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Blackstar Unity 500 Review

After more than a decade serving the needs of guitarists, U.K.-based Blackstar opens their doors to bassists with a new series of amps.

 Recorded with Sandberg TM5 bass - Unity Bass U500 into Focusrite Saffire 6 interface into MacBook Pro using GarageBand.
Clip 1 - EQ at noon: Linear response with flat mode then to modern mode then to classic mode. Then flat setting starting with 6L6 response and ending with 6500 response.
Clip 2 - EQ at noon: Linear response with flat mode and cycling from fuzz effect to distortion to OD to chorus and ending with octave.


Power-packed, ready to travel combo with thoughtful features.

Heavy compared to its competition. Can sound a bit boomy and boxy. Takes some dedicated tweaking to find desired tones.


Blackstar Unity 500


Ease of Use:



Guitarists have been rocking through Blackstar products for over a decade now, but what about their bottom-dwelling brothers and sisters? Well, the U.K. company has answered the call. This year marks the introduction of Blackstar’s Unity Pro Bass System: an entire line of combo amps intended to suit the varying needs of working bassists. The series boasts a wide range of speaker and power configurations. Here, we tested the company’s flagship combo called the Unity 500.

A Full English
Blackstar established a solid foundation for the Unity 500 by combining two 10" Eminence Opus drivers with a 500-watt amp. These two features alone would be a dealmaker for any combo consumer, but the silver and black box contains a bevy of tonal components as well. Below the gain control is a voicing switch for the preamp. Selecting one of its three settings—classic, modern, or flat—not only changes the tonal character of the combo, but adjusts the EQ parameters to maintain sonic authenticity.

The drive channel functions more like a volume for the effect, as opposed to a control for the amount of distortion to the signal. Players can choose between overdrive, distortion, or fuzz, and then blend the driven sound with the clean signal. Keeping the drive control fully counterclockwise bypasses the effects feature.

I can’t report that Blackstar has actually captured tube feel, but I did get somewhat close to some classic tube tones.

Bass tones can also be seasoned with chorus and octave effects, which are engaged with a flick of a small switch on the top panel. The chorus rate is fixed, but its level in the signal can be adjusted with the corresponding dial located on the rear panel. Blackstar’s octave control is flexible as well. It, too, is in the rear panel’s effects-level section, and it offers players the option to double a note one octave up, an octave below, or both, depending on the small dial’s position.

Tube-emulation circuitry is nothing new, but Blackstar takes a different approach. By selecting linear, 6L6, or 6550, the response control on the top panel is intended to adjust the “feel” of the combo—as if one were playing through tubes. The Unity 500 also houses a footswitchable compression section consisting of a level dial and on/off switch.

Blackstar’s back panel is packed with more goodies as well. In addition to a conventional DI and effects loop, there is a mini jack for MP3 players, a headphone jack for silent practice, and a USB out to connect with a computer or recording device. The footswitch input is the connecting point for the included 2-way footswitch or an optional 5-way switch for deeper stomping options. The grand finale comes in the form of a cabinet-link output, which sends the signal from the Unity 500’s preamp to a powered extension cabinet. In fact, Blackstar has developed a sidekick for the Unity combos in the form of a 250-watt, 1x15 cab that transforms these rigs into portable powerhouses.

Unity Gains
It took a little extra oomph to pull the Unity 500 out of the box, as the almost-50-pound amp felt a bit weighty compared to other 2x10 combos. That said, the strong handle and rugged design instilled confidence it could handle the abuse of on-the-go musicians. Kudos to Blackstar for the Unity 500’s overall aesthetic, which is an eye-catching combination of classic style with a proud and powerful logo.

I took the combo straight to a blues jam, where the rig supported the house band with the help of a Fender Precision Elite. Setting everything flat, my ears were hit with a substantial amount of volume. There were ample amounts of lows, which at first overshadowed the slightly boxy midrange content, and highs that were snappy and sparkling.

I eventually found a pleasing balance via a hefty boost of the Unity 500’s mids. The other modes—modern and classic—provided dramatic changes in character. Modern gave me a strong scooped sound, while the classic setting delivered lighter low-end and present upper-mids.

As if these tonal transformations weren’t enough, the response dial ushered in additional sound shaping. Those who prefer the inherent sound of the Unity 500 will keep the dial on the linear setting. I found that the 6L6 setting provides a tighter, warmer tone with punch, and the 6550 brought full lows and a present upper-midrange that gave my sound aggression and authority. I can’t report that Blackstar has actually captured tube feel, but I did get somewhat close to some classic tube tones.

The effects were a bit hit-and-miss for me. The lush chorus effect sounded thick and pleasing when I washed blues ballads in tasty, modulated bass. The octave effect, however, was a little disappointing because I had trouble hearing it within the ensemble, regardless of setting. The different distortions were fun to use and definitely bring something to the table with three flavors to choose from, though the ability to adjust the amount of drive rather than having preset levels would have been welcome.

After plenty of tweaking and tonal experimentation onstage, I ultimately felt the Unity 500 sounded best in its flat, linear settings. The 10" speakers were unflappable and easily delivered bass notes through the exceptionally loud guitars and drums. Despite a couple of minor tonal challenges mentioned previously, I felt quite confident in the Unity 500’s performance throughout the three-hour show.

The Verdict
Blackstar’s Unity 500 foreshadows a bright future for the company’s bass-amplification offerings. It’s clear they put much thought into the features of the combo—most all which were delivered with a massive amount of power. Bassists looking to assert themselves within a loud ensemble should find Blackstar’s latest amp able to handle the task. If big sound from a small package resonates as an attractive combo to you, the Unity 500 is certainly worthy of a good look.

Watch the Review Demo: