When preparing for a new album, guitarists really need a fast and reliable way to compare and reconfigure their many amplifiers and cabinets without the lengthy process of manually swapping cables. Accurate comparisons between the different combinations are near impossible and the time taken between setup changes interrupts workflow. Our design solution to this problem allows the guitarist and producer to sit in the control room sweet spot and remotely configure the amp collection in seconds; they can achieve in a morning what had often in the past taken up to two days or more.  Description  The DACS HeadLine allows you to connect 8 amplifiers and 4 speaker cabinets. From there, you can select any connected amplifier and route it to a speaker or, if desired, two speakers simultaneously.  The HeadLine automatically detects whether loudspeakers are connected and only allows you to select channels which have speakers connected.  The HeadLine is packaged as two 1U rack enclosures. The first unit houses the user interface for the guitarist or engineer and the second unit is a relay switching box that sits next to the amplifiers. The units connect with a standard RJ45 network cable for easy routing and cable management.  The digitally-controlled relay switching ensures amp loads are maintained and the guitar input is muted during switching. The illuminated switches on the user interface indicate clearly which amp and speaker(s) are selected. 

HeadLite 3+ four channel Headphone Amplifier with +Power  Headphones are increasingly important for many aspects of audio production. The quality of headphone design and manufacture is higher now than it has ever been, and new technologies are producing headphones requiring significantly more power than traditional designs. Ensuring the very best performance from these headphones requires them to be driven by a dedicated headphone amplifier; +Power ensures that even these power-hungry beasts can be driven to their limit clearly and cleanly. ‘Making do’ with the headphone socket from the mix board or DAW doesn’t really ‘do’ at all.  Especially when there is more than one set of ears which need to listen in.  Clarity and Sound Quality  Whatever the headphone task the quality of the end-product begins with what the artist hears. Accurate, clear and detailed reproduction of the whole audible frequency range is essential; any shortcomings will inevitably affect both the overdub and the overview. HeadLite 3+ maintains the HeadLite series’ worldwide reputation for Clarity and detail.  Optimum Drive  The metering on the four busses that feed the amplifiers allows you to set the input levels to optimum, making sure the input to the amplifier gives the best output to headphones.  +Power  +Power is an analogue plug-in module that provides all the ultra-clean drive the most power-hungry headphones need. Fitted as standard in Channel 1, +Power can be added to the other channels either at the time of ordering or retrofitted later.  Power and drive  Amplifier power is not just about level (sound pressure level) it is about clean level (sonically pure level). A cheap headphone amplifier when pushed beyond its narrow limits can begin to distort before your headphones or your ears. This not only compromises the sound, but it can also damage your hearing. A headphone amp which has enough power should be `cruising’ for the whole of its useable range, the output signal always as clean as the technical specifications indicate it should be.  The power of the output on the standard channels is more than sufficient to drive virtually any headphone of any impedance clean and loud. +Power provides drive to spare for taking low-impedance high-power headphones to the peak of their performance. It will also allow the driving of multiple higher impedance phones.   Flexibility  In a studio you might use different headphones for different listeners providing different material. A good headphone amplifier will provide multiple outputs with individual amplifiers, each able to drive any impedance of headphone with selected inputs.  In the HeadLite 3+ this is provided by four bussed inputs selectable in combination - inputs A, B, C and D; for L and R respectively in the headphones, select AB, AA, BB, CD, CC or DD - on each of the four stereo output amplifiers.   Design  HeadLite 3+, like all our products, was designed with feedback from working engineers and musicians feeding our industrious boffins with ideas. The amplifier produces very low distortion and has an extended and flat frequency range; it scores top marks in Clarity and Sound Quality, Power and Drive, and Flexibility. As one user said of the original HeadLite “It’s ideal.”  Technical  Outputs for each channel appear on both the front and rear of the unit and can drive long audio lines to remote headphone outlets such as in vocal booths or over-dub rooms. Users can select from the four inputs (A, B, C and D) to hear A and B, or C and D as stereo, and A, B, C or D as mono. This means you can send two different stereo submixes to the HeadLite 3+ from the mixer or your DAW, or 4 mono mixes or a combination.  HeadLite 3+ offers excellent signal to noise ratio, low cross talk, bomb proof input stages, very low distortion and a bass response that is flat well under 20Hz. The unit’s frequency response (-0.5dB at 3hz to 35kHz) is within 0.1dB over the 22Hz to 22kHz band; because of the design of the amplifier’s output stage, its high frequency response does not suffer significantly even down very long lines.  HeadLite 3+ delivers all a recording professional needs in a rugged and reliable package that our service department can confirm will last for decades.   

Drive Topology Listening tests with a big mix of headphones confirm DACS’ Pure Class A topology excels for all types of headphones and listening levels. To run in Class A the Purity Headphone Amplifier and Purity BDZ© Power Supply generate a lot of heat. The case and inaudible ultra-quiet Noctua fan provide plenty of airflow to keep the temperature stable whatever the load. Differential Input DACS’ balanced input uses an instrumentation format, with hand trimmed CMRR to give the most accurate interference free signal. Differential Output Then we looked at ‘balanced’ headphones. The Purity Headphone Amplifier provides remarkably low cross talk between the two independent amplifier channels; using balanced output connections, that channel independence is maintained without compromise from the Purity BDZ© Power Supply all the way to the ears. Common Mode Rejection Ratio, a measure of the circuits ability to reject interference through its super steady Zero Ohm output impedance and a star earth scheme Purity Power Supply The new Purity BDZ© Power Supply uses a super stable, super low noise op-amp-based design, with Zero Ohm output impedance. When driven hard headphones produce back EMF, ie current flowing back towards the voltage regulator causing instability. In conventional PSU designs, this back EMF significantly reduces the PSU’s performance, with the amplifier losing control of the headphones, and generating distortion. DACS’ unique Purity BDZ© Power Supply design sinks that current away ensuring zero Ohm impedance and total output voltage stability, whatever is happening at the headphones. The Listening Experience You hear everything. Every spatial nuance, every timbral detail, every element of the musical spectrum, every fine adjustment. Poor mixes will be revealed, but great mixes will stand out in all their glory. Your headphones will give you more than you thought they could. Enjoy.