[rlmacklin]

Got some Herbies Audio Lab "UltraSonic" tube dampers (all with latest titanium C-ring) for cryoed Philips metal base GZ34/5AR4 NOS 1957 and for 2 Bendix 6900s in my Modwright SWL 9.0 Signature linestage and they cleaned up a slight haze (which was now apparent due to its absence) to allow better following sustain and particularly decay phase of each note and noticed some improvement in "definition," particularly in bass frequencies.

rlmacklin
 

[Wind Chaser]

Herbie's HALO's are a cheap tweak that works. 

His tube dampers on a Decware Zen kicked it up an obvious notch.

Too bad he don't make SS dampers. 

John

[modwright]

I wholeheartedly agree and fully support and recommend the use of Herbies products with our preamps and modified players.  His footers are excellent as are his tube dampers.  Our products all use output tubes that run hot, so I would recommend that you be sure that you get the high-temp pads for the dampers.

Dan W.

[gibheid]

Got some Herbies Audio Lab "UltraSonic" tube dampers (all with latest titanium C-ring) [...] They cleaned up a slight haze (which was now apparent due to its absence) to allow better following sustain and particularly decay phase of each note and noticed some improvement in "definition" particularly in bass frequencies.

Hi rlmacklin,

Had you tried the older "X" series tube dampers?  I use the hi-temp older ones just now and I'm trying to work out if there'd be any benefit in my upgrading. Audiophillia nervosa and all that...

Thanks for taking the time with this

 

[rlmacklin]

Previously I had Pearl "tube coolers" on the Bendix 6900s in my Modwright SWL9.0SE and replaced these with the latest Herbie's UltraSonics. 
I had looked at the variety of Herbie's tube damper products last year and inquired by e-mail which Steve Herbelin thought would work best for my Modwright tube complement.  Steve answered with his suggestions (which were for two different types of his tube damping products I think).  I never followed up, as I sent the Modwright linestage to Dan to upgrade to the tube rectified power supply.
I later revisited Herbie's tube damper webpage and saw that he had gone to the single UltraSonic line with titanium c-rings.  The web information indicated :
       "Homopolymer isolation pads absorb microphonics to provide a highly revealing soundstage with reduced grunge, glare and distortion. Fiberglass/carbon microfiber sleeves surrounding the pads enable a firm grip on the bulb glass. For continuous use to 525°.F (274°.C). Recommended for all audio vacuum tubes."

So I figured they were good for the higher temperatures, including the Philips metal base GZ34/5AR4 NOS 1957 rectifier tube as well.

Herbie's website indicates some older style tube dampers are available  "Closeout Special:Teflon, BlackBery and PEEK damping instruments" 

On the "more info/FAQ" page re the tube dampers, I found:

"
Q. Why have previous HAL-O versions been discontinued?

A. In addition to functional advantages like keeping a better grip on the tube glass, better adaptability to different tube diameters, and superior long-term heat resistance, our present lineup achieves a more-perfect sonic result than previous HAL-O versions, with superior cost-effect ratios. UltraSonics have the accumulative advantages of various HAL-Os without any of the individual drawbacks.

Q. Is it okay to mix and match different kinds of tube dampers?

A. Yes. UltraSonic and HAL-O damping Instruments complement each other very well. For example, a combination of PEEK HAL-Os on the input and driver tubes with UltraSonics on the power tubes can be ideal for a tube amp. Just be sure to keep stereo pairs the same. (Teflon and other previous HAL-O versions can also be mixed and matched with UltraSonic damping instruments.)

Q. Can I trade in older HAL-Os for UltraSonics?

A. Herbie's Audio Lab allows generous trade-in credit for upgrade products for a period of six months after the introduction of an "upgrade" or improved item, regardless of how old the original product is. Since it's been more than six months, this offer has expired for UltraSonic Titanium Damping Instruments. Older HAL-Os and other Herbie's products can be sold rather easily at Audiogon, eBay, etc. There's usually no need to "upgrade" however, because previous versions remain quite adequate for most audio and video systems. (Remember, all Herbie's products feature an unconditional lifetime warranty, so if any older HAL-Os are not working up to par, they will be replaced or "upgraded" at no cost.)   "


rlmacklin

[jeffreybehr]

I have found Steve Herbelin to be extremely helpful and generous.  I've been buying tube dampers from him since I got back into this crazy obsession several years ago, and he promptly solved some sizing and excess-heat problems and at no cost.  When I was using ASL 845-based SETs that used 2 6SN7s in the frontend, using the Ultrasonics reduced edginess somewhat*.  I still use the USs (mine came with the soft-plastic pads) on my Music Reference EM7 amps' 13EM7 tubes even tho all the 13EM7s I've ever heard are dead quiet.



* I'm no GEA; it's difficult for me to hear individual subtle differences like this.