From Phil Jones Bass:

Powerful Small Combo 

The Compact Plus BG-450 is the pinnacle of PJB’s line of small and light weight powerful compact bass combos.  It is the same size as PJB’s C-4 speaker enclosure with a power amplifier that will reach up to 500 Watts with four internal 5” drivers.

The BG-450 contains the latest proprietary PJB chrome dome drivers which are the most efficient five-inch speakers ever engineered by PJB. The result is a perfect pairing of power and driver efficiency that makes it the best sounding 4×5 combo ever made by PJB and, remarkably, with less weight. It has an incredible punchy sound that cuts through air as “a knife through butter” with a solid and powerful low-end response normally associated with a much larger combo.

In the heart of this amp lies a formidable ultra-high-energy power supply using a Class D power amplifier for high efficiency which equals less heat and less weight, and is coupled with a pure Class-A, ultra-low noise pre amp. This combination completes a power section that achieves a massive dynamic range that allows the player to attain the best tone in any playing situation.  

The pre-amp design includes a single channel equipped with a variable gain input section that matches precisely with both active and passive basses. It also features a mute switch and the classic PJB 5-band precision EQ system that achieves the broadest range in tones imaginable with just 5 controls. This allows the player to effortlessly locate their perfect tone within seconds. 

The send /return FX patch can be blended to the direct signal allowing even more tonal opportunities. A secondary AUX input allows for practicing along with backing tracks via a 1/8” stereo jack. Back panel features include a Line Output jack that allows the BG-450 to be used in slave mode coupled with one or multiple amps, and a line input that provides the ability for an external pre-amp to be connected if desired.

The DI balanced out can be pre or post EQ and offers a ground lift to avoid problematic hum. Speaker output is via a Speakon NL4 socket perfectly matched to run a C4 or C8 cabinet. The amp can run on any AC voltage from 100 volts to 240 volts.

The Compact Plus puts out a punchy 300 watts into its own speakers and up to 500 watts when connected to an external cabinet. The BG-450 at max power will cover a wide variety of playing situations. For environments that demand much higher volume PJB recommends a BP-800 amp with PJB cabinets, or a BG-800 Roadcase as powerful alternatives.