47 Labs Progression 4705 DAC with matching 4799 power dumpty.
This is an incredible unit.
Coaxial digital input. Unbalanced pair analog output.
The unit has some wear and looks used, but works and sounds flawlessly.
The Progression 4705 has slight nicks and scratches.
The 4799 power dumpty has 2 large scratches on one side, and a few nicks and scratches elsewhere.
These units are used in appearance, yet sonically perfect.
The DAC sounds as clean and wonderful as if new.
I am listing this far below the used market value due to the used appearance. I will consider reasonable offers.
I can also send more detailed pictures if need be.
Paypal add 4%
I will pay shipping in CONUS if asking price is met.
INFO FROM 47 Laboratory:
Non-Oversampling, No digital filter
No analog filter
World's shortest signal pass length --- 35m/m
World's smallest number of parts ------ 20 parts
Two piece chassis/casting made out of machined aluminum block
Input sampling frequency: 32kH, 44kH, 48kH (selected automatically)
Output voltage: 2.1V
Digital input: 1 Coaxial
Analog output: 1 pair, Unbalanced
Dimensions: Model 4705 60(w)x70(h)x162(d) m/m
Model 4799 130(diameter)x195(d) m/m
Non-Oversampling, Digital-filterless DAC
Non-Oversampling DAC concept was first proposed by Ryohei Kusunoki in late 1966. In recent interview, he states that "the issue is not either it is Non-Oversampling or Higher-rate-sampling, but the use of the digital filter can cause smearing in the time domain."
We can confirm this smearing effect on the sound caused by the use of digital filter rather easily through listening experiments. This leads us to believe that the current problem with CD is not the limitation of 16bit/44.1kHz format, but the use of the digital filter which is preventing us to experience the true possibilities and the limitations of 16bit/44.1kHz format. The sound of Progression is enough to prove this matter.
Passive I/V conversion
In Progression, I/V conversion is handled by a passive device instead of an active one. The result is a superb transient response without any over-shooting, and still maintains the output voltage of 2.1V.
World's shortest signal pass length and smallest number of parts
Our design priority, "Shorter the signal pass length, smaller the number of parts, better the sound" is most effective on digital components.
The signal pass length of Progression is 35m/m (including the length of parts), and the number of parts is 20. We are especially proud of achieving such a short signal pass length. We believe this defines the limit of short signal pass length on any production-model DAC.
2 piece machined aluminum-block chassis/casing
Chassis/casing of Progression is machined out of 2 pieces of solid aluminum block. The thick aluminum chassis/casing prevents the dispersion of digital noise and the use of only three screws in construction reduces the amount of stress on the chassis dramatically.
These construction qualities all contribute to the quick transient response, totally stable imaging and the flat energy balance of the sound.
The curved design of the top and bottom casing is no gimmick either. It holds a function as spike feet to release the vibrations smoothly and stabilize itself without any insulators underneath.