Guitar Amp UltraSonic: extra-duty microphonics control

Guitar Amp UltraSonic 9 Damping Instrument



Guitar amplifiers, especially combo amps, are torture chambers to vacuum tube microphonics. Herbie's extra-duty Guitar Amp UltraSonic Damping Instruments feature titanium C-rings and extra-soft, jumbo-size isolation pads for extra vibration control. Guitar Amp UltraSonics eliminate tube rattle, tube whistling, and microphonic oscillation that might be too severe for other damping instruments to handle.

These are superb damping instruments also for hi-end home audio, delivering pinpoint imaging and detail, outstanding transparency, delicate nuance and sense of "air," with highly punctual dynamics.

For use up to 482° F (250° C); scroll down for size listings.

Guitar Amp UltraSonic 9

Guitar Amp UltraSonic 9 Damping Instrument

Fits miniature 9-pin tubes and all tubes 3/4" to 7/8" diameter (19mm to 22mm), including 10GV8, 12AT7/ECC81, 12AU7/ECC82, 12AX7/ECC83, 12AY7, 12AZ7, 12B4, 12BH7, 12BY7, 12BZ7, 12DW7, 12FQ7, 2C51/396, 396A, 417, 5670, 5687, 5751, 5814, 5842, 5879, 5963, 6072, 6189, 6201, 6267, 6350, 6385, 6414, 6688, 6829, 6840, 6922, 6955, 6973, 6AN8, 6BL8, 6BM8/ECL82, 6BQ5/EL84, 6BQ7, 6BW4, 6CA4, 6C45, 6CG7, 6CS7, 6DE7, 6DJ8/ECC88, 6EU7, 6FQ7, 6GC7, 6GH8(A), 6GW8, 6H30, 6GU7, 6N1P, 6N3P, 6N6(P), 6P1T, 6U8(A), 6V4, 7025, 7044, 7058, 7062, 7119/E182CC, 7189, 7199, 7308, 7788, 7AU7, 7DJ8, 8416, Cca, E80F, EC86, ECC189, ECC803/S, ECC81, ECC82, ECC83, ECC85, ECC86, ECC99, ECL86, EF86, EL821, EL84, EL86, EM84, EZ80, EZ81, PCL82, PCL86, SV83, T6-1/2 bulb.

$28.69 ea.

Guitar Amp UltraSonic 25

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

$29.15 ea.

Guitar Amp UltraSonic 30

Guitar Amp UltraSonic 30 Damping Instrument

Fits narrow, straight-sided octal tubes and all tubes approximately 1-1/8" to 1-1/4" diameter (28mm to 32mm), including 12J5/GT, glass 12SJ7, 12SL7/GT, 12SN7/GT, 3CM, 4P1L, 5691, 5692, "slim" 5AR4 (G.E.), 5Y3, 5Y3GT, "wide" 5Z4, 6106, 6AH4, 6AU4GT, 6AU4GTA, 6AU5, 6BL7, 6CJ3, 6DN7, 6EA7, 6EM6, 6EM7, 6EW7, straight-sided 6F6G, 6FD7, 6FY7, 6H4GT, 6J8P, 6K11, "slim" 6L6, 6N8P, 6N9P, 6SF5-GT (glass tube), 6SH7, glass 6SJ7, 6SJ7GT, 6SL7, 6SN7, 6SN7GT-series (6SN7GT, 6SN7GTA, 6SN7GTB, 6SN7WGT, 6SN7WGTA), 6V6, 6V6GC, 6X5G/GT/WGT, 6Y6, 7355, C3G, C3M, EC8020, "narrow" EL34 (E-H,Mesa/Boogie,Telefunken, SED "Winged C," Svetlana, Tung-Sol), EL34B (Tung-Sol), GZ30, MT8 bulb, PL504, VT-231.*

$29.36 ea.

Guitar Amp UltraSonic 35

Fits standard, straight-sided octals and all tubes approximately 1-3/8" diameter (33mm to 36mm), 5AR4 (Amperex, Mullard), "slim" 6CA7, 6H6, bottle-shaped 6J5, standard 6L6/5881, 6L6B, 6L6GT, 6L6WGB, 6R7GT (glass), 6SF5 (metal shell), E34LS, standard EL34 (Philips, JJ, Mullard), GZ34, KT77.*

$29.74 ea.

Guitar Amp UltraSonic 40

Fits wide and bottle-shaped octals and all tubes approximately 1-1/2" to 1-5/8" diameter (37mm to 44mm), including 0A3, 0C3, 0D3, 1626, 27, 30, 37, "fat-bottle" 5AR4, 5AW4, straight-sided 5R4-types, straight-sided 5U4, 5V3, 5V4, straight-sided 5Y3GB, small-bottle 5Y3GB (Mazda), 5Y4GA, 5Z4G, 5Z4P, 6080, "slim" 6550, straight-sided 6AS7, 6C6, 6CA7, 6F8G, 6HB5, bottle-shape 6J5, 6JN6, 6L6GC (Mazda, JJ, GE, Tungsol), 6P3P, Sophia Electric "bottle" 6SL7 and 6SN7, 7027/A, 76, 84, 8417, 85, EL509, straight-sided GZ32, "Fat Bottle" EL34 (Big Bottle), KT90, PL509.*

$29.98 ea.

Guitar Amp UltraSonic 50

For all tubes approximately 1-3/4" to 2-1/8" diameter (45mm to 54mm), including 1610, 2A3 (RCA, Sovtek, Sylvania, Tung-Sol, Brimar), 26, 274B (Western Electric), 350B, 3D21A, 421A, 422A, 45 (RCA, Sylvania, TJ, Tung-Sol), 572-10, 5998, bulb-shaped 5R4-types, 5R4WGA/B (Tung-Sol), bottle-shape 5U4G, 5V4, 5Z3, standard and wide 6550 (E-H, RCA, SED, Svetlana, Tung Sol), 6550C, bulb-shape 6AS7, 6B4, 6B4G, 6C33C (upper portion of tube), bulb-shape 6F6G, bulb-shape 6L6G, 6N13P, 71A, 80, 807, 811, 814, C327 ("bulb" 27), CX4, bottle-shaped octals like AZ4, CV181/ECC32, CV181-Z (Shuguang), EL37, bottle-shaped GZ32, GZ33, KT66, KT88 (E-H, EAT, GEC, Gold Lion/Genalex, JJ/Tesla, SED, Shuguang, Sovtek, Svetlana), U52.*


Tube 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 pi (3.14).

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 larger sizes.

Additional information, including bulb sizes, on most tube types and brands can be found here:

[ Frank's Electron Tube Data Sheets ]

inches millimeters 

Changing gear? Heavy Duty UltraSonic isolation pads can be easily slid off one titanium C-ring and onto another. All sizes are interchangeable. 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. Heavy Duty UltraSonic Isolation Pads fit all Herbie's titanium C-rings, including extra-heavy gauge UltraSonics.

Titanium C-Ring Only (no pads)
UltraSonic sizes Mini thru 65
$5.89 to $16.95 ea.
(4 or more, one size: 10% off)

Heavy Duty UltraSonic
Isolation Pad Only

$7.95 ea.

All parts and materials made in USA

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