04/03: My Benchmark DAC1 PRE Best Settings
I have been researching for more than a month for a good digital to analog converter (DAC) to interface with my audio streaming player. This DAC will be the main decoder for my audio system which includes many components. After hours of reading reviews on different DACs I decided to go with the Benchmark DAC1 PRE.
The main deciding factors were price vs performance and a comprehensive feature set in the DAC1 Pre. In addition to the digital to analog conversion I was looking for at least one analog input for my home theater front speakers coming from my Rotel RSP-1066.
As a background I have a hybrid system where I separated my two channel audio system from the 5.1 home theater system. When I am listening to two channel music the Rotel RSP-1066 is off. When I am watching a movie the Rotel receiver is on including the front 2 channel speakers.
To make the story short the Benchmark DAC1 Pre had all that I needed plus extra features such as a headphone amplifier and a USB input.
System Configuration
Benchmark DAC1 PRE (Digital to analog conversion)
-Inputs
Logitech Squeezebox Touch (Audio Streaming) connected to DAC1 digital coax input.
Bravo D1 DVD player (CD player transport) connected to DAC1 toslink input.
Rotel RSP 1066 (Home theater front Channels) connected to DAC1 analog input.
-Output
Rotel RB-1090 connected to DAC1 XLR balanced output.
Tannoy D700 front channel speakers
Ground Noise Problem
Any audio multi-components setup faces the ground loop hum nightmare. This is no different with my setup when connecting the Rotel Receiver to the DAC1. My Tannoy speakers were producing a very audible buzz from 10 feet away. A search for a ground loop isolator ended up with a trip to Radio Shack (The Source in Canada) and an rca ground loop isolator was put in place. Since the audio signal coming from the Rotel receiver is just for home theater and not for serious music listening, the rca ground loop isolator was good enough for my setup.
Best DAC1 PRE XLR Gain Settings
The DAC1 comes with -20 db attenuator factory settings. At the default setting the DAC1 PRE did not exhibit a full dynamic range, at least not in my system. Somehow the music did not have a full body and I had an urge to turn the volume all the way up. I opened the DAC1 PRE and changed the Gain to 0db or neutral. The impact of this change is the high voltage output to my amp and the volume control is more restricted to a maximum of 12 oclock without having to blow my speakers or suffer a hearing loss. The sonic impact was much more noticeable and the DAC1 completely disappeared from my system. The only thing left noticeable was the shiny blue light. These settings were the ideal in my configuration, which might not be true to every system. The idea is to try different settings and find the best one for a given system.
Source comparison
Another test that passed to my ears was the switching between the squeezebox and the cheap Bravo D1 player used as transport. The sound reproduction was identical in every aspect when changing the input between those two sources.
Conclusion
For the price I paid for the DAC1 PRE I could not get a better deal. My system is sounding its best and is only limited by the source recording and my speakers accuracy in sound reproduction.