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). Scroll down for size listings, from smallest to largest.
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.
Rx-Mini: $26.98 ea.
4 or more: $26.29
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.)
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-55: $31.89
4 or more: $30.99 ea.
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
Rx-65: $32.85 ea.
more: $31.95 ea.
With extra-heavy-gauge stainless steel
C-ring and four isolation pads, UltraSonic 100
thoroughly tames 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.
Rx-100: $40.49 ea.
4 or more: $39.89
diameters and shapes sometimes vary. To estimate your
tube diameter, just place a wooden or metal ruler
against the side of your tube and "eyeball"
the size – if you align your sight in a straight line to one edge of the tube and then in a straight line to the opposite edge, the measured difference in-between will be very close to the tube's actual diameter. Or measure the circumference and divide by
For tubes that fall
in-between UltraSonic sizes, smaller size is the default
recommendation (though either size will work). Tube size
data indicates "maximum" tube diameter; tubes
are often a little smaller than indicated. Titanium
C-rings have some flex to them to accommodate variation in
bulb diameters and can be bent to somewhat smaller or
information, including bulb sizes, on most tube types and
brands can be found here:
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.
Isolation pads are interchangeable among standard sizes
(UltraSonic Rx-Mini thru 50), and amongst heavy-gauge sizes
(UltraSonic Rx-55 thru 100). UltraSonic Rx isolation pads achieve
a full upgrade to "Rx" for standard UltraSonic Damping
Only (no pads)
UltraSonic Rx sizes Mini thru 65 $3.95 to $9.98 ea. (4 or more, one size: 10% off)
$7.95 ea. (12 or more: $7.49 ea.)
no-risk trial. If not satisfied, simply return any item within 90
days for a complete refund of the purchase price.
warranty.If anything ever goes wrong, simply
return any Damping Instrument to Herbie's Audio Lab and it
will be repaired or replaced and returned to you at no cost.