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

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.

I wish I could change my moniker...

Perfectionist: A few issues to answer your question as to why I tried this other tube ring instead of the Herbie. The Io and Callisto each with one PS totals a whopping 40 tubes. Looking at the cost of the Herbie rings, that's a lot of pizzas. These other rings are very inexpensive to try before going to the next "level".

Another issue is that the Io has 4 pairs of 12ax7 tubes that are only about 1/8" apart. The Herbie rings here would just not fit. And the set of 6 12ax7's in the PS's are placed just as close. These other rings just barely fit if I strategically position the rings on these adjacent tubes. All other tubes in the Io and Callisto would handle the Herbie rings with no problem.

If I had 4 or 6 or so tubes total, I would be very willing to put forth the effort to try all sorts of positions of the rings on the tubes. But with this many tubes, it would be insane. I'm still recovering from all the cable auditioning over the last 2-3 months!

I simply put a pair of rings on the tubes last night that were the most microphonic. This is easily determined by lightly tapping each tube with a pencil....and let the ringing begin. Even with a couple tubes, there was some ringing in the system while adjusting the Callisto's volume pots. But with these rings placed last night, that is now entirely gone. This was great news alone.

With the Dominus cables now in my system, I have so much more low-end extension and dynamics that when the volume has become quite loud, I can hear some of the tubes start to ring.....specifically in the Io. This made be partly due to the Io's cover being off but also surely because I have very poor isolation under these components. Hopefully tonight I can crank up the volume and determine if these rings have alleviated (or at least greatly reduced) this issue.

John

John, I don't think tapping on tubes is such a good idea. It's very unlikely that this is a proper way of finding the most microphonic tubes. You can probably end up damaging the tubes like that. Here is a pretty cool article about NOS tubes that I enjoyed reading - http://www.soundstage.com/tubeor/tube.htm