I recently purchased a Peak 4 made by Entreq. It screws on in place of the wooden lug holders on my Entreq Silver Tellus box. It is said to contain 5 different metals including Tungsten.
It does add clarity to the already great sound I have achieved. I can’t try it on my DIY version though due to the specific thread size.
But it makes me wonder if I should have included some Tungsten to my DIY box(es)
ozzy