HD621 HDMI Audio Processor
Perfect harmony

The Meridian HD621 HDMI Audio Processor is the link between your Meridian system and sources such as Blu-ray Disc®, satellite/TV receivers and gaming consoles with HDMI outputs.

The HD621 seamlessy integrates multiple HDMI sources – including 3D video – into your Meridian system. There’s even a programmable lip-sync delay to ensure sound and picture remain in perfect synchronisation. The HD621 also separates the HDMI signal from up to six sources into audio and video elements, maximising the audio quality and keeping it free of video pollution.


Key Features

Unique Meridian High Resolution up-sampling offers the best possible performance from all of your sources.

6 inputs and 1 output for simple, high performance HDMI switching.

Re-clocking of the digital audio signal removes timing errors for superior clarity and resolution.

Discrete and easy to install – 1U form factor with rack ears.



With its extensive Research and Development programme Meridian has pioneered the development of a host of innovative audio technologies many of which feature in today’s Meridian products.


Each sample of a digital recording must remain evenly spaced in time. Unfortunately, timing can vary, especially when reading discs. This is “jitter”, degrading music's sense of space and diminishing realism. Meridian's multiple “First In, First Out” buffering system minimises jitter, ensuring perfect timing and improved clarity. You enjoy a clearer feeling of the instruments and their interrelationship.

Filters are critical in digital audio. Commonly they introduce distortion and harshness because of "pre-ringing". Early digital recordings suffer from harshness too, due to primitive filters. After painstaking research, Meridian developed a special filter that avoids pre-ringing, so it can be steeper, cleaning up the effects of early filters. The result: a better, cleaner sound from recordings old and new.


Find out more about Hi-res Audio

Uses a complex digital filter to double the rate of samples from the source to improve resolution of the finer details in the record. This means that even with a standard source such as CD using our upsampling technology we are able to significantly enhance the listening experience.

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A patented Meridian audio format that combines high bandwidth, security and low jitter. MHR gets the highest possible sound quality in playback systems that use Meridian and enables the encoded transmission of PCM, MQA and DSD.

Meridian High Resolution Audio MHR.png

HD621 Audio Processor
Rack-Mount Variant


Power input (IEC connector)

DB9M Sub RS232 serial connector

BNC and DIN Meridian Comms

Six HDMI input sockets

HDMI output

8-channel MMHR digital audio out (RJ45)

8-channel coax digital audio out (4 x phono)


Power LED

6 x HDMI Input LEDs (selected input lights)


HEIGHT: 50mm [2.0in]

WIDTH: 440mm [17.32in]

DEPTH: 302mm [12.87in] plus connectors

WEIGHT: 4.5kg (10lb)


Internal universal power supply, 100–250V AC

Maximum power consumption: 40W

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