Do tube dampers improve sound?

I've done well with Herbies Halos as well. However, it is important to note that the use of Herbies Halos is not an exact science. While there is a recommended position for them, you can and should experiment with placing the Halos at different positions on the tube to see what works best for you. I have used the rings mentioned in the other thread and while I feel they are a worthwhile choice, the Halos were better for me.

Using the Halo's is more like an art than an exact science. There is no real formula or equation for success. You have to play round with them and see what, is any position, works best. They may only provide minute improvement or could make a huge difference based on a number of factors.

I was told by Brendan at Tube World to think of a tube like a car antenna. Closer to the base the less flexible it is. However, closer to the top is where it is most likely to sway. That is why a lot of these tube tweaks seem to work best at the top of the tube. I use my Halo's about a third of the way down from the top. Best results have been with my phonostage. They did not affect my tube preamp as much.