Jason used an Alembic Spoiler from 1989 up until he switched to Sadowsky in 1996-97. I believe he used one during the San Diego 1992 show from Live Sh*it: Binge & Purge, and it is featured prominently throughout the show and during his bass solo. I do not believe he used one for studio work.

Former Metallica bassist Jason Newsted used Dunlop Tortex Triangle Series Guitar Picks (0.50 - 1.14) during a performance with his bandmates at the 2009 Rock and Roll Hall of Fame induction ceremony.

In the video you can can clearly see Jason using the SSD JN-5 bass These basses were seen on "Wherever We May Roam" tour in 1994 and 1995 in 4 and 5 string variants.

Additionaly these basses are referenced here: https://whichbass.co.uk/know-your-bass-player/jason-newsted-bass-rig https://en.wikipedia.org/wiki/Jason_Newsted

These basses also appear in the list of Stuart Spector Designed basses: https://kcmusic.jp/spector/about-us/1424-2/

In this image Newsted can be seen playing on a Black Sadowsky Vintage Jazz 5-String.

In the Mid-90's carring heavy Alembic Basses were finally taking a toll on Newsted's sholder, Sadowsky Basses were built much lighter.

Newsed became a big supporter of these Basses as his original order in 1996 consisted of Four 4-Strings and Three 5-Strings, with an additional requirement that these Basses be completely Water and Sweat resistant.

A picture of some of Jason's guitars, pedals, and equipment.

In the bottom left a SansAmp Bass Driver can clearly be seen on his board.

at 1:36 Used during Black Album recordings

In the Early Years of Jason Joining Metallica, He, like Kirk and James had an endorsement with ESP. He briefly played a Surveyor 400 and an ESP Horizon II with custom Jazz pickups.

In the studio, Jason Newsted poses in front of an Ampeg SVT-VR. Another candid image of Newsted's concert rig using a couple of Ampeg SVTs.

This is an old Fender Telecaster Bass made sometime between 1968 and the early-mid 70s .(scroll down the page and you can see the pic of his tele bass.)

This a photo of Jason with his white Rickenbacker 4003.

In this photo, Jason Newsted is seen with an Alembic Exploiter bass.

Jason Newsted is listed as using a Music Man Stingray bass in the METALLICA - Encyclopedia Metallica's section on his equipment.

Jason Newsted's Alembic Europa Bass Guitar is custom-painted in "Almost Black," a unique color designed to appear black on stage while revealing intricate details up close. This is evident from a user-uploaded photo on Freewebs.

Jason Newsted uses the Boss CEB-3 Bass Chorus, as evident in the user-uploaded photo titled "newsted%2520rig.jpg" on Freewebs. The effect is notably heard during some of his solos.

Jason Newsted used a BC Rich Eagle Bass when he auditioned for/ joined Metallica, it can be seen in a photo in this article

Alembic Europa 5 with Series II electronics

In the photo, Jason Newsted is seen playing an ESP 400 Series PJ Bass. ESP, originally founded in 1975 as a spare parts company, is known for creating high-quality components for Fender and Gibson guitars. While some sources suggest Jason used an ESP Surveyor, the ESP 400 Series is distinguished by its traditional Fender headstock, as seen in this image.

Jason Newsted is shown using an Alembic Europa Series II 6-String Bass in a user-uploaded photo from Fcbass.

Jason Newsted is seen with a rare Hamer 8-String Bass, a model from approximately 1976, as shown in a photo shared on Instagram.

Jason Newsted is known to use Dunlop Tortex Triangle Guitar Picks, particularly the 1.14mm variant. While he frequently uses the 1.00mm picks, he also incorporates the 1.14mm and occasionally the 0.88mm picks into his playing. The source image on Equipboard shows a green Dunlop Tortex pick, which aligns with the 0.88mm gauge, but indicates his broader use of different gauges, including the 1.14mm.

In this photo, you can see Jason with a Road Worn P-Bass.

In this Megadeth concert on Youtube at part 1:01 Jason is seen playing a Jackson David Ellefson CB-X

At 5:11 in this video, when talking about his pedals, Jason Newsted mentions his "original flanger," bought "way back in the day," which he describes as just a "regular old purple flanger."

This bass was previously owned by Jason Newsted.

Jason Newsted has played Alembic basses, including the Alembic Elan Bass, as discussed in the Alembic Club forum.

Jason Newsted is known for playing the 1983 Alembic Spoiler, a standout bass in his collection, as discussed in the Alembic Club forum.

"Jason Newsted used a Wal Mk II 5-String Bass during several live performances and in the recording of various albums, as shown in a user-uploaded photo."

On the website dedicated to Jason Newsted, there is an image of him playing an ESP EXP Explorer guitar, identifiable by a Metallica sticker. This detail suggests it is likely his instrument, as James Hetfield is not known to use such stickers.

During Metallica's 1989 Seattle concert, featured in the video "Metallica - Live Shit Binge & Purge," Jason Newsted's Tech 21 SansAmp Classic is visible next to his wah pedal during the performance of "Blackened." The word "Classic" can be clearly seen on the pedal.

On ampeg's website it is written that jason newsted uses this amp.