (in my case it was the powered studio monitors - switch them off and all was fine... but then I was stuck with headphones). If I used a mains powered desktop PC instead of the laptop, no issues at all.

I scratched my head for ages, and then one day someone said to me "it's your laptop's power supply - run on the batteries when you need the noise gone" ... and that removed the problem.