Crown Distinction Series DL-2 Controller
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Distinction Stereo Controller Model DL-2
Precision sound reproduction is the only reason to buy a Crown Distinction DL-2 Controller. The DL-2 is a common-sense design; a preamplifier that is uncompromisingly engineered to do nothing to the sound – unless you want "It to. We've been working a long time at Crown to perfect the pre-amplifier. We think the DL-2 is every close to that ideal.
Designed for sonic excellence
Signal-to-noise ratio better than 97 dB. Digital level control for perfect tracking accuracy over 63.5dB in .5dB steps. Frequency response ±0.1dB, 10 Hz to 50KHz, all controls set flat. You hear everything your signal source says to the DL-2, and nothing more. Harmonic distortion, intermodulation distortion and transient distortion are simply not audible.
Designed for flexibility
Because completely accurate reproduction of the input may include input material you would rather not hear, circuit modules are built into the DL-2 system that can be switched into – or completely out of – the signal path for precision shaping of the output. The DL-2 includes
loudness contour controls that allow you to select the compensation curve you want; tone controls that come close to forming a complete equalizer; stereo imaging with mixing functions. All controls are stepped, precise and exactly resettable.
The DL-2 may offer more than most people need for today's audio systems. It is built for tomorrow. In the DL-2, Crown offers a unit built with the most advanced technology – designed by and for the computer.
Designed by computer
Computer analysis of circuit design has for some time been a major tool available to Crown engineers. Time and again, the computer's findings have been verified by our listening tests. Crown engineers are now able to analyze – and
consider carefully – many more design possibilities through computer predition of the sonic behavior of each ci concept. The sonic excellence of the DL-2 is in large measure due to this procedure.
Designed for the computer
The DL-2 is the first audio component designed to interface with computercontrolled systems. Source selection, level controls, on/off and muting can be remotely controlled, or they can be computer controlled, at home or in the music hall. The DL-2 is the controller needed for tomorrow's audio systems, and it's available now.
© Crown International 1978
Ten Sound Reasons Why the DL-2 May Be
Besides providing an unmatched quality of sound reproduction, the DL-2 is also the most flexible control center available at any price. It allows the user to include in the audio signal path only those functions needed, when needed. Discussed below are some of the ways you can use the DL-2 to obtain the finest reproduced sound.
1. Mixing with source selection
Touch-button controlled reed relays provide input control of eight signal sources (plus power on/off and signal muter). In normal operation, selecting one source will automatically cancel any other input in memory. Several inputs can, however, be activated simultaneously to combine signals from two or more sources, depending on source impedance.
2. Accurately maintain level difference
Touch-button controlled reed relays provide 63.5dB level range for each channel in precise .5dB steps. Once you establish the desired level difference between channels, the center touch buttons will raise or lower sound levels on both channels and accurately maintain the selected level difference.
3. Select the desired loudness compensation curve
ISO curves in precision 5 phon steps from 100 to 55 phons are built into the DL-2. You select the precise compensation needed for your listening requirements, independent of level control.
4. Precision tone control
Three level-control switches per channel, with associated center-point adjustments, permit boost-or-cut (±15dB) for high, mid-range, and low frequency bands, for exact adjustment of spectral balance to compensate for environmental or source deficiencies.
5. Select your own external processor
Graphic equalization, Dolby, dBX, time delay, expander, or other special-purpose signal processors can be included in the DL-2 system as you desire. Rear panel connections permit hookup of any two. Front panel pushbuttons enable you to switch them in or out of the audio signal path. In addition, either processor (or both) can be switched just ahead of tape output. For re-recording, this allows the user to clean-up material that may be distorted, scratched or badly recorded. You can engineer better sound.
6. Precision stereo imaging and mixing
Six stepped attenuators provide unity gain at full range. "A" and "B" are selected stereo inputs. "L" and "R" are outputs. "X" and "Y" are additional stereo inputs. with separate rear panel connectors. With all six controls set at infinity no sound results, as all channels are fully attenuated. With (A→L, B→R) at full range, the system produces a full stereo image. If (A → R, B → L) only is set at full range, the DL-2 is in full reverse stereo. If all four of these controls are set at the same value, the DL-2 will be in mono. The stereo image of your system can be precisely adjusted to suit the performance. (X→L, Y→R) controls provide mix/fade capability for another signal source, or they can be used for a most unusual sound-shaping flexibility, acting as a built-in "mini-mixer.
the Best Control Center You Will Ever Own.
The Crown DL-2 Distinction Controller system is unique in the quality of its sound reproduction capability, and will not be equalled in flexibility and long-term reliability for some time to come. If you are sincerely interested in faithful sound reproduction, we urac you to listen – carefully – to a DL-2 controlled system. Your Crown dealer will be happy to answer any question you may have about the DL-2 system, and what it can mean for your own enjoyment.
7. Three machine tape copy in any combination
Simply turn a switch on the DL-2 front panel to set up copying from one of three tape machines to any other one or two. In addition, another tape recorder can be plugged into front panel jacks, and controlled by the T3 selector touchbutton. This copying flexibility is only available on the Crown DL-2 system.
8. Perfect tracking on multi-channel control
The DL-2 system can be expanded to 4, 6, 8 or more channels by slaving additional DL-2 units to the original. Rear panel connectors provide the necessary logic signals. Level control and input selection of all channels can be controlled from one panel with perfect accuracy.
9. Remote control
Source selection, level control, on/off and muting can be controlled by a remote wireless control system, available in 1979.
10. Select roll-off points for high/low filters
The DL-2 allows the user to select one of four roll-off frequencies on the high or low end. Gain is down 3dB at the selected frequency, with 18dB per octave roll-off. In addition, either or both filters can be removed completely from the signal path for a flat system response curve.
A Common Sense System Approach to Preamplification and Control
There are three major sources of output noise in conventional pre-amplifiers. One is RF interference, picked up principally by low-level, high impedance cable between turntable and preamplifier. A second source is AC line noise, picked up by signal path components in close proximity to AC power lines and transformers. The third is compromise in circuit design and component selection so often found in units designed to meet a desired price range, rather than a desired level of performance.
The DL-2 design solves each of these problems. The answers reflect the elegance of thorough, painstaking engineering, and the use of the most recent audio technology.
The DL-2 phono pre-amp is a separate, small, steel-encased unit designed for mounting as close to the turntable as you can get it. (One phono pre-amp is used for each turntable.) Turntable-to-phono pre-amp cabling is dressed as short as possible. The pre-amplified signal is then conducted to the DL-2 switching unit at the level of a standard input signal,
which neatly solves a major part of our first problem. RFI levels drop dramatically. The DL-2 phono pre-amp includes a sonically transparent toroidal inductor filter circuit to remove any remaining RFI noise. In addition, high-frequency response is no longer affected by excessive capacitance
in long, low-level cables. As an additional benefit, hook-up of the system is more flexible, since the phono pre-amp output can now be plugged into any input connector on the DL-2 switching module. If needed, you can control the output from eight turntables.
To solve the problem of AC line noise, the DL-2 system has a separate power supply designed for rack or Crown cabinet mounting. This module contains all AC lines, and supplies DC voltage only to the switching and phono pre-amp modules. In addition, the DL-2 power
transformer is actually two transformers, housed in a common case, and oriented with equal and opposite fields to minimize stray fields. All AC lines are thus removed from the signal processing areas of the DL-2, further enhancing the sonic excellence of the unit.
The power module contains nine 120volt AC outlets (seven switched, two unswitched) and delivers up to 20 amps (enough to drive four Crown SA-2 amplifiers).
To provide a complete list of the nocompromise decisions made by Crown engineers in solving the third problem of output noise is simply impossible in this short review. Some of the more important of these circuit decisions which contribute to your continued enjoyment of the DL-2's sonic excellence are:
Optimized front-end bias point in the phone pre-amp module results in a noise level less than the thermal noise inherent in the best of caruidges.
- Digital, precision tracking level control eliminates image shift frequently found in rotary continuous or stepped controls.
- Switch selectable frequency response (flat or RIAA) in phono pre-amp module.
- Level control is accomplished by removing excess gain rather than by attenuating the signal, to achieve the best signal-to-noise ratio throughout the control range.
- Low impedance design used throughout the DL-2 switching module to reduce noise.
- Overload indicators monitor several key points in the DL-2 signal path, not just the output. Clip point of pre-amplifier can be accurately monitored.
- Three-pole active Butterworth filters provide accurate 18dB/octave rolloff, with adjustable high and low frequency turnover points.
Unique op amps designed specifically for use in audio systems.
- High gain bandwidth FET input op amp as output stage of the phono pre-amp module provides a high slew rate for excellent transient response.
- Input impedance in the phono preamp is switch-selectable to properly match the output impedance of most cartridges, thereby optimizing cartridge performance.
- Touch-button controlled, hermetically sealed reed relays for input switching and level control. Control switch transients are kept out of the signal path. Relay performance cannot be degraded by air-borne contaminants.
- Muting switch is automatically activated by "power on." Speakers and amplifiers are protected from turnon transients.
- 13-position, gold-plated stepped linear switches in the tone control module provide precise, resettable, reliable boost-or-cut control.
The DL-2 system, with its separate phono pre-amp, separate power supply, and no-compromise circuit design, is the expression of common-sense engineering concepts combined with the most advanced audio design techniques, as only Crown has done it.
SWITCHING MODULE
Frequency Response (10K load): ±0.1dB, 10Hz—50KHz; ±0.5dB, 1Hz—100KHz.
Phase Response (10K load): Within ±8°, 20Hz-20KHz.
| Hum 8 | Noise (dB belo | w rated |
|---|---|---|
| outp | ut, inputs shorte | d, |
| 20H | z—20KHz): | |
| Unweighted | A weighted | |
| Max | dain 97 | 101 |
Max. gain 57 107 Unity gain 103 107 Min. gain 110 118 Intermodulation Distortion (10K Ioad, SMPTE analyzer):
>.0003% @ or below 10v out Total Harmonic Distortion (10K load): 2.5v rated 10v output 1KHz >.0003% >.0006% 20Hz .0003% >.0006%
20Hz— 20KHz >.0008% >.0025% Noise Transfer IM Distortion (10K
load): >.002% @ 2.5v peak equiv. level; >.001% @ 10v peak equiv. level. Test signal 10KHz-26KHz white noise (crest factor 3.9); distortion products measured below 10KHz; NTIM testing is highly sensitive to audible products of high frequency distortion mechanisms such as S.I.D. (T.I.M.).
- Inputs: Eight dual-channel high level, touch-button selectable with LED indicators. Two dualchannel inputs for external signal processors. One dual-channel mixable input (crossfeed).
- Input Gain & Impedance: 20dB ±0.2dB, 100K ohm (impedance constant unless inputs are paralleled).
Outputs: 11v RMS max. before overload; 2.5v rated @ 50 ohm output impedance. 22v RMS max on balanced outputs; 5.0v rated @ 100 ohm output impedance. One dual-channel buffered output.
Distinction
Stereo Controller Model DL-2
SPECIFICATIONS
Each DL-2 system is fully calibrated and inspected when it leaves the factory. Crown warrants that every DL-2 produced will meet or exceed the specifications set forth here, and guarantees the owner that for a period of three years after original purchase, Crown will repair or replace any defective part at no cost to the owner. Included in this guarantee is the cost of round trip shipping of the unit from the owner's home to a designated Crown service center or to the factory. See your dealer for the complete text of the Crown full warranty.
Headphone Output:
Connector: Front-panel stereo 3-circuit 1/4" phone jack. Impedance: >10hm (>220 milliohms in series with >6 microhenries). Max Level: 17v RMS
Frequency Response: ±0.1dB, 10Hz—50KHz @ 17v RMS. Gain—Balance Controls:
Gain—Balance Controls: Digital touch-button controls (0.5dB increments, 129 positions, 63.5dB dynamic range) for active, seven section, precision switched, gain controllers. Individual control for each channel, or ganged control with fullrange tracking accuracy of ±0.2dB.
Gain—Balance Display: Sevensegment LED displays show gain in dB above minimum for each channel.
Loudness Compensation: Rotaryswitch selectable precision widerange ISO curves from 100 to 55 phons in 5 phon steps. Three-pole compensation.
Tone Control: Shelving bandpass type precision-stepped bass, mid and treble controls for ±15dB boost/cut. In/out switch cancels to true flat. Center frequency selectable: Bass 20, 40, 80Hz; Mid 400, 800, 1600Hz; Treble 5K, 10K, 20KHz.
Filters: Precision stepped adjustable roll-off filters, down 3dB at selected frequency with 18dB/ octave roll-off. Low filter adjustable to 20, 30, 50 or 100Hz. High filter adjustable to 4K, 7K, 12K or 20KHz. In/out switch cancels to true flat.
Tape Monitors & Copy: Three inputs (T1, T2, T3) include monitor functions for A-B taping. Tape-copy is switch-selectable to copy from master input bus or from any one recorder to any two others.
External Signal Processors: Separate rear panel dual-channel inputs and outputs. Switch selectable in or out of audio path. Switchable ahead of tape function.
Audio Imaging: Stepped 31position switched attenuators for precision adjustment (±0.2dB over 50dB range) of stereo image. Six controls on three axes adjust stereo, mono, reverse stereo and external second-
source mixing. Muting: Relays provide 5-7 secs. delay acturn-on.
Remote (Module available 1979): Remote control of input selection, power on/off, muting, gain and balance. Additional DL-2 systems are controllable from master for multi-channel operation with all specifications maintained for any combination of channels
Computer Interface: DL-2 logic designed for computer control, and all units include rear-panel computer connector.
Dimensions: 17x71/2x14in. (43.2x19.0x35.6cm), behind front panel. Front panel fits EIA 19" rack.
Weight: 20 lbs. (9Kgm).
Finish: Satinized aluminum front panel with charcoal Lexan inlay; other surfaces black anodized.
POWER SUPPLY
Power Requirement: >40 watts @ 120 VAC.
AC Outlets: Seven switched (three 20 amp, four 15 amp), two unswitched.
DC Outputs: ±28v @ 500mA; ±18v @ 500mA and +10v @ 2 amps.
Dimensions: 17x31/2x71/2in. (43.2x8.9x19.0cm). Front panel fits EIA 19" rack.
Weight: 9lbs. (4.05Kgm). Finish: Satinized aluminum front
panel with black anodized chassis
PHONO MODULE A
Frequency Response (10K load): ±0.25dB of RIAA, 20Hz—20KHz (switch at RIAA). ±0.1dB, 10Hz— 30KHz (switch at flat).
Phase Response (10K load): Within ±5°, 20Hz—20KHz (RIAA); +2°, -12°, 20Hz— 20KHz (flat).
Hum & Noise (dB below 10mv input, inputs shorted, 20Hz— 20KHz) Unweighted A weighted
RIAA 88 94 Flat 84 89
Intermodulation Distortion (10K load, SMPTE analyzer): >.0005% @ 2.5v out (switch in flat).
Total Harmonic Distortion (10K load): >.002%, 20Hz—20KHz @ 2.5v out.
Noise Transfer Distortion (10K load): >.0004% @ 2.5v peak equiv. level.
Input Gain: Adjustable from 30 to 50dB, 2.5v @ 1KHz for rated output @ max. gain.
Input Impedance: 47 or 100K ohms, switch selectable. Parallel capacitance at input jack less than 5pf.
Input Overload: 33—330mv @ 1KHz depending on gain. 100mv @ 40dB gain.
Output Impedance and Voltage: 600ohms with max. 11v RMS, 20Hz—20KHz, 10K load.
Dimensions: 13/8x31/2x65/8in. (3.5x8.9x16.8cm).
Weight: 12 oz. (337gm)
Finish: Black anodized steel. PHONO MODULE B (optional module available late 1978): Moving-coil cartridge phono preamp.
1718 W. Mishawaka Road, Elkhart, Indiana 46514
American innovation and technology...since 1951.
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