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UltraSonic Rx Damping Instrument - Herbie's Audio Lab

UltraSonic Rx Damping Instrument

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UltraSonic Rx Damping Instruments help to bring out the microdynamic speed, linearity, and detail of your source material. Besides reducing microphonic anomalies, Rx allows a freer musical flow, curing a harsh and stealthy "electronics factor" or "dryness" that ultimately ails even some of the most finely honed audio systems. Your tube gear will achieve a fluid, dynamic musical potential like it was engineered to do.

Mildly spring-tempered titanium C-ring holds three modified PTFE isolation pads. Each pad holds a specially formulated polymer O-ring against the tube glass.

Herbie's most popular damping instrument, UltraSonic Rx is appropriate for all audio vacuum tubes, handling radiant heat up to a constant 482° F (250° C).

UltraSonic Rx-Mini: For sub-miniature and Nuvistor tubes approximately 3/8" diameter (9.2mm to 10.4mm), including 5703, 6111, 6112, 6020, 6021, 6088, 6CW4, 6DS4, 6DV4, 6N16B, 7586, 7587, 7895, 8056, 8058, T3 bulb.

UltraSonic Rx-7: For 7-pin miniature tubes and all tubes approximately 5/8" to 3/4" diameter (16mm to 19mm), including 0A2, 0B2, 0C2, 1S5, 12AE6, 12FK6, 12FM6, 12X4, 304B, 3A5, 3S4, 403A/B, 408A, 5591, 5651, 5654, 5654SQ/W, 6005, 6186, 6AK5, 6AK5W, 6AL5, 6AN4, 6AQ5, 6AQ6, 6AU6, 6BH6, 6C4, 6ER5, 6FG5, 6FQ5A, 6FS5, 6FY5, 6GK5, 6J1, 6J1P, 6J1P-EV, 6J6, 6N4, 6P17, 6X4, 6Z4, 7543, 9001, DCC90, DL92, EC90, EF95, M8100, OA2, OB2, OC2, SBA6. (Most 7-pin miniature tubes, at about 19mm diameter [3/4"], can also use UltraSonic 9.)

UltraSonic Rx-9: Fits miniature 9-pin tubes and all tubes 3/4" to 7/8" diameter (19mm to 22mm), including 10GV8, 12AT7/ECC81, 12AU7/ECC82, 12AV7,12AX7/ECC83, 12AY7, 12AZ7, 12B4, 12BH7, 12BY7, 12BZ7, 12DW7, 12FQ7, 2C51, 396, 396A, 417, 5670, 5687, 5751, 5755, 5814, 5842, 5879, 5963, 5965, 6072, 6189, 6201, 6267, 6350, 6385, 6414, 6519P, 6688, 6829, 6840, 6922, 6955, 6973, 6AN8, 6BL8, 6BM8/ECL82, 6BQ5/EL84, 6AW8, 6AW8A, 6BQ7, 6BZ7, 6BW4, 6C19P, 6CA4, 6C45, 6CG7, 6CS7, 6DE7, 6DJ8/ECC88, 6E5P/6E5PI, 6EJ7, 6EU7, 6FQ7, 6GC7, 6GF7A, 6GH8(A), 6GU7, 6GW8, 6H23N, 6H30, 6H6PI, 6N1P, 6N2, 6N2P, 6N23P, 6N30, 6N30P, 6N3P, 6N6/6H6PI, 6N6P, 6P1, 6P1P, 6P1P-EV/6II1II-EB, 6S19P, 6S4, 6U8(A), 6V4, 7025, 7044, 7058, 7062, 7119/E182CC, 7189, 7199, 7308, 7788, 7AU7, 7DJ8, 8416, CCa, D3a, E288CC, E80CC, E80F, E88CC, EC86, ECC189, ECC40, ECC802S, ECC803/S, ECC81, ECC82, ECC83, ECC85, ECC86, ECC99, ECF80, EL821, ECL86, EF184, EF800, EF86, EL821, EL84, EL86, EM84, EZ80, EZ81, M8162, PCC88, PCL82, PCL86, SV83, (T-6 1/2 bulb).

UltraSonic Rx-25: Fits all tubes approximately 1" to 1-1/16" diameter (23mm to 28mm), including metal 12SC7, 5693, "slim" 5Z4, "slim" 6AU4, metal shell 6F6, 6J5, 6R7, metal 6SC7, metal 6SJ7, "slim"6SN7, metal 6V6, 6X5.*

UltraSonic Rx-30: Fits narrow, straight-sided octal tubes and all tubes approximately 1-1/8" to 1-1/4" diameter (28mm to 32mm), including 0A3A (straight-sided), 1266, 12AX3, 12J5/GT, glass 12SJ7, 12SJ7GT, 12SL7/GT, 12SN7/GT, 3CM, 437A, 4P1L, 5691, 5692, 5852, "slim" 5AR4 (G.E., Sovtek/Reflektor, T-9 bulb), 5Y3, 5Y3GA, 5Y3GT, "wide" 5Z4, 6106, 68HC, 6AH4, 6AU4GT, 6AU4GTA, 6AU5, 6AX4GT, 6AX4GTA, 6AX4GTB, 6BL7, 6C5S, 6CJ3, 6D22S, 6DA4/6DA4A, 6DN7, 6EA7, 6EM6, 6EM7, 6EW7, straight-sided 6F6G, 6FD7, 6FM7, 6FY7, 6H4GT, 6J8P, 6K11, 6L6, 6N8P, 6N9P, 6R7GT (glass T-9 bulb), 6SC7 (glass tube), 6SF5-GT (glass tube), 6SH7, glass 6SJ7, 6SJ7GT, "slim" 6SL7, 6SN7, 6SN7GT-series (6SN7GT, 6SN7GTA, 6SN7GTB, 6SN7WGT, 6SN7WGTA), 6V6, 6V6GT (GE, Sylvania, Tung-Sol), 6X5G/GT/WGT, 6Y6, 7355, 7591, 7868, 7N7, C3G, C3M, EC8020, "narrow" EL34 (E-H, Mullard, SED "Winged C," Siemens, Svetlana, Telefunken, NOS Tesla, Tung-Sol), EL34/6CA7 (Svetlana), EL34B (Tung-Sol), GZ30, MT8 bulb, PL504, OA3A (straight-sided), T-9 bulb, VT-231.*

UltraSonic Rx-35: Fits standard, straight-sided octals and all tubes approximately 1-5/16" to 1-7/16" diameter (33mm to 36mm), including 5AR4 (Amperex, G.E., Japanese "Mullard" copy, Mullard, JJ, Shuguang), "slim" 6CA7 (Tung-Sol), 6H6, standard 6L6/5881, 6L6B, 6L6GT, 6L6WGB, 6SF5 (metal shell), 6V6GT (RCA), 6V6S (JJ), E34LS, ECC33, medium-diameter EL34 (Amperex, Philips, JJ, some Mullards, Valvo), EL34B (Shuguang), GZ34 (GE, JJ, Mullard, Philips, Raytheon, RCA), KT77.*

UltraSonic Rx-40: Fits wide and bottle-shaped octals and all tubes approximately 1-1/2" to 1-5/8" diameter (37mm to 44mm), including 0A3 (bottle-shape), 0C3, 0D3, 1626, 19, 27, 30, 37, 3DG4, 520B (near bottom of tube), 5881, "fat-bottle" 5AR4 (Amperex, Mullard, T-11 bulb), 5AW4, straight-sided 5R4-types, straight-sided 5U4 and 5U4-GB (T-12 bulb), 5V3, 5V4, 5Y3GB, 5Y4GA, 5Z4G, 5Z4P, 6080, "slim" 6550, straight-sided 6AS7, 6BY5/G/GA (straight-sided), 6C6, 6C8G, "Big Bottle" 6CA7 (E-H, GE, Sylvania, etc.), "Black Bottle" 6CA7-Z, 6F8G, 6HB5, bottle-shape 6J5 (ST-12 bulb), 6JN6, 6L6GC(E-H, Mazda, JJ, GE, RCA, Sylvania, Tungsol), 6L6WGC, 6LF6, 6P3P, Sophia Electric "bottle" 6SL7 and 6SN7, 7027/A, 7236, 76, 84, 8417, 85, CV3798, "Fat Bottle" EL34 (Big Bottle), EL509, G75/2D, straight-sided GZ32, "slim bottle" GZ37, KT90, OA3 (bottle-shape), OC3, OD3, PL509, QS150/40, VR105, VR75/30, VR75/40.*

UltraSonic Rx-50: For all tubes approximately 1-3/4" to 2-1/8" diameter (45mm to 54mm), including 10Y, 101F, 1610, 2A3 (Brimar, E-H, E-H Gold, RCA, Sovtek, Sylvania, Tung-Sol), 26, 274B (Western Electric), 307A, 35, 350B, 3A/110A, 3A/110B, 3D21A, 421A, 422A, 45 (RCA, Sylvania, TJ, Tung-Sol), 46 bottle-shape, 572-10, 5998, bulb-shaped 5R4-types, 5R4WGA/B (Tung-Sol), bottle-shape 5U4G, 5V4, 5Y3G (Sylvania), 5Z3, 5Z3P/A, 5Z4G (Brimar), standard and wide 6550 (E-H, GE, Philips, RCA, SED, Svetlana, Sylvania, Tung Sol), 6550A, 6550C, bulb-shape 6AS7, 6AS7G, 6B4, 6B4G, 6BY5/G/GA (bottle-shape), 6CA7-Z, 6C33C (upper portion of tube), bulb-shape 6F6G, 6H13, 6H13C, bulb-shape 6L6G, 6N13P, 6Y6G, 71A, 80 bottle-shape, 801/801A, 807, straight-sided 811, 814, C327 ("bulb" 27), CX4, bottle-shaped octals like AZ4, CV181/ECC32, CV181TII (Psvane 6SN7), CV181-Z (Shuguang), CV378 (Mullard), EL156, EL37, bottle-shaped GZ32 (Mullard), GZ33, KT120, KT66, KT88 (E-H, EAT, GEC, Gold Lion/Genalex, JJ/Tesla, SED, Shuguang, Sovtek, Svetlana), PX4, ST-14 bulbST-16 bulb, U52.*

UltraSonic Rx-55: For jumbo-size tubes 2-3/16" to 2-5/16" diameter (55mm to 59mm), including 101D/101F, narrow 211 (RCA), 211/VT-4C (GE), 2A3 (EML), 2A3-Mesh (EML), 274A, 300B "Balloon" (KR), Svetlana 300B, Takatsuki TA-300B, 45 (EML), 46 globe-shape, large bottle 5Y3GB (smaller Mazda uses UltraSonic 40), 80 globe-shape, "narrow" 805 (RCA, United), 829B, 841, 842, narrow 845 (Amperex, RCA), 845A (Shuguang), 872, GE211, "Big Bottle" GZ37, KT150 (specify size "60" in comments section of order form), SV811-10, ST-17 bulb, T-18 bulb.*

UltraSonic Rx-65: With plenty of flex to accomodate a wide range of tube diameters, fits giant tubes from 2-3/8" to 3" diameter (60mm to 76mm), including 101D "tennis ball," 101J, 102B, wide 211 (Sophia, TJ), 274B (EML, Shuguang, Sophia, Valve Art), 2A3-40W (JJ), 2A3 Meshplate (Sophia, TJ), 2A3 Globe Meshplate (Sophia, TJ), 2A3C (Shuguang), 300B (AVVT, E-H, EML, JJ/Tesla, Sovtek, KR, TJ/Full Music, Western Electric), 300B-XLS (EML, KR), Meshplate 300B (EML, Golden Dragon, TJ, Sophia, Shuguang, Valve Art), 300B Globe Meshplate (Sophia, TJ), 32B, Globe 45 (TJ/Full Music/Sophia), 45C, 45N, EML 45-mesh, 50, 520B, EML 5U4G-Mesh & 5Z3-Mesh,6C33C (wide portion of tube), 803, "wide" 805 (Amperex, Shuguang, TJ), 811A, 813, wide 845 (Sophia, Shuguang metal plate, TJ), 845B (Shuguang), F2A, GM70, PX25, ST-18 bulb, ST-19 bulbT-20 bulb.*

UltraSonic Rx-100: With extra-heavy-gauge stainless steel C-ring and four isolation pads, UltraSonic 100 dampers thoroughly tame microphonics in super-giant tubes 3-1/2" to 4-5/8" diameter (89mm to 118mm), including 833, KR T-1610 (Kronzilla), and tubes using T-36 bulb.

Changing Gear?  UltraSonic Rx isolation pads can be slid off one titanium C-ring and onto another. If you need a different size than what you have, spare C-rings are available, so you don't have to buy a whole damping instrument to change sizes.

Go to UltraSonic Rx C-rings

Go to UltraSonic Rx Isolation Pad Only

Customer Reviews

4.8 Based on 14 Reviews
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Lory W.
United States United States

UltraSonic Rx Damping Instrument

Purchased these for the PSVane 6SN7 driver (pre-amp.) tubes on my Feliks-Audio Elise. As the tubes are new production and free of audible microphonics, I wasn't sure how much benefit I would hear. Happily, they did indeed make a very impactful sonic difference. The amp. initially had a bit of mid-range "smear" with complex music, and bass was a bit loose. Both of these aspects are audibly improved with the dampers in place. The sound stage realism and instrument separation are also noticeably better, with a bit more treble sparkle and air, but no sibilance. These differences are not night and day, and can't make a mediocre tube amp. or shoddy tube set perform better than their intrinsic capabilities, but I do think the UltraRx dampers help me get the most out of my gear. I vary as to whether I find their appearance, tensioned gently around my tubes, rather handsome or a bit like my tubes visited the orthodontist, but most often I forget they are in place as unless you "stare" they are pretty neutral aesthetically. Importantly, for their very reasonable cost, the UltraRx dampers are a low risk thing to trial, and in my use case, a very worthwhile "bang for buck" addition.

Roger B.
United States United States

Herbie’s Tube Dampers—more Detail and Clarity in my system!

I have Herbie’s Tube Dampers on all my power amp tubes, both small signal and power tubes. In my system I am hearing more details, ambience and depth with the tube dampers on. They work by reducing the microphonics of the tubes caused from the vibrations of the transformers and sound waves. You can easily feel these micro vibrations by simply touching your tube equipment’s cabinet.

Roger B. verified customer review of UltraSonic Rx Damping Instrument
Rui Ribeiro

Surpassed Expectations

Heard a lot about it on Audiogon and decided give it a try replacing the original rings of the 4 output 6H30 tubes of my ARC Ref5SE. Just as other pals reported it is a huge improvement, not minor, and a really worth it. Big step in dynamics, soundstage specially width and height (wow), focus in instrument timbre, decay and attack, all producing an amazing better sense of being there. Almost unreal the soundstage height reached on some records, so as the realistic metallic timbre of the known difficult sound of cimbals and hi hats. Really worth the trouble of having to go and grab them out of customs (Portugal). Really happy. Herbie's dampers are no doubt a champion product.

Jaymes T.
Singapore Singapore

Herbie's Isolation Products

Hi Robert, I had received my second order of tube dampers, Tenderfoot and SuperSonic Stabilizers. Firstly, thank you very for your help with my initial order where I made a mistake on the sizing of the tube dampers, amazing honest customer service. I had tried for quite a while to "****" the resonance on my integrated amplifier which has a tubed preamp stage and nothing seem to work, can feel the cabinet "pulsating" with the music when I placed my hands on it. As a last ditch effort so I ordered the Tenderfoot and SuperSonic Stabilizers. Without much expectation as I had tried similar products before without any real results, I proceed to install them and to my surprise, they work! could barely feel any vibration on the cabinet even when I cranked the volume way past my usual listening level. The SuperSonic Stabilizers was an eye opener as well, placed one on the tube DAC and there was a noticeable improvement to the sound, not as much as with the amplifier but its there. Well done and thank you, your products worked as claimed. Once again thank you for the great customer service. Regards, Jaymes


UltraSonic RX Damping Tube

Excellent product ! Big improvment when placed at the top of my 6H30 tubes. Effect varies according to the position on the tubes. Really impressive.

Jameson O.
United States

Didn’t change much for me

In my particular situation - putting these on the very microphonic 4P1L tubes in a pre-amp - there was no discernible change in sound. Your mileage may vary. The quality of construction was nice, though.

Louis J.
United States

Herbie's is GEAT all around.

The website is easy to understand and use. Once ordered, delivery was faster than I expected and it was followed up by excellent customer service. I will certainly use Herbie's for all my "microphonic needs".

philip h.
United States

UltraSonic Damping

Addition of these removed a haze and tightens up mid range. Great product

Ralph G.
United States

adds life to my 845 mono amps

My amps use a pair of 845s. I was very satisfied with the way they sounded without dampening but adding Herbies RX-55 sized dampeners on these big tube made me aware of what I was missing. The sound is now more relaxed and differences in timbre are clearer. The quality of the space around instruments also seems clearer. At first this seems like overdampening but the more I listened, the easier it was to distinguish the interplay between instruments. It only took two tries to find the best location for each dampener. Half way down was too much dampening, but one third down yielded these improvements. The difference was not subtle between the two positions. Highly recommended. My tubes are Shuguang 845As, which aren't the most subtle of 845s but clearly benefited from some well-placed dampening.

Robert C.
United States

A Nice Little Tweak/Improvement for the Money with Durability as a Bonus

I installed an UltraSonic Rx Damping damper on each of the two 6h30 tubes that are in my Audio Research LS-27 preamplifier. I liked the idea that these dampers are guaranteed for life. It is also highly appealing that when I re-tube, that these dampers can be installed on the replacements. As a bonus, the sound cleared up a bit and became a little more focused. Since there is only two tubes/dampers involved, this was a no brainer tweak, that in the long run is cheaper than replacing the two silicone damping rings per tube that Audio Research supplies. Don't expect the "seas to part" on your audio system with these in place, but there was, none the less, a worthwhile incremental improvement in my system's focus, especially in the mids and highs that made installing these worthwhile. Recommended.

Henry K.
United States

Tube Dampers

The tube dampers have help to be clean up the sound of my amplifier and they look very cool.

Chris J.
United States

I’m a bit surprised

I wasn’t skeptical, but the UltraSonic Rx damping rings have tamed the 4P1L’s in my Smash preamp quite well.