500R8 USB Audio Interface & 8-Slot 500 Series Rack
    • 28-in/30-out USB 2.0 audio interface
      • Low-latency USB 2.0 interface with high-stability and compatibility with a wide range of PC/macOS devices.
      • ADAT I/O (16/16 channels @ 44.1/48kHz, 8/8 channels @ 88.2/96kHz)
      • S/PDIF I/O
      • 5-pin MIDI I/O
    • High-performance A/D-D/A conversion
      • Dynamic Range: 121dB A-weighted, AES17 method, 20Hz - 20kHz
      • Frequency Response: -1dB, 2.2Hz to >80kHz
      • THD+N: <0.00032% (-110dB) @ -4dBFS, 20Hz - 40kHz, 1kHz, A-weighted
      • Max I/O Level: +24dBu
    • Master reference-quality internal clock
      • Capable of 44.1, 48, 88.2, 96, 176.4, and 192kHz operation
      • <0.5ps of jitter
      • Dedicated Word Clock Input and Output via BNC
      • External sync options using Word Clock BNC, S/PDIF, or ADAT
    • Monitor controller with talkback
      • Speaker A/B switching, Mono check, Dim, Mute, and 28-segment peak meter
      • Dedicated talkback input with phantom power, push-to-talk activation, and automatic routing to all headphones and C.A.S.T. facilities
      • Easy-access illuminated front panel controls for all monitor controller functions.
    • Analogue summing mixer
      • 8-into-2 analogue summing mixer with +26.5dBu of headroom, dedicated ADC, and balanced 1/4" jack outputs
      • C.A.S.T. link port for increasing summing mixer to 16-into-2 using Cranborne Audio 500ADAT
    • Zero-latency artist mixer 
      • Zero-latency analogue artist mixer with physical level/pan controls per channel and DAW return blend controls
      • 2 high-power headphone outputs with independent blend and level controls
    • Reference-Quality Headphone Outputs
      • THD+N: <0.0006% (-104.4dB) @ 20dBu, 1kHz, A-weighted, 300ohm load
      • Output Wattage (1kHz): 250mW x 2 @ 600 ohms, 650mW x 2 @ 220 ohms, 1.21W x 2 @ 100 ohms, 500mW x 2 @ 32 ohms
      • Frequency Response: 1dB, <1Hz to >70kHz
    • High-current 8-slot 500 series rack
      • 250mA current per-slot with 2A total for all slots
      • XLR inputs, XLR line outputs, and TRS Inserts (pre-ADC) per 500 series slot
      • Module source switching options to send Analogue, USB or external C.A.S.T. signals through your favourite 500 series modules
      • Module bypass switches per-slot allowing 500R8 to be used without 500 series modules inserted. 
    • C.A.S.T. Compatible
      • C.A.S.T. ports per channel for relocating analogue I/O around studio using passive or active C.A.S.T. breakout boxes via standard shielded Cat 5
    • 24v, 5a external locking power supply
      • External power supply for improved analogue audio performance and heat dissipation.
    • Designed and Engineered in the UK
      • Each and every 500R8 is extensively tested by a team of dedicated engineers to ensure reliability and consistency.

All specifications are typical performance unless otherwise noted. All specifications are subject to change at any time. Tested with Audio Precision APx555 at 192 kHz internal sample rate and internal clock. HF response of digital measurements will vary depending on sample rate selected during recording.

Digital Performance

A/D Conversion

Test Signal Path

XLR Input - 500 Series A/D Converter - APx555 (ASIO)

Frequency Response

-1dB, 2.2Hz to >80kHz


-0.05dB, 20Hz to 20kHz


<0.00032% (-110dB) @ -4dBFS, 20Hz - 40kHz, 1kHz, A-weighted


<0.00065% (-104dB) @ -1dBFS, 20Hz - 40kHz, 1kHz, A-weighted


<0.00014% (-117.5dB) @ -8dBFS, 20Hz - 40kHz, 1kHz, A-weighted


<0.00023% (-113dB) @ -4dBFS, 20Hz - 40kHz, 1kHz, A-weighted


<0.0006% (-105dB) @ -1dBFS, 20Hz - 40kHz, 1kHz, A-weighted

Dynamic Range

121dB A-weighted, AES17 method, 20Hz - 20kHz

Max Input Level


D/A Conversion

Test Signal Path

500 Series D/A Converter - Insert Send - APx555 (ASIO)

Frequency Response

-1dB, <1Hz to >61kHz


-0.05dB, 20Hz to 20kHz


<0.0003% (-110.5dB) @ -4dBFS, 20Hz - 40kHz, 1kHz, A-weighted


<0.0004% (-108dB) @ -1dBFS, 20Hz - 40kHz, 1kHz, A-weighted


<0.00014% (-117.5dB) @ -8dBFS, 20Hz - 40kHz, 1kHz, A-weighted


<0.00018% (-115dB) @ -4dBFS, 20Hz - 40kHz, 1kHz, A-weighted


<0.00036% (-109dB) @ -1dBFS, 20Hz - 40kHz, 1kHz, A-weighted

Dynamic Range

121dB A-weighted, AES17 method, 20Hz - 20kHz

Max Output Level





Analogue Performance

Line Outputs (Speaker B, Aux, Mix)

Test Signal Path

DAW 2 D/A Converter - Line Outputs - APx555 (Line In)

Connection Type

1/4" Jack, Impedance Balanced

Output Impedance

150ohm balanced, 75ohm unbalanced

Max Output Level


Freq Response

-1dB, 1.4Hz to >80kHz


<0.003% @ +18dBu, 1kHz

Dynamic Range

105dB A-weighted, AES17 method, 20Hz - 20kHz

Noise Floor

<-93dBu A-weighted, 20Hz - 20kHz, (Unity Gain)

Speaker A Output

Test Signal Path

DAW 2 D/A Converter - Speaker A Line Output - APx555 (Line In)

Connection Type

XLR, Balanced, non-floating

Output Impedance

150ohm balanced, 75ohm unbalanced (pin 3 unconnected)

Max Output Level


Freq Response

-1dB, <1Hz to 70kHz


<0.0016% @ +24dBu, 1kHz

Dynamic Range

109dB A-weighted, AES17 method, 20Hz - 20kHz

Noise Floor

<-92.5dBu A-weighted, 20Hz - 20kHz, (Unity Gain)

Talkback Input


30dB Fixed Gain Preamp, +20dB Analogue Trim

Phantom Power

Always On

Summing Mixer

Test Signal Path

XLR Input - Summing Mixer Bus (Unity) - A/D Converter 9/10 - APx555 (ASIO)

Freq Response

-1dB, 2.25Hz to >80kHz


-3dB, 1.2Hz


-0.5dB, 3Hz


<0.0007% @ +23dBu (-1dBFS), 1kHz


<0.0003% @ +14dBu (-10dBFS), 1kHz


<0.0004% @ +20dBu (-4dBFS), 1kHz


<0.00055% @ +23dBu (-1dBFS), 1kHz

Dynamic Range

108dB A-weighted, AES17 method, 20Hz - 20kHz

Noise Floor (A/D 9-10)

-108dBFS A-weighted, 20Hz - 20kHz

Max Contribution Level


Pan Law


Noise Floor (Mix Output)

-90dBu, A-weighted, No channels routed


-89.5dBu, A-weighted, 1 channel routed (Unity)


-84dBu, A-weighted, 8 channels routed (Unity)

Headphone Amp

Test Signal Path

DAW 2 D/A Converter - Headphone Output - APx555 (Line In)

Frequency Response

-1dB, <1Hz to >70kHz


<0.0006% (-104.4dB) @ 20dBu, 1kHz, A-weighted, 300ohm load


<0.00085% (-101.4dB) @ 20dBu, 1kHz, A-weighted, 300ohm load

Output Impedance

0.33 Ohms

Output Wattage

250mW x 2 @ 600 ohms, 1kHz


650mW x 2 @ 220 ohms, 1kHz


1.21W x 2 @ 100 ohms, 1kHz


500mW x 2 @ 32 ohms, 1kHz

Dynamic Range

114.5dB A-weighted, AES17 method, 20Hz - 20kHz, 300ohm load

Noise Floor

-93.5dBu A-weighted, 20Hz - 20kHz, 300ohm load

System Performance

Analogue Path Phase Performance

Test Signal Path

XLR Input - Empty 500 Series Slot - Summing Mixer Bus (unity) - Monitor Bus - Speaker A Output - APx555 (Line In)


<3.6° @ 20Hz, <22° @ 20kHz

Test Signal Path

XLR Input - Empty 500 Series Slot - Summing Mixer Bus (unity) - Mix Output - APx555 (Line In)


<1.5° @ 20Hz, <11° @ 20kHz

Test Signal Path

XLR Input - Camden 500 Preamp (Mic Mode, 6dB Gain) - Summing Mixer Bus (unity) - Speaker A Output - APx555 (Line In)


<3° @ 20Hz, <13.5° @ 20kHz (Preamp mic mode, 6dB Gain)

Digital Round-trip Performance

Test Condition

500 Series D/A Converter - 500 Series A/D Converter - APx555 (ASIO)

Dynamic Range

118dB A-weighted, AES17 method, 20Hz - 20kHz


<0.0004% (-108dB) @ -4dBFS, 20Hz - 40kHz, 1kHz, A-weighted


AC Requirements

100V – 240V AC, 50 – 60 Hz

Total Power Consumption

24v, 5A DC, 120w

500 Series Slot Current

250mA per rail

Total Available 500 Series Slot Current



Operating Temperature

+1 to 30 degrees Celsius

Storage Conditions

-20 to 50 degrees Celsius




481mm(19"), Rackmount


185mm(7"), 4u



Unit Weight


Shipping Carton









Driver Installers (Windows Only):
500R8 is class-complaint on macOS and does not require drivers to operate.


Download Driver (Windows)

Studio In A Box

500R8 is home to 8 of your favourite 500 series modules. It's also a 28in/30out USB audio interface, monitor controller, and discrete analogue summing mixer.

Analogue Character

Configure 500R8 to suit your desired analogue flavour. Fill it full of vintage-style 500 series preamps when you're recording drums, clean and pristine preamps when you're recording strings, or EQ/Compressor/saturation 500 series modules when it's time for mixing. 
...Meets Digital Precision
Connect 500R8 directly to your PC/Mac and capture every last nuance of your analogue sources with reference-class AD/DA conversion and superior internal clocking. Effortlessly pass audio between analogue and digital worlds without digital artefacts that colour and degrade your recordings. 

The Studio Essentials

500R8 has everything you need to build your dream analogue/digital hybrid studio. Each element has been carefully considered and designed to give you best of everything combined into a package that is intuitive (and fun) to use.


USB Audio Interface
Connect directly to your PC/mac via USB and utilise 500R8's built-in 28-in/30-out USB audio interface for recording and playback directly to/from your chosen DAW.


Monitor Controller
Switch between two sets of speakers, toggle Mono sum, Mute, Dim, and Talkback facilities whilst monitoring the peak level of your mix with 28-segments of LED detail by using the built-in, high-headroom monitor controller.


Zero Latency Artist Mixer
Monitor live sources in the analogue domain with zero latency by using dedicated mix level and pan controls per-channel combined with our seriously high-powered headphone amps.

Discrete Summing Mixer
Elevate your mix with analogue character and sum 8 USB sources through your 500 series modules and into the discrete analogue summing mixer to be summed and recorded back into your DAW as a stereo track.


"...500R8 measures extremely well... easily on a par with the best standard USB interfaces currently on the market."

"it’s a top-notch audio interface, a capable 500-series host chassis, an expandable analogue summing mixer, and more besides”

"...they have a right to be very proud of this flagship product."

"The bottom line is that this melting-pot of an interface is a genuine triumph"

Read More

Sound On Sound

"...it truly is a very well thought out mini-studio that packs a ton of punch has loads of versatility and expandability"

"Every "studio-head" friend that comes by and sees the unit is immediately intrigued and impressed by its sonic, form factor, and capabilities"

Read More

Tape Op

"...this is one impressive piece of kit"

"Despite such broad functionality it's surprisingly user-friendly and intuitive, not to mention reasonably priced."

"...the sound quality is stellar...Cranborne Audio did a great job of designing its feature set that's both practical and comprehensive"

Read More

Mix Magazine

World-Class Conversion & Clocking

To make your 500 series modules shine on your digital recordings, our conversion had to be best-in-class. We squeezed every possible .1dB of performance out of 500R8's converters to ensure that the only thing colouring your recordings are your mic placements, mixing decisions, and choice of 500 series modules.

Dynamic Range:
121dB A-weighted, AES17 method, 20Hz - 20kHz

Frequency Response:
-1dB, 2.2Hz to >80kHz

<0.00032% (-110dB) @ -4dBFS, 20Hz - 40kHz, 1kHz, A-weighted

Clock Jitter:
<0.5 Picoseconds


Deep 500 Series Integration

Configurable Front End
Mix and match your 500 series modules to find the best combinations during recording, and mixing to help create your own signature, analogue sound.

Source Select
Re-patch your 500R8 at a flick of a switch. Dedicated source select switches for each 500 series slot adjusts the signal routing to send Analogue, C.A.S.T. or USB sources through each your modules.

Enough I/O For Any Hardware
500R8 to integrates with all of your analogue/digital hardware. Patch in 500R8 with your own converter or integrate your 19" rack gear with dedicated TRS insert jacks per slot.

No Modules? No Problem
Bypass unused 500 series slots using 500R8's dedicated slot-bypass switch and you can use all of the available analogue paths for recording whilst you continue to build your 500 series collection.


Ready For More?

When you've run out of available recording channels on 500R8, our 500ADAT comes to the rescue. Connect 500R8 and 500ADAT together via ADAT and now you have 16 channels of 500 series modules to work with. during recording and mixing. Whilst 500ADAT offers the same performance as 500R8, any 3rd party ADAT expander is also compatible.

More Recording Channels
Record up to 16 channels directly through independent 500 series modules and directly into your DAW for processing. 

More Summing Channels
Play back instrument groups/stems into all 16 available 500 series slots for summing using our C.A.S.T. link connector.

Expandable Via C.A.S.T. Rewire your studio using Cat 5

Fitted with our C.A.S.T. system, 500R8 is compatible with our N22 and N22H C.A.S.T. breakout boxes that cast-away excess cabling spaghetti and offers a cost-effective, low-maintenance, plug-and-play solution to rewire your studio. C.A.S.T. transports 4 channels of balanced, analogue audio over shielded Cat 5e, Cat 6, and Cat 7 cable directly to the location where it is needed in your studio. Create vocal booths, isolation booth, or run our a microphone to the hallway for ambience, C.A.S.T. is the best way to expand your 500R8 and get the most out of your studio space.

Send/Receive Audio From C.A.S.T.
Simply connect N22 or N22H to 500R8 using shielded Cat 5e, Cat 6, or Cat 7 cable and mics/sources connected to the breakout are patched directly to the slot inputs of 500R8. At the same time, the monitor mix created on 500R8 (including talkback) is sent through the same cable, directly to the outputs of the connected breakout.



Fully Compatible With Microphones and 48v
If you have preamps installed into 500R8, C.A.S.T. can transport their 48v phantom through the C.A.S.T. connection via Cat 5e, Cat 6, and Cat 7 and directly to condenser/active microphones connected at the end. C.A.S.T. is completely plug-and-play and works at distances up to 100m for maximum flexibility and convenience.


Learn More About C.A.S.T.


N22 N22H
Home Grown Designed and Engineered In The UK

Housed in a 4U, 19" rack mountable steel frame, 500R8 lends it self perfectly to mobile recording setups. We tried to think of everything, even the rack ears support three unique mounting methods. You can recess 500R8 into the rack to protect the front panel controls during travel; you can also take those same rack ears and re-orientate them to become a carry handle.

Home Grown
500R8 is designed and engineered in the UK and every unit that leaves the factory is thoroughly tested to provide years of trouble-free and dependable service.

Built And Designed With Passion
We don’t take shortcuts. We don’t compromise. We don’t accept “good enough.” We’re just like you. We’re musicians. We’re audio engineers. 500R8 is a product we're very proud of, and we hope you will be too.

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