With the recent resurgence of CDs, and also the release of the Fiio DM15 R2R portable CD player, I thought I would revisit my Sony D-7 (also called D-50 MKII).
Because--the Sony D-7 has a Burr Brown PCM55HP R2R DAC inside. And it got me wondering, are there any other vintage portable CD players with an R2R DAC? Although there are many 16-bit vintage portable cd players, and I own a few, I wonder if this is the only production model ever made with a true R2R. I'm not necessarily implying R2R is the best DAC, but I am just curious for more information.
I cannot image that any other manufacture would have tried to cram this design into a portable CD player. Looking at the service manual, it has more components (transistors, chips, caps, etc) than most of my component CD players. The Sony D-7 is an engineering marvel of arranging all the parts required to pack a full component CD player into the space of 3 CD jewel cases. So, this tiny CD player has 3 double sided PCBs and a large DC-DC convertor to create a +5 -5V split rail system for the unit. These tiny electrolytic capacitors will be a pain to replace due to their unusually small physical space. There is not a single cubic millimeter of free space inside this unit. Which is also why it uses an external battery pack.
If you're curious about how it sounds there is a great modern re-review on hifinews:
www.hifinews.com
To my untrained ears, it sounds fantastic and the headphone output is just as powerful as a dedicated headphone amp. I actually have to use a headphone attenuator when I use this with my headphones because it is too loud.
Because--the Sony D-7 has a Burr Brown PCM55HP R2R DAC inside. And it got me wondering, are there any other vintage portable CD players with an R2R DAC? Although there are many 16-bit vintage portable cd players, and I own a few, I wonder if this is the only production model ever made with a true R2R. I'm not necessarily implying R2R is the best DAC, but I am just curious for more information.
I cannot image that any other manufacture would have tried to cram this design into a portable CD player. Looking at the service manual, it has more components (transistors, chips, caps, etc) than most of my component CD players. The Sony D-7 is an engineering marvel of arranging all the parts required to pack a full component CD player into the space of 3 CD jewel cases. So, this tiny CD player has 3 double sided PCBs and a large DC-DC convertor to create a +5 -5V split rail system for the unit. These tiny electrolytic capacitors will be a pain to replace due to their unusually small physical space. There is not a single cubic millimeter of free space inside this unit. Which is also why it uses an external battery pack.
If you're curious about how it sounds there is a great modern re-review on hifinews:
Sony Discman (D-50 MkII)
While first to market with a portable player, Sony soon found itself overtaken by rivals. Its answer was a now-iconic machine, driven by a belt. But how does it sound today? Sony's original D-50 'Compact Disc Compact Player', released in late 1984, was the first practical portable to reach...
www.hifinews.com
To my untrained ears, it sounds fantastic and the headphone output is just as powerful as a dedicated headphone amp. I actually have to use a headphone attenuator when I use this with my headphones because it is too loud.