The mkII version of this very popular motor drive is more powerful and has higher quality parts for even greater speed stability. The Speed Box II is a high-quality power line regenerator and a phenomenal upgrade for most turntables.  The Pro-JectSpeed Box II greatly improves speed stability, which means quieter, blacker backgrounds, excellent bass performance and a smoother, sweeter tonal balance. Highly Recommended!  

“Aside from providing better regulation of platter speed, the Speed Box II permits electronic switching between 33 1/3 and 45rpm. Everything tightened up: high-frequency transients sharpened, bass textures became far more musically recognizable, and overall “tunefulness� – the ability of the table to deliver the beats that make music sound real – became credible. If you’ve got a Pro-Ject or a Music Hall turntable, do yourself a favor and invest some money in a Speed Box Mk II! It makes the table sound twice as good. No kidding!�
Michael Fremer, Stereophile, July 2006

Hi-Fi News had this to say about the Speed Box in their May 2005 issue, 'The addition of a Speed Box proved very worthwhile, adding more control to the timing, a better sense of placement of the performers in a venue that seemed to have grown in size in all directions.'

6Moons.com said 'Truth be told, I really wasn't expecting much from this teeny weeny box...Aye Caramaba! The wee Speed Box was a minor revelation, even with a couple of thousand dollars of fancy power cables and AC conditioning, the Speed Box had a huge impact on playback!'

• Electronic push-button speed change between 33 and 45 RPM (No need to move belts!)
• Quartz-generated high precision electronic speed regulation
• All functions are microprocessor controlled

Specifications:
Quartz Oscillator: Speed Stability ±0.01%
Provides output of: 16VAC 500mA Max
Power Consumption: 3W Max
Dimensions (HDW): 1 ½ x 4 ½ x 4
Weight: 1Lb 4oz.

NOTE: SPEED BOX II will only work with the following Pro-Ject/MMF Models:
MMF-1.2 (models w/Detachable power supply only!)
MMF-5 & SE
MMF-7
MMF-9
Pro-ject 1, 1.2, 2, 6, 6.1
2Xperience
Debut (All models)
Perspective
RPM-4  
RPM-6 (RM-6SB comes with Speedbox)
RPM-9
Wood Classic (models w/Detachable power supply only!)
Xpression

Only models with mains socket 16V/AC power supply  

* The Pro-Ject Debut III E, Debut III/Phono SB, 1 Xpression III Comfort, 2 Xperience Comfort, RPM 6.1 SB, RPM 6.1 SB SuperPack and Xtension can not be used with the Speed Box II  

** 78 r.p.m. is not available for the Pro-Ject Debut III E, 2 Xperience, 2 Xperience Comfort, 2 Xperience SuperPack, 6 PerspeX, RPM 9.1, RPM 9.1 SuperPack, RPM 9.1X and RPM 10.