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Yes Virginia, there are differences in CD players
We know. If you're reading this there's a good chance that
you're familiar with better quality audio components. But some
people who're reading this may not be, so please bear with us
while we cover some basics.
There are those who'll tell you that all CD player sound the same.
And certainly most CD players are at least "good". Yet, the
technology of reproducing digital source materials is fairly
complex, and there are differences in the implementation of that
technology. Yes, the information is stored as digital bits on the
CD and therefore doesn't change over time, or with repeated
copies. But the way it's read and decoded into the analog domain
has an impact on the final sound. And during that decoding process
if the error correction's needed (because of difficulty reading
the disc or poor "tracking" ability, or …) it can effect the
final sound. After the potential for sonic change during the
digital decoding of the CD information, there's the analog audio
output stages, which also have an impact on sound quality.
So are there sound differences between players? No question. Can
they at times be subtle? Absolutely. Is it worth buying a better
machine for better performance? Well, if you really enjoy
listening to music, and you're a critical listener, with a high
quality sound system, there's no doubt that it's worth it. Now,
let us tell you why the GCD-750 is among the top players you
should consider.
The differences are in the details
The GCD-750 is essentially a combination of Adcom's highly regarded digital processing circuitry, developed for our well reviewed stand alone D to A converters, and an advanced, high quality single play CD transport system. The result is a CD player that delivers the superior sound quality of separate CD components at an affordable price, in one attractive, easy to operate unit.
GCD-750 technical particulars (for those who aren't particularly technical)
The GCD-750 reads digital data from the CDs with a three beam laser assembly (a three beam design uses one beam to read the information, and two side beams to maintain tracking accuracy) which in turn is part of a massive and rugged transport assembly. The data (still in the digital domain) is fed into a Pacific Microsonics PMD-100 oversampling digital filter and HDCD decoder. HDCD is a relatively new process invented and patented by Pacific Microsonics. It's being used in the recording of certain CDs to enhance detail and clarity. When an HDCD disc is played back through an appropriately equipped machine it results in excellent sound and imaging. This advanced device is excellent at its job, even when it's used for standard discs. After the PMD-100 does its job, the oversampled digital signal if fed to two differential pairs of Burr-Brown 20 Bit linear Digital to Analog (D/A) converters. These are very high quality circuits, noted throughout the high end audio community for their superb performance. Using these converters ensures that even the most subtle musical nuance is reproduced cleanly and accurately.
Out of Digital, into Analog
After the signal has been converted to its analog form it must be amplified and sent on its way to your preamp. And what better send off than Adcom's famous Class A (the most highly regarded kind of amplifier circuit design) output stage. This is a discrete, high current, differential output section using reference grade MosFet transistors. In fact, hand selected, high quality components are incorporated throughout the output section to further guarantee the best sound and imaging possible. Note too that we've used this basic circuit configuration throughout this new series of components, and hundreds of hours of critical listening have confirmed its superior performance.
The all critical power supply
The GCD-750 is powered internally by another Adcom hallmark, an exceptionally large and capable power supply. Twin custom wound high current transformers, one for each channel, feed the GCD-750's digital and analog stages independently, through separate secondary windings. High current voltage regulators and "over specified" filter capacitors complete the power supply design, ensuring all the power necessary to reproduce the most demanding and dynamic musical passages.
Other important features
The GCD-750 is the culmination of Adcom's extensive high end audio experience and a major engineering project undertaken for this series. When you listen to it you'll surely understand what we mean when we say "Your ears will thank you".
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To help the GCD-700 achieve the highest quality sound reproduction, ADCOM's engineering staff chose to use the latest Burr Brown 20-bit ladder-type D/A converters. The same ones as used in the GDA-700. Rob Ain, ADCOM's Vice President of Marketing was particularly pleased with the results. The new player sounds exceptional and surprisingly close to the stand alone digital-to-analog converters that it was based around.
The analog section features class-A biased, direct-coupled, proprietary operational amplifiers as found in ADCOM's top of the line GFP-565 Preamplifier. These help the new changer to achieve extremely low levels of noise and distortion while offering a level of musicality typically reserved for much more expensive staid alone transport and D/A converter combinations. Frequency response is flat from 20Hz to 20kHz and phase differences between channels are typically less than 0.1 degree throughout the audible frequency range.
The power supply circuit for the GCD-700 utilizes two transformers, one for the analog section and the second for the digital section. Both are housed on separate circuit board assemblies to eliminate the possibility of EMI or RF interference from contaminating the critical analog stage while supplying adequate current for both stages. Further enhancing the power supply's capability is more than 10,000 uF of filter capacitance and multiple stages of regulation to generate dean DC power supplies for the various stages of circuitry.
The GCD-700 features two sets of RCA coaxial outputs, one fixed and one variable allowing maximum flexibility. In addition, it also provides a coaxial digital output for connection to an outboard D/A converter if so desired. All RCA jacks are gold plated for maximum conductivity and resistance to corrosion. Also included on the rear panel is an eight pin DIN connector allowing full remote accessibility and system integration using our GFB-800II Music Control Center.
As with all ADCOM products the front panel is a custom extruded and anodized aluminum assembly for maximum durability. Buttons and cosmetics have been updated to complement our latest generation of products.
For added convenience the changer comes supplied with a full featured 34 key remote including volume control functions for those who choose to use the variable output. Furthermore, operational features includes full programmability, digital polarity selection, random mode, and play/exchange capability. The last feature allows the operator to change the four remaining discs while the fifth one remains playing.
ADCOM, long prominent in the design, manufacture, and marketing of high performance, high value audio components is based in East Brunswick, NJ.
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Continuing on in the tradition of the widely accepted and industry recognized GDA-600 D/A Converter, ADCOM has recently unveiled its new GDA-700 D/A Converter. The GDA-700 will supplement the lineup of digital offerings that has been led by the highly successful GDA-600, itself a leader in offering unprecedented performance at an affordable price.
As expected, the GDA-700 drew a tremendous amount of positive response from both dealers and industry insiders. Rob Ain, ADCOM's Vice President of Marketing expects the GDA-700 to set new performance and value standards in the under $2000.00 DAC category. "Even though I knew the GDA-700 was destined to sound good I was amazed at the openness and musicality of this unit, especially when it was decoding an HDCD encoded disc. The results were nothing short of amazing".
The GDA-700 features two RCA coaxial inputs, one Toslink® optical input and one AES/EBU on an XLR connector. All RCA jacks and XLR connectors are gold plated for maximum conductivity and resistance to corrosion.
The input receiver is the highly regarded UltraAnalog® AES21 which decodes the digital audio signal while rejecting incoming jitter. The decoded digital audio signal is then applied to the new High Definition Compatible (HDCD®) process decoder from Pacific Microsonics.
Once the digital audio signal is received, decoded and filtered, it is applied to a pair of Burr Brown 20 bit ladder-type D/A converters which convert the digital signals to analog. The output stage features class-A biased, direct-coupled, proprietary op amps which achieve extremely low levels of noise and distortion as found in ADCOM's top-of the line GFP-565 Preamplifier. The GDA-700 also offers both balanced XLR and unbalanced RCA jacks for utmost flexibility when connecting the unit to your favorite preamplifier. Again, as with the input jacks, all XLR and RCA output jacks are gold plated to ensure maximum signal transfer.
The power supply circuit for the GDA-700 is contained on a separate circuit board assembly which utilizes two independent transformers including a low noise toroidal for the analog circuitry. More than 13,000 uF of filter capacitance and multiple stages of regulation generate clean DC power supplies for the various circuit stages. RFI and EMI filtering is handled by an integral AC filter/IEC inlet with a detachable three wire AC cord.
The anodized aluminum front panel includes a power switch, an input selector, a control for digital domain phase inversion and a row of LED indicators that display the digital frequency of the incoming signal. Also included is an HDCD indicator that lights whenever the HDCD decoding process is active.
The GDA-700 will carry a suggested retail price of $1000.00 and can be found at ADCOM dealers nationwide.
ADCOM, long prominent in the design, manufacture, and marketing of high performance, high value audio components is based in East Brunswick, NJ.