"Quality, simplicity and accuracy: all you need to monitor your work"
"The digital crosspoint can be used to make a digital record path, with digital inserts and distribution."
Crookwood Products: C2 Monitor controller
The C2 is the first product in our new C series Monitor Controllers.
It is the only product on the planet to have a high performance analogue monitor controller, together with a mastering quality Digital to Analogue converter (DAC) and an inbuilt 8x8 Digital crosspoint router!
The analogue monitor has the widest range of features on the market, as well excellent specs and a very neutral sound.
The internal DAC is SRC based, so it's "jitter immune", and is identical to the model we use in our mastering consoles.
The unique feature of adding a digital crosspoint router allows you to use the C2 to join together all your digital gear together without a patch. You can copy from one machine to another, form a record chain, or just distribute multiple copies of a signal without degradation.
The combination of features, plus the small footprint of the remote control panel, makes the C2 ideal for modern monitoring in a digital age, where the majority of machines you work with are digital, not analogue.
A C2 Control Panel.
All About the C2 
The C2 is a cost effective quality box for monitoring up to 1 analogue and 8 digital sources over 3 sets of speakers and headphones, and has all the features you'll need for accurate stereo monitoring and routing of digital machines.
It's configured so that you can easily select a digital source for monitoring and route this signal to our excellent internal, quality DAC. Optionally you can use your own external converter if you prefer. You can also use the 8x8 crosspoint completely freely to route any digital source to any digital destination - ideal for forming a separate digital record path. A separate analogue input allows you to monitor an additional analogue machine like a 1/2" ATR.
It's based on our igloo range - the most powerful and flexible monitor/ routers available, and uses the same processing cards. By optimising the features set, we've kept the price low, and the C2 represent good value for money. If you need additional features however, the igloo's will satisfy all your needs - please call us for more details.
The C2 has all it's audio IO on multiway connectors on a 1U box, which can be mounted remotely from it's control panel. We can provide XLR breakout cables or XLR patches if you prefer them. In addition you can specify other parts from the igloo range including precision VU meters & talkback panels.
Key Features
Inputs
- 2 balanced analogue inputs, each one relay selected for the best sonic performance. The primary analogue input is active whenever a digital source is selected and is wired to our internal Crookwood DAC. As an option you can wire it up to an external DAC.
- An 8x8 digital AES/SPDIF crosspoint router with transformer coupled inputs and outputs, coping up to 24 bit 192KHz digital audio. The main interface is configured as a 8 input selector for our internal DAC, so you just push the button of the digital source you want to listen to.
- Each source can be trimmed with fine precision (1/4 of a dB) to remove level differences between them as you monitor, so you can A/B them accurately.
DA Converter
- SRC based converter decouples the digital input from the sensitive converter making the DAC " jitter immune". This means excellent sound quality whatever the source.
- Our DAC runs at 200kHz off a local clock, and will convert any input signal up to 192KHz
- Designed to integrate to our monitor circuits, the analogue circuitry is absolutely minimal and keeps to our completely balanced philosophy.
- It locks up to digital sources really quickly, and automatically mutes the monitors to avoid any clicks.
Crosspoint Router
- 8 inputs, and 8 outputs. One of the 8 outputs feeds the internal or external DAC.
- Each input is transformer coupled to isolate the digital signals from the rest of the ciruitry.
- Each output is separately buffered, and loading it will not affect another output.
- Each input and output can be internally selected to be SPDIF or AES compatible.
- It is asynchronous, so you don't need to route wordclock at the same time, and you can route signals of different sample rates or bit depths at the same time.
Speaker Controller
- 3 speaker outputs plus a headphone output.
- Each speaker or headphone output has a individual output level.
- Precision volume control, stepped and repeatable, with dB levels shown in an LCD panel.
- 1dB volume control steps, with 0.25dB trim steps over a +/- 10dB range.
- K cal feature, so you can work against a calibrated master volume level.
- Balanced buffered, analogue meter output, pre volume control.
- Cut left, cut right, mono sum, mono difference and phase reverse checks.
- Master cut and dim. Dim level can be preset
Mechanics
- The C2 is based around a 1U 19" steel box, with no front panel controls, and multiway audio connectors on the rear panel. This "Brain" rack holds the audio processing cards, power supply and control processor.
- A separate compact control panel is connected to the rack by a small data/power cable, and can be remotely mounted 7M (22ft) away from the rack. Further distances can be accommodated if a small, optional local power supply is used.
- A backlit paper label is used to label each button (IO connection). This label is visible in poor or good light, providing excellent signing. We provide a MS Word template to allow you to print your own labels so you can label your panel to match your own equipment.
- The compact panels can be mounted into studio furniture, or optionally into a 4U 19" space, or into a wooden pod, freestanding on the worktop. They are only 3cm (1.5") deep, so are very easy to fit.
Options
- Local Power Supply. The front panel is normally powered from the rack. if the rack is more than 7M (22ft) away, we recommend using a small local PSU to power the front panel separately.
- Talkback Panel. This matching panel allows you to talk to a destination. It can mix talkback with a stereo cue feed, or replace it. A compressor on the talkback mic amp increases intelligibility.
- VU Meter Panel. This matching panel houses 2 large precision Sifam VU's. An impedance matched meter attenuator allows you to ensure the VU's work within their range, no matter what your house operating levels are. Click here for more details.
- Mounting Kits. The remote panel can be mounted into a 4u 19" space, or into a movable wooden pod placed onto the worktop.
Technology
We've been making remote controlled audio devices since 1992, and are the world leaders. The key to making a great audio device is the choice of circuit elements to do the remote bit. We chose relays from day one, which while expensive and bulky, are the perfect device - no distortions, delays, frequency or level limitations (within reason!). We use relays for all switches and gain elements. The gain circuits in particular act as stepped, switched attenuators, giving perfect repeatable control.
One of the benefits of remote control is that you can place the relays exactly where you want them on the circuit board. Normally with a conventional design, you have got to lay out the front panel first, and then squeeze the electronics around the front panel knobs and switches. Or use lots of wire to join the front panel to the electronics. Now by being able to design the way you want, the whole circuit becomes much smaller and linear - a definite boost for sound quality!
Our digital routing is done with discrete logic parts to provide a high specification router. Transformers are used on input and output for complete digital isolation. They are the same parts as we use in our Digi iRou routers, and route digital audio transparently.
The other unusual feature is our addiction to fully balanced circuitry. Normally designers just put balancing circuits on the inputs and outputs of a box. We keep our circuits fully balanced from input to output, making the design completely symmetrical. This advanced symmetry means that any distortion generated by the design on the hot phase, are matched by an identical distortion, generated in anti-phase on the cold phase. This approach removes the distortions by simple subtraction.
What other design features have we got? Every element of the design has been thought about in depth, but here's a few other details:
- High quality front panel components. The knobs and switches on the front panels are high quality, log life-time parts. You can feel the difference between these parts and those on other competitor's products. We have got products still in every day use for over 15 years.
- Wide frequency response. In order to get good HF distortion figures, you need a high frequency response. However too wide allows RFI to enter the box. We use a wide frequency response, tailored by passive rolloff filters for RFI protection.
- Local Power Supply. Each audio processing card has it's own power regulators, spreading the load across several cards for better heat management. The local regulators also provide better power performance, than one big regulator, powering the whole device, as is common in most other pre amps.
- Intelligent control. There is a small processors on each processing card. This processing power lets us do lots of little clever things, like muting the outputs when you change speakers (stops big thumps).
- Wide AC power range. The C2 has been designed to work of a wide range of power supply variations. This means the C2 is less susceptible to brown outs on the mains power.
- AC Power filter. An expensive power filter is used on the power input to stop mains spikes and noise from getting into the audio.
- Modular design. The whole electronics are based on modules, making them easy to upgrade, repair, fault find and exchange.
Specifications
Electronics
- Noise. >-98dBu at any gain.
- Analogue S/N. >125dB
- Digital S/N. >120dB A weighed.
- THD. >0.001% @ 0dBu from DC to 20kHz, 22kHz bandpass filter.
- Max Analogue Ip Levels. +27dBu.
- Max Analogue Op Level. 27dBu on output: clips on output first.
- DAC 0dbFs Level. Preset to be +22dBu.
- Frequency Response. <0.05dB @ 20kHz, -3dB @ 400kHz and 0.5Hz, any gain, ref 1kHz. DAC card is -3dB at 60KHz.
- Digital signals. 32-192KHz single wire to 24bits, 24MHz signals. Each output is fully buffered.
Mechanical
- Weight 6Kg
- Dimensions. 5Hx50Wx40D cm, controller is 17Hx10Wx3D cm.
Prices
The C2 starts from only GBP 1250, ex VAT, FOB Crookwood.
FAQ
Can I use unbalanced -10 inputs with the console?
Yes. The input trimmer will let you boost the level for monitoring, so you can compare this -10 input with normal balanced sources.
Can I drive unbalanced power amplifiers with a C2?
No. The design of the true balanced amplifiers mean they must drive a balanced input. Anyway, it's unwise to run a length of unbalanced cable, due to ground noise injection. You can use the headphone output however if you need to.
Can I form a digital record path and monitor at the same time?
Yes! The crosspoint router doesn't make any assumptions about what is routed. The digital monitor switching works over the top of the crosspoint router, and doesn't effect the record routing.
Can I send a digital output to multiple machines at the same time?
Yes! Each digital output is fully isolated and buffered, so you can drive as many machines as you have outputs..
Why have you got multiway connectors instead of XLRs on the rear panels?
The rack hardware comes from our igloo range, and we use multiway connectors because of the large possible density of connections. With the C2, there are 32 possible connections required, which would have taken up 3U of rack space instead of the 1U of the C2.
Can I upgrade the C2 if I want to go to 5.1 in the future?
Yes! The modular nature of the igloo rack and cards, means that we can upgrade and expand your console at any point. You'll be offered a full refund on every part we can re-use in your new console configuration.