East End Hi-Fi are authorized dealers for Computer Audio Design’s Ground Control Products (GC1 & GC3) and we have the GC1 available for audition.
Here’s what Michael Fremer of Analog Corner had to say about the CAD GC3:
“Now that I’ve lived with the CAD [Ground Controls] for another couple of months, I can render my verdict : I can’t live without it. After listening for weeks, I pulled it out of my system, listened for a few minutes, put it all back immediately, then wrote a check”
Unfortunately there isn’t a common industry accepted technique for measuring noise levels on Signal Ground or Earth. A common measurement is Signal to Noise (S/N) ratio. S/N is the maximum output of a device (0dB) divided by the minimum output of a device (the noise). The reference for both of these measurements is Signal Ground. S/N measurement is not the whole story because it does not tell you anything about noise on the Signal Ground. You can have a very good S/N measurement and in reality the system can have considerable noise on the Ground side.
The CAD GC1, GC3 & GC-R Ground Controls can be connected to any audio product that has an unused output or input connection. If your DAC, streamer, computer, phone stage, preamplifier, amplifier, CD Player, NAS, etc. has a spare output/input connector like an RCA, XLR, Spade, USB or BNC you can connect the Ground Control to that. We supply a range of interconnects with various connectors. The other end of the connector has a single 4mm banana plug that attaches to the Ground Control.
We typically get the best results connecting the GC1 Ground Control to the device in your system that has the highest noise levels: components like computers, audio servers, DACs, CD players, NAS, routers etc. or by connecting the GC1 Ground Control to mains Earth. These are the best places to first try connecting the GC1 to. The GC3 & GC-R work exceptionally well connected to your mains Earth connection and directly to the cases of your amplification.
We also have had very good results connecting a Ground Control to phono preamplifiers. The gain on these devices is large and the reduction of noise that the Ground Control provides has brought some amazing results.