Tag Archives: Firestone

Firestone Audio GreenKey USB Isolator and FR-H001 Headphone Stand Review

First of all I would like to thank Firestone Audio for sending me these products to review.

I shall start off with the GreenKey USB isolator.
First of all, purchase information
GreenKey USB Isolator – $102 / £50 / €59 – Available from:
Amazon USA

Here are the pictures:

The USB isolator is a product I wasn’t expecting to change a great amount of audible sound, especially in a setup at my desk, which consists of my modded Denon AH-D2000, the DigiZoid ZO2 and an EHP-O2D. I was trying so hard, for such a long time to hear a difference, whilst using the EHP-O2D in DAC mode. No matter what I did, I couldn’t hear any difference whatsoever in sound. I tried different USB ports, both at the front and back of the PC and 2.0 and even 3.0 ports. I was just about to give up and say: “this product makes no difference”, until I turned on my DigiZoid ZO2 and decided to hook it up to the PC and charge it at the same time, whilst it was in operation. This is where I discovered a difference in sound with and without the GreenKey.

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Firestone Audio FireyeHD Amplifier Review – A good contender

First of all I would like to thank Firestone-Audio for sending me the amp for review.

The FireyeHD Headphone Amp costs: $130.00 / £170 / €200 and is available from:
Amazon USA

Written review:
As I live in the UK – the review will be based on the product costing £170.

Packaging & accessories:
The FireyeHD headphone amp is a beautiful piece of kit, that comes in a nice little package which is quite simplistic. The amp includes a USB cable to charge the amp, a 3.5mm to 3.5mm interconnect to connect it to your given source and a charging wall brick.
I should say, that despite me living in the UK, Firestone Audio sent me a EU plug – thus I wasn’t able to use the wall charger at all. I don’t know if they provide a UK wall charger, but I would presume they would do so. Other than that, the amp came with what I would have expected from an amplifier package. It would have been nice to have had a little carrying pouch included for the FireyeHD as it is designed to be a portable amp.

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