Active Up2Stream Plinths for the CHN-50 Speakers

Please see This Post for a detailed rundown of our reference system.


When I built the MarkAudio CHN-50 speakers, the initial plan was to make them active by means of an Up2Stream AMP board integrated into the box. I ultimately decided to build them as passive boxes so as to hear them in the contexts of our reference system. I would make them active by means of a plinth containing the electronics, discussed herein.

Overall Speakers With Plinths, Remote And Power

The initial plan was a plinth in the same veneer as the speakers, made from stacked layers of MDF with a sharp angle sweeping down at the sides. These were ultimately abandoned due to my having underestimated the amount of veneer required and being unable to source a perfect match, and challenges in fitting the Up2Stream board. I decided instead on a pair of frames into which the speakers would sit, with the Up2Stream board mounted beneath leaving room for future expansion with additional electronics; a phono stage, for example.

Angle View Of Speakers On Plinths

The Oak I had to hand isn’t a perfect match for the veneer of the boxes, but works well enough and will blend as the colour changes with age. The plinths were given two coats of French polish after sanding to 320-grit, the surfaces then sanded lightly with 2500-grit paper once dry to give a smooth exterior finish.

Close Up Of Amp Plinth With Wires

The Up2Stream AMP board integrates the Up2Stream platform with a 2 x 50W class D amplifier, including remote control capability and a generous array of physical inputs and outputs besides the streaming features. Rather than attempt to fit a panel to the rear of the slimline plinth, I opted to fit the board at the front to allow access to the remote sensor and LED.

Amp Plinth With Led Lit

I left the plinth open at the top and bottom to allow airflow around the board, and also to allow access to the connectors. The wires protrude from holes at the rear making for a neat installation once the system is situated.

Back Of Amp Plinth

I couldn’t speak highly enough of the CHN-50s in my initial build review, and the same goes for the Up2Stream board. It’s the perfect match for these drivers. The onboard amplification can comfortably drive them to high levels without strain or distortion, but isn’t so overpowered as to be unlistenable at low levels too.

Rear Of Speakers On Plinths

I noted in my initial review that these boxes were capable of putting in a surprising low end performance when paired with the reference system, and am pleased to say this continues when paired with the Up2Stream AMP. Lows are deep and well defined with excellent control, the mids are expressive and the highs have a pleasing degree of sparkle while not veering too far toward brightness.

Front View Of Speakers And Plinths , No Grills

I’m hugely impressed with the Up2Stream platform. It’s the equal of many a commercial product and easily betters a number of them too. We’ll take a comprehensive look at the platform, including a detailed look at the Up2Stream AMP and Up2Stream Pro in future articles. These plinths finish the CHN-50 project off nicely, resulting in a compact active system capable of exceptional performance.


About Ashley

I founded Audio Appraisal a few years ago and continue to regularly update it with fresh content. An avid vinyl collector and coffee addict, I can often be found at a workbench tinkering with a faulty electronic device, tweaking a turntable to extract the last bit of detail from those tiny grooves in the plastic stuff, or relaxing in front of the hi-fi with a good album. A musician, occasional producer and sound engineer, other hobbies include software programming, web development, long walks and occasional DIY. Follow @ashleycox2

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