Kojo Technology virtual grounding plugs: Do they work on a preamp?

The Kojo Technology Crystal Ep plug is fixed to an unused RCA jack beside the pre-out connectors of the Burson Conductor 3X GT DAC/headphone amp/preamp.

By Lam Seng Fatt

After the Kojo Technology Crystal Ep virtual grounding plugs improved the sound when fixed to the black terminals of my ATC speakers, I tried the third plug with RCA cap on my preamp. I couldn’t find any unused RCA input in my streamer/transport, DAC or power amp, so I had to use the tube Lamm LL2 Deluxe preamp for the test.

From what I have read about these tweaks, they are very system dependent and they may work with one component but not with another. In a review I read about Nordost’s QKore grounding system, the reviewer noted that he heard different results when he plugged it into an RCA input compared with an XLR input, and different components fared better on different inputs.

On the tube Lamm preamp, the Kojo made the sound smooth but took away the ‘energy’ and ‘life’ from the music. I was playing a Diana Krall song which was already smooth and the Kojo plug made it even smoother with diminished dynamics.

I have with me a Burson Conductor 3X GT DAC/headphone amp/preamp for review. This is a balanced solid-state design.

So I linked it to the Bryston 4B SST power amp and started listening to music using XLR cables. Then I plugged the Kojo Technology virtual ground into the black and then the red RCA ‘pre-out’ jacks (since I was using a pair of Audience XLR cables) and finally into an empty RCA jack next to the pre-out section. All three positions produced similar results — the sound became smooth.

But there was a difference. Again I played a Diana Krall ballad and on the Burson solid-state preamp, the sound was quite smooth but there was still a hint of dynamics and ‘life’. It was not as bad as on the tube preamp. On the Burson, the sound quality rendered with the Kojo plug in was actually quite enjoyable.

However, when I played a grunge rock number — Nirvana’s Smells Like Teen Spirit — it sounded smooth but constrained with the Kojo plug in. When I removed the plug, the song regained its ‘freedom’ and ‘life’.

So the Kojo Technology Crystal Ep virtual grounding plug, just like its competitors, is system dependent — and also song dependent. It seems to work better on solid-state components than on tube equipment and it is good for ballads but not so good for rock songs.

My recommendation would be to try before you buy. And try plugging it into different unused RCA jacks, and listen to different types of songs before making your decision.

As for using the plugs to ground speakers (see https://www.av2day.com/2022/11/kojo-technology-virtual-grounding-plugs-do-they-work-on-speakers/?fbclid=IwAR3GnNngstII771SBVchT_VKVJoS0DYbWo819fsOHV5WEKv8ilqopZL_4hU) I would say: Go for it!

The plugs come in four types — RCA plugs, banana plugs, 3.5 mm mini plugs and spades. They cost RM800 each and are available from Begins Acoustic. Contact Kenix Chua at 012-6500610 for more details.

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