Tag Archives: mixer

Everything Else, Review

Osee Gostream Duet Vision mixer and streaming box.

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I’m sure many of my readers will be familiar with the Blackmagic Design Atem Mini’s. But how many of you have looked into the alternatives? I’m in the process of putting together a mobile production unit that can be used in my camper van or transported in a few small flight cases. I was going to use one of the Atem Mini’s but they only have a single HDMI output and this means you can’t have both a multiview output and a program output for a high quality feed, perhaps for a screen or projection at the same time as the multiview. So, that led me to have a look at some of the alternatives and the one I finally settled on is the Osee Gostream Duet.

Osee Gostream Duet switcher and streaming device.



No one asked me to do this review and I purchased the device based on the manufacturers spec sheet from Amazon, just as anyone else would. This review exists simply because I actually really like the product.
The Osee Gostream Duet is a 4/5 channel vision mixer designed for live streaming. It supports 4 HDMI and 4 SDI inputs plus a further external source which can be a UVC camera via USB-C or an NDI camera over the connected network. You have to choose between SDI or HDMI on each individual input, you don’t get 8 inputs at the same time, but you can have a mix of both SDI and HDMI sources. The very easy way the setup menu can be accessed from the Gostreams front panel means that you could quickly change the input settings during a session if you needed to have access to an extra source or 2.

You get a free NDI licence when you update the units software, so as well as the 4 main inputs you could have a camera connected over the network attached to the units ethernet port.  Or you can add another camera via UVC as the device can accept a UVC input via one of the 2 USB-C ports. In total you can have up to 5 external sources at any one time.

It has a built in video player able to playback H264 HD files from an SD card. If you use a suitably fast SD card such as a V60 or V90 card it can also record to the same SD card as used for playback. Or you can attach an SSD or thumb drive to one of the USB-C ports.  You can connect it to a Mac or PC where it will be seen as a webcam making streaming very simple or the device can stream to 3 separate destinations at the same time. There is a companion program for Mac or Windows to control the unit remotely and you can also control it via a Streamdeck or similar via the companion software.

It has an upstream keyer as well as a downstream keyer. There’s a DVE that can be used to resize and reposition the input sources and still frames. The DVE’s and keyers can be used to create a multi-source  “supersource” which can be instantly recalled as needed. You can chroma and luma key with ease and the setup for the keyers and DVE’s can be done without a computer as you can access the menu system from the units front panel.

All in all I’m really impressed by the Osee Gostream Duet, it doesn’t cost much more than an Aten Mini, yet offers a lot more flexibility. Please watch the video to learn more.  

Everything Else, Shooting Tips

Beware multiple power supplies!!

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From time to time someone will pop up on a forum or user group with tales of fried SDI boards, dead monitors or dead audio devices. Often the reason for the death of these units seems obscure. One day it all works fine, the next time the monitor is plugged in it stops working.

A common cause of these types of issue is the use of individual power supplies for each device. Most modern power supplies use a technology called “switch mode”. Most “wall wart” power supplies are switch mode. Computers use switch mode power supplies, they are probably the most common type of power supply in use today.

The problem with these power supplies is that the voltage they produce is not tied to a common earth or ground connection. A 12 volt power supply may have an output voltage that measures 12 volts across it’s positive and negative terminals, which is great. But the negative terminal might be many volts above “ground”. Used singly this is not normally a problem but if you use a couple of different power supplies with negative terminals floating at different voltages, if you connect them together current will flow from one to the other as the establish a common base voltage.

As an example if you have a monitor powered by one power supply and a camera powered by another, when you connect the monitor to the camera current may flow down the SDI or HDMI cable from one power supply to the other causing damage to the chips that process the SDI/HDMI signals.

Even if there is no damage this current can lead to audio hum or other electrical noise.

How can you prevent this?

First use only high quality power supplies. Wherever possible try to run everything off a single power supply. Powering the camera from a high capacity power supply and then feeding any connected accessories via D-Tap or Hirose outputs on the camera is good practice. Also powering everything by batteries helps. If you must use separate power supplies then connect everything together before connecting anything to the mains and before turning anything on. This should ensure that any current runs through the shield and ground paths in the cables rather than possibly travelling down the delicate signal part of a connection as you connect things together.