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Aragon produced several source components. This guide is intended to familiarize you with the Aragon radio tuner, digital-to-analog converters, and phono preamp. Aragon is the highest-quality division of Mondial Design. Other Mondial Design divisions are Acurus (providing excellent quality at a lower price) and AMFI, a short-lived attempt to bring Asian product upmarket. Mondial Design was sold to Klipsch on or around 2000/2001, and all Aragon, Acurus, and Amfi product has been discontinued in the years since then. However, rumors of rumors persist that Aragon will be reborn...
Please note that I am indebted to Mike Kusiak for supplying me with quotable e-mails with corrections and additions to my other Aragon guides for preamps and home-theater processors and classic Aragon amps . A quote from him that is appropriate to material in this guide is in italics. All errors or omissions are MINE, not his. I would also like to thank Steve Donalson and Adam Gershon of Klipsch for answering my questions in the Klipsch Forums.
The Aragon radio tuner model 4T2
Aragon had a slick AM and FM stereo radio tuner called the 4T2. As was traditional for Aragon, it was intended to be a high-value device, that is, excellent quality, while selling for less than a person would expect to pay. There are 16 pre-sets for channel selection, along with buttons to control the tuning, "seek" feature, and distant station filter. All input connectors are gold-plated to resist corrosion, and the outputs are very high quality gold-plated Tiffany jacks. The circuit board is encased in a copper-lined shield, while the in-chassis power transformer itself is encased in a steel sub-chassis to protect the circuitry from stray magnetic fields. The incoming signal is further isolated by the Mondial Antenna Ground Isolation Circuit (MAGIC) which prevents the antenna--roof mounted or cable--from allowing interference into the tuner through the antenna ground connection. (The MAGIC circuitry was also available in stand-alone boxes including one useable as a "splitter" for cable TV/Radio signals.) Chassis design is by Robbii Wessen, who did all of the Mondial industial design work up to the point of the Klipsch takeover. It is similar to the 24K and Aurum preamps, using a horizontal V shape for the front face ("<") An interesting fact is that the clear panel on the front--made of plexiglass--was precicely cut to shape by a laser.
The 4T2 went on sale on or around 1989. October 1990 Audio magazine has a price of $599, this increases to $695 in the October '91 issue.
(Sorry, I have NO CONTROL over the size of the photos.)
Aragon 4T2 photos and price info graciously supplied by audio_maven, used with his permission.
The Aragon digital-to-analog converters D2A, D2A Mark II, and D2A2
The original D2A was designed in conjunction with famed Theta Digital Corporation. This Aragon digital-to-analog converter was designed as a 18-bit 8X oversampling converter for use with CD and DAT machines, it operated at 32, 44.1 and 48 kHz sample rates, with the correct rate selected automatically. Twin, premium Burr-Brown 18 bit DAC chips mated with a Texas Instruments filter chip. There were three inputs, using two coaxial and one Toslink connectors; and a single digital tape output via coaxial jack. Absolute phase could be reversed using the (connected by a wire, not cordless) remote control. The analog circuit board was said to be all-discrete (no IC chips) class "A" dual-mono board related to the phono circuit topology employed in the 24K preamp. The digital board was encased in a metal shield to prevent it's electromagnetic radiation from contaminating the signal on the analog circuit board. In fact, no digital information was permitted to reach the analog circuit boards. The power supply used was external, consisting of either the standard power supply or, at extra cost, the Isolated Power Supply (IPS, more on that later) either of which also worked with the Aragon preamps as well. All digital ICs as well as the entire digital circuit board are easily removeable to make upgrading the components as easy as possible.
The D2A is listed in the October 1990 Audio magazine as selling for $995
The D2A Mark II was based on the original D2A, but it included refinements (a more-refined reclocking circuit) to reduce jitter by a claimed 40%. Jitter was identified as a source of digital--and therefore analog--distortion. The analog circuitry gained an additional circuit board, a low-impedance output buffer stage. Upgrading a D2A to a D2A Mark II cost $295 as of the time the new Mark II was introduced. The October 1991 Audio magazine shows a price of $1595 for the D2A Mk II.
D2A; D2A MK II similar
Internal view of D2A showing digital (shielded) and analog circuit boards
The D2A2 is a complete re-think of the previous D2A and D2A Mark II. It used an internal power supply, the previous external supplies cannot be used. The D2A2 used the HDCD 8X oversampling filter which was suitable for large-size laser discs, CDs and HDCDs. The DAC chips used are Burr-Brown 20-bit monolithic units in dual configuration. As with the earlier units, the D2A2 would run at 32, 44.1 and 48 kHz sample rates, with switching of sample rates being automatic. Unlike the earlier units, there is no digital output jack and no switching of absolute polarity. Digital inputs are through 2 coaxial jacks, a Toslink optical jack, and one AES/EBU compatable jack. Turning the D2A2 on and off is done by turning the single knob on the front panel clockwise. Switching inputs is done by turning the same knob counterclockwise.
The D2A2 is listed in the October, 1998 issue of Audio magazine as having a list price of $999.
The Aragon phonograph preamp 47K
The name 47K, of course, is a pun based on the fact that many phono cartridges use a 47,000 ohm recommended load impedance, and 47 Thousand can be written as 47K. It also played into the numbering system of the Aragon preamps, 24K, 18K, and 28K. The 47K "pre-preamp" was responsible for accepting the output of your phonograph cartridge (perhaps less than one thousandth of a volt) and amplifying that signal to the point that an ordinary preamp or reciever could accept the voltage signal through it's "line level" inputs. In addition, it needed to equalize the frequency response of the signal generated by the cartridge to an industry standard called the Recording Industry Association of America (RIAA) curve. Because the amplification and equalization needs to be extremely precise, the 47K had no front-panel switches to corrode or get dirty, and there was no power switch because the unit was intended to be "on" all the time to maintain stable operating temperature. All switching was done inside the case, using a gold-to-gold shorting bar for the gain, and with epoxy-sealed resistors soldered to the circuit board, and gold-to-gold shorting bars to bring them into the circuit to adjust the impedance.
Like most of the Aragon preamps and digital converters, the 47K uses an external power supply which assures that only regulated DC enters the sensitive 47K chassis.
Consistency and quality was guaranteed by using only epoxy-sealed resistors, matched transistors, and 1% tolerance capacitors on a double-sided glass epoxy circuit board employing oxygen-free copper traces and plated through-holes.
The 47K is shown in the October, 1998 Audio magazine as having a list price of $595 with the standard power supply.
The IPS and other power supplies
All Aragon components that use an external power supply--most of the preamps, the D2A and D2A Mark II, and the 47K--can be powered by a standard outboard power supply, or an upgraded, more powerful supply called the IPS. One component (the Aurum preamplifier) was supplied with a still-more-powerful outboard supply called the Ingot.
"The Ingot power supply can only be used with the Aurum. Although both the IPS and the Ingot supply the same plus and minus 24VDC, the output plugs are different. The IPS has a 3 pin XLR, while the Ingot uses a 4 pin XLR. This was purposly done so that users would not accidentally plug the power supply cord into one of the Aurum's balanced outputs which also used a 3 pin XLR. If you change the plug, you can use an IPS with the Aurum, or an Ingot with the other Aragon preamps" [or other Aragon components that require an external power supply]. That also applies to the standard power supply: if you have the correct connector, it can be used on any of the external-supply components. The standard power supply uses the three-pin style connector.
The October 1998 Audio magazine shows that the price for an IPS power supply is $250, this is in the "notes" columm at the end of the 47K phono preamplifier description.
The "standard" power supply, showing the "plug in" for the wall socket as well as the XLR connector that attaches to the back of the preamp or D/A processor. My thanks to Dave's Retro Stereo Music and More for permission to use this photo.
If this guide has been helpful, please give me a "Yes" vote by clicking the button below. If you have suggestions for improvement, you can contact me through the "My Messages" feature of eBay, by clicking my user name above, then click on "Contact Member". Thanks, All.
Entire contents copyright (C) 2007, 2008 Camino3X2 Feel free to LINK to this guide in your auctions.
Please note that I am indebted to Mike Kusiak for supplying me with quotable e-mails with corrections and additions to my other Aragon guides for preamps and home-theater processors and classic Aragon amps . A quote from him that is appropriate to material in this guide is in italics. All errors or omissions are MINE, not his. I would also like to thank Steve Donalson and Adam Gershon of Klipsch for answering my questions in the Klipsch Forums.
The Aragon radio tuner model 4T2
Aragon had a slick AM and FM stereo radio tuner called the 4T2. As was traditional for Aragon, it was intended to be a high-value device, that is, excellent quality, while selling for less than a person would expect to pay. There are 16 pre-sets for channel selection, along with buttons to control the tuning, "seek" feature, and distant station filter. All input connectors are gold-plated to resist corrosion, and the outputs are very high quality gold-plated Tiffany jacks. The circuit board is encased in a copper-lined shield, while the in-chassis power transformer itself is encased in a steel sub-chassis to protect the circuitry from stray magnetic fields. The incoming signal is further isolated by the Mondial Antenna Ground Isolation Circuit (MAGIC) which prevents the antenna--roof mounted or cable--from allowing interference into the tuner through the antenna ground connection. (The MAGIC circuitry was also available in stand-alone boxes including one useable as a "splitter" for cable TV/Radio signals.) Chassis design is by Robbii Wessen, who did all of the Mondial industial design work up to the point of the Klipsch takeover. It is similar to the 24K and Aurum preamps, using a horizontal V shape for the front face ("<") An interesting fact is that the clear panel on the front--made of plexiglass--was precicely cut to shape by a laser.
The 4T2 went on sale on or around 1989. October 1990 Audio magazine has a price of $599, this increases to $695 in the October '91 issue.
(Sorry, I have NO CONTROL over the size of the photos.)
Aragon 4T2 photos and price info graciously supplied by audio_maven, used with his permission.
The Aragon digital-to-analog converters D2A, D2A Mark II, and D2A2
The original D2A was designed in conjunction with famed Theta Digital Corporation. This Aragon digital-to-analog converter was designed as a 18-bit 8X oversampling converter for use with CD and DAT machines, it operated at 32, 44.1 and 48 kHz sample rates, with the correct rate selected automatically. Twin, premium Burr-Brown 18 bit DAC chips mated with a Texas Instruments filter chip. There were three inputs, using two coaxial and one Toslink connectors; and a single digital tape output via coaxial jack. Absolute phase could be reversed using the (connected by a wire, not cordless) remote control. The analog circuit board was said to be all-discrete (no IC chips) class "A" dual-mono board related to the phono circuit topology employed in the 24K preamp. The digital board was encased in a metal shield to prevent it's electromagnetic radiation from contaminating the signal on the analog circuit board. In fact, no digital information was permitted to reach the analog circuit boards. The power supply used was external, consisting of either the standard power supply or, at extra cost, the Isolated Power Supply (IPS, more on that later) either of which also worked with the Aragon preamps as well. All digital ICs as well as the entire digital circuit board are easily removeable to make upgrading the components as easy as possible.
The D2A is listed in the October 1990 Audio magazine as selling for $995
The D2A Mark II was based on the original D2A, but it included refinements (a more-refined reclocking circuit) to reduce jitter by a claimed 40%. Jitter was identified as a source of digital--and therefore analog--distortion. The analog circuitry gained an additional circuit board, a low-impedance output buffer stage. Upgrading a D2A to a D2A Mark II cost $295 as of the time the new Mark II was introduced. The October 1991 Audio magazine shows a price of $1595 for the D2A Mk II.
D2A; D2A MK II similar
Internal view of D2A showing digital (shielded) and analog circuit boards
The D2A2 is a complete re-think of the previous D2A and D2A Mark II. It used an internal power supply, the previous external supplies cannot be used. The D2A2 used the HDCD 8X oversampling filter which was suitable for large-size laser discs, CDs and HDCDs. The DAC chips used are Burr-Brown 20-bit monolithic units in dual configuration. As with the earlier units, the D2A2 would run at 32, 44.1 and 48 kHz sample rates, with switching of sample rates being automatic. Unlike the earlier units, there is no digital output jack and no switching of absolute polarity. Digital inputs are through 2 coaxial jacks, a Toslink optical jack, and one AES/EBU compatable jack. Turning the D2A2 on and off is done by turning the single knob on the front panel clockwise. Switching inputs is done by turning the same knob counterclockwise.
The D2A2 is listed in the October, 1998 issue of Audio magazine as having a list price of $999.
The Aragon phonograph preamp 47K
The name 47K, of course, is a pun based on the fact that many phono cartridges use a 47,000 ohm recommended load impedance, and 47 Thousand can be written as 47K. It also played into the numbering system of the Aragon preamps, 24K, 18K, and 28K. The 47K "pre-preamp" was responsible for accepting the output of your phonograph cartridge (perhaps less than one thousandth of a volt) and amplifying that signal to the point that an ordinary preamp or reciever could accept the voltage signal through it's "line level" inputs. In addition, it needed to equalize the frequency response of the signal generated by the cartridge to an industry standard called the Recording Industry Association of America (RIAA) curve. Because the amplification and equalization needs to be extremely precise, the 47K had no front-panel switches to corrode or get dirty, and there was no power switch because the unit was intended to be "on" all the time to maintain stable operating temperature. All switching was done inside the case, using a gold-to-gold shorting bar for the gain, and with epoxy-sealed resistors soldered to the circuit board, and gold-to-gold shorting bars to bring them into the circuit to adjust the impedance.
Like most of the Aragon preamps and digital converters, the 47K uses an external power supply which assures that only regulated DC enters the sensitive 47K chassis.
Consistency and quality was guaranteed by using only epoxy-sealed resistors, matched transistors, and 1% tolerance capacitors on a double-sided glass epoxy circuit board employing oxygen-free copper traces and plated through-holes.
The 47K is shown in the October, 1998 Audio magazine as having a list price of $595 with the standard power supply.
The IPS and other power supplies
All Aragon components that use an external power supply--most of the preamps, the D2A and D2A Mark II, and the 47K--can be powered by a standard outboard power supply, or an upgraded, more powerful supply called the IPS. One component (the Aurum preamplifier) was supplied with a still-more-powerful outboard supply called the Ingot.
"The Ingot power supply can only be used with the Aurum. Although both the IPS and the Ingot supply the same plus and minus 24VDC, the output plugs are different. The IPS has a 3 pin XLR, while the Ingot uses a 4 pin XLR. This was purposly done so that users would not accidentally plug the power supply cord into one of the Aurum's balanced outputs which also used a 3 pin XLR. If you change the plug, you can use an IPS with the Aurum, or an Ingot with the other Aragon preamps" [or other Aragon components that require an external power supply]. That also applies to the standard power supply: if you have the correct connector, it can be used on any of the external-supply components. The standard power supply uses the three-pin style connector.
The October 1998 Audio magazine shows that the price for an IPS power supply is $250, this is in the "notes" columm at the end of the 47K phono preamplifier description.
The "standard" power supply, showing the "plug in" for the wall socket as well as the XLR connector that attaches to the back of the preamp or D/A processor. My thanks to Dave's Retro Stereo Music and More for permission to use this photo.
If this guide has been helpful, please give me a "Yes" vote by clicking the button below. If you have suggestions for improvement, you can contact me through the "My Messages" feature of eBay, by clicking my user name above, then click on "Contact Member". Thanks, All.
Entire contents copyright (C) 2007, 2008 Camino3X2 Feel free to LINK to this guide in your auctions.
Guide created: 10/10/06 (updated 08/17/08)
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