Rotosound BS66 Billy Sheehan Custom (.043–.110): the signature bass string built for a D-Tuner
Reviewed by the Change Your Strings editorial team ·
Rotosound BS66 is Billy Sheehan's signature custom-gauge bass string set, .043 to .110, stainless steel roundwound. Developed with Rotosound in 1989, it's a Swing Bass 66 with a lighter G for even tension and a heavier .110 E built for his Yamaha Attitude bass's Hipshot D-Tuner. Bright, aggressive, and the exact set behind Mr. Big, The Winery Dogs, and David Lee Roth's Eat 'Em and Smile.
What this set is
Rotosound BS66 is Billy Sheehan's own signature gauge: a custom stainless steel roundwound bass set, .043 to .110, built with Rotosound around the specific needs of his touring rig. It shares its stainless roundwound construction with the standard Swing Bass 66, both made in the UK on James How's original machinery, but the gauge is custom: a lighter .043 G for even tension across the neck, and a heavier .110 E built specifically for the Hipshot D-Tuner on his signature Yamaha Attitude bass.
Sheehan has been a Rotosound artist since 1986, per the company's own history. Working directly with Rotosound, he helped develop this exact gauge, launched as the BS66 in 1989, and has used it ever since across Talas, David Lee Roth's band, Mr. Big, and The Winery Dogs. Read the full breakdown of his rig on his bassist profile.
On Rotosound's own product page:
They really sound great, there's a real organic feel to them, I've been to the factory where they're hand making them. It's such a part of the tone of everything I do! I'm a finger player and when my fingers grip the string the edges on the Rotosound's, because they're hand wound, grip really strongly so I can get a really good snap of power out of each note.
Bassist, Mr. Big / The Winery Dogs
Anatomy
- Model
- Rotosound BS66, Swing Bass 66 Billy Sheehan Custom
- Standard family
- Rotosound Swing Bass 66 (RS66LD standard, .045-.105)
- Gauge
- .043 – .110 (Custom)
- Gauge set
- .043, .065, .080, .110
- String count
- 4 strings
- Wrap wire
- Stainless steel, roundwound
- Coating
- None, uncoated
- Tone / output
- Bright tone, medium output, per Rotosound's own product spec
- Scale
- Long scale, 940mm (37 in.) ball end to taper
- Tension (Rotosound's own chart)
- G 40.94 lbs, D 51.30 lbs, A 43.80 lbs, E 42.25 lbs
- Developed
- 1989, working directly with Billy Sheehan; he's been a Rotosound artist since 1986
- Made in
- United Kingdom
- Package
- Single pack, signature graphics
BS66 Billy Sheehan Custom (.043–.110)
Why this one: Sheehan's own custom gauge, developed with Rotosound: a lighter G for even tension and a heavier .110 E built to handle his Yamaha Attitude's Hipshot D-Tuner without losing intonation.
Why this gauge is custom
Standard Swing Bass 66 ships .045-.105. Sheehan's BS66 moves both ends of that set for a specific mechanical reason, not just taste.
| Rotosound BS66 (Sheehan) | Rotosound Swing Bass 66 | Rotosound SH77 (Harris) | |
|---|---|---|---|
| Wrap material | Stainless roundwound | Stainless roundwound | Monel flatwound |
| Gauge | .043–.110 (custom) | .045–.105 (standard) | .050–.110 (custom) |
| Brightness | 9/10 | 9/10 | 3/10 |
| Built around | A D-Tuner drop to low D | General rock and prog tone | Iron Maiden's pick-attack gallop |
| Documented user | Billy Sheehan (Mr. Big) | Geddy Lee, Duff McKagan | Steve Harris (Iron Maiden) |
| Price tier | $$ | $$ | $$ |
The lighter .043 G isn't about tone, it's about feel. With a heavier E already in the set, a standard .045 G would feel comparatively floppy under the same hand, so Rotosound's own product page notes the lighter G "provides a more even string to string tension across the neck and makes bending easier." The heavier .110 E solves a specific mechanical problem: Sheehan's Yamaha Attitude has a Hipshot D-Tuner built in, a lever that drops the E string to D on the fly. Rotosound's own page says the 0.110 gauge "facilitates tuning down to a low D without the string bottoming out or loss of intonation," something a standard .105 risks under the same drop.
Best for
- Players with a drop-tuning lever (Hipshot D-Tuner, Hipshot Xtender, or similar) who need the low string to hold pitch and feel under a mid-song drop, the exact problem this gauge was engineered to solve.
- Rock and hard rock with a lead-bass style, Sheehan's own lane across Talas, Mr. Big, and The Winery Dogs.
- Prog and fusion players chasing a bright, cutting stainless tone that still leaves headroom for chording and two-handed tapping.
Worst for
- Players without a D-Tuner or similar hardware. The heavier E is built around that lever. Without it, the standard Swing Bass 66 (.045-.105) is the more balanced everyday set.
- Warm, vintage tone. Stainless roundwound is bright and aggressive by design. For Motown or vintage R&B warmth, a flatwound set fits better.
- Players who dislike an asymmetric gauge feel. A lighter G and heavier E changes the string-to-string tension curve compared to a standard progressive taper. Some players need a session or two to adjust.
Who plays it
Rotosound's own "As heard on" credits for this exact custom gauge:
Talas · debut album
Talas, Talas (1979)
Sheehan's first band, the regional Buffalo, NY act that built his reputation before Roth or Mr. Big.
David Lee Roth · 1986
Eat 'Em and Smile
Sheehan's bass sat alongside Steve Vai's guitar on Roth's first solo album after leaving Van Halen.
Mr. Big · 1991
Lean into It
Featuring "To Be with You," the Billboard Hot 100 No. 1 that's the commercial peak of Sheehan's career.
The Winery Dogs · 2013
The Winery Dogs
With Mike Portnoy and Richie Kotzen, Sheehan's active band today.
G3 Live
Joe Satriani, Steve Vai, Yngwie Malmsteen
Rotosound's own product page credits Sheehan's playing on this live G3 recording.
Sons of Apollo · 2020
MMXX
The prog supergroup Sheehan played in from 2017 to 2023.
Source: Rotosound's own BS66 product page, "As heard on."
Install and setup
- Loosen and remove old strings evenly. Don't drop the full tension on one side of the neck at once.
- Wipe the fretboard down. Stainless winding sheds a fine dust that finds every pore in unfinished wood.
- Install top-down (E first, then A, D, G), leaving about 3 wraps per tuning post on a long-scale bass.
- If your bass has a D-Tuner or similar drop lever, test the drop with the bass at pitch before you trust it live. The heavier E is built for this, but the lever itself still needs adjusting to your neck.
- Stretch each string by hand, retune, repeat 5 to 8 times. Bass strings need more stretching than guitar strings before they hold pitch reliably.
- Break-in: an hour or two of playing before the set fully settles and the initial brightness mellows into its working tone.
Verdict
If you play a bass with a drop-tuner and want the exact set built around that hardware, not just any bright stainless roundwound, BS66 is the direct answer: Sheehan and Rotosound engineered it for precisely this job. If you don't have a D-Tuner, the standard Swing Bass 66 (.045-.105) gives you the same tone in a more conventional, better-balanced gauge.