Tube dampers/coolers effect on preamp sound?

My experience in my Jadis tubed preamps (using Tubesox, Top Hats, Vintage Tube Service's brass dampers (the best of the ones I tried) and Mapleshade dampers) has been that the better tube dampers take away a little bit of that tube warmth but give a bit more focus and clarity to the sound. This would be consistent with lowering the tube microphonics, getting rid of a small amount of distortion. Given the commparatively inexpensive choices available to you with the Herbies and Audio Research dampers, you might just want to experiment and see if you like the sound better with or without.

All tubes are at least a little microphonic; if you don't believe it, try a Herbies tube damper on a supposedly non-microphonic tube like a Military grade 6SN7 or 12AX7.

My experience is that tube dampers are essential. They can improve low level resolution, microdynamics, and allow higher volumes before distortion limits the volume at which you're comfortable. One thing I've found is that it's important to damp the tubes, but not to add mass that can store vibrational energy and then release it. Specifically, I recommend avoiding those tube damping rings that ARC supplies with their preamp tubes. Substituting Herbies Ultrasonic tube dampers on my ARC REF3 preamp eliminated a smearing quality compared with the ARC o-ring dampers. I mentioned this to ARC when I ordered tube replacements.

I do use very thin o-rings on the brass bases of my Kronzilla T1610 tubes. I find that four of these (1/16" thick and 3-1/2" diameter) made a surprising improvement in the sound, with instruments sounding more like solid and independent sources. Interestingly, when I tried putting those thin o-rings (rated to 450F) on the glass of the tubes, they start to smear the sound. For the glass envelopes, I use three Herbies tube dampers per tube.

There's lots of different types of dampers out there. I'd appreciate the input of those who have compared the Herbies dampers with other designs. One more thing, I've found that damping speaker cables also provides improvements.

Kernelbob, Herbie's makes dampers for IC connectors, but please explain to me how and why you damp speaker cables. I'm still not sold on the effectiveness of the IC dampers, but what are your findings with your speaker cables?

thanks... and I'm a faithful Herbie customer.

Lowrider, yes I have the Herbies dampers for components with the larger, softer contact material. I find using about 4 or 5 per speaker cable cleans up the sound, not to the degree of the tube dampers, but audibly nonetheless. I've only heard them applied to speaker cables in my system, and I expect their impact will vary depending on the system at hand. If you hold your speaker cable while the music is playing, do you feel any vibration?