Herbie's Hal-O tube dampener's on Calypso?

You Calypso folks are quite the helpful friendly bunch.

Last week I ordered up a bunch of these. I will report my findings in the Io and Callisto as I have to believe the improvements (if any) should be similar.

Steve is a great guy.You have nothing to lose with a 90 day return policy.

JD, that's promising info as a buddie of mine just told me he always felt they made the sound more closed in. But, I wanted to try them for myself. Should I just slap on all four, or do either the gain or output stage first? Any recommendation on that? Or positioning the dampner on the tube? Supposedly, even that can make a difference.

Jafox, why you no go with Herbie's?

I have used Herbies Halos for quite some time. On EL-34s, 6SN7s, and multiple types of mini pins. In every instance there was an improvement in sound, but that is not to say some experimentation was not involved. Steve counseled me that the use of the Halos are not an exact science. You will get different results depending on how they are used. On my preamp, I started with the gain stage, then the buffer stage (Cary SLP-98). First on the middle of the tube, then moving it up gradually. I finally settled on just below the top mica. As for the amp, same method, but they seemed to work best above the top mica on the EL-34s. Now on my Joule Electra preamp and Hagerman Trumpet phono stage, they are used in the middle of the tube, as closer to the top seemed to take some of the naturalness out of the sound. I learned a lot depends on how well the designer has dampened the area where the tube sockets are mounted, as well as how microphonic the tube is to begin with.

Mr. man of no mistakes; I think the feeling of closed in may be an illusion created through a rounder more human image to the edge of instruments and voices on the soundstage. With the dampers there is a slight lessening of the "cut out" appearance of the soundstage. I simply put on all four at once, and spent no time trying to decide if one set of tubes was better than the other. I did try moving them on the tube and per the instructions you will receive, I found them best at the top 1/3 and actually just below the silver cap line.