@brian27b
I have the 205 and Halo A51 in the configuration you speak of, Brian. Its been a while since you began this thread, so I hope input is still of use to you. Having read the other responses, I don’t see this info out here yet, and some of what I have to offer is directly contrary to what others have replied with.
- Contrary to what one responder posted, Paul McGowan, owner of the legendary PS Audio, has maintained thru his career of auditioning, testing, designing, building & selling hi-end audiophile equipment, that a Pre-Amp diminishes the sound quality of your system over a source direct to amp, unless 1 of two things are occurring: (1) A very hi end and expensive pre-amp of great design is being used, likely Tubed, or (2) it is improving the sound to the way you prefer your sound to be, but in fact, it is messing with the signal purity to do so, and therefore not better,,,its actually worse,,,its just better for you. Thus the expression, "get out of the way".... the most accurate sound of the source recording is on the source disc or digital media/usb/etc, and is diminished each time it goes through another piece of electronics. Now,,why would a guy (Paul McGowan) that designs, builds, and sells hi end audio equipment and pre-amplifiers over the $10k mark, openly throughout his life damage potential sales, by publicly telling others that they are diminishing the true quality of the sound by using a pre-amp 99+% of the time? In my own comparisons I have come to agree with Mr McGowan.
- You can hook up your Sony with the Oppo in one of two ways:
- by putting its HDMI out to the OPPO HDMI in, or any other of the digital out to digital in you like. If you believe that would be a downgrade of your Sony's digital sound processing, then there is option 2, below. I currently feed a Sony DVP-995V 400 disc player into my Oppo with HDMI, letting the Oppo do the decoding of the SACDs, CDs and DVD movies the Sony 400 disc player is spinning.
- you can either install an RCA input switch (I don't recommend, as it will be made of junk inside for the audio switching connections), or, at the amp, insert a set of dual RCA inputs, into each of the amps single RCA inputs. In this scenario, while the Halo amps should be fine if you accidentally had both sources go at the same time, as the total voltage would still be well below the 9.6 max volt input rating of the Halo. But, it still probably wouldn't be the wisest thing to have both sources accidentally go at the same time.
- The variable output of the 205 is NOT for headphone only, as one responder posted. Using it does not turn the gain up with the 1, very small, toroidal transformer the Oppo possesses, or headphone amp. When it is set at 100, that also happens to be the normal "fixed" playback volume setting of the Oppo. When you put it to 80, or 32, or whatever, all you are doing is stepping down the gain that it is normally providing to an amp or preamp if you were not in the variable output setting.
- The NAD is a GREAT Amp. I also compared it to the Halo A-51. Not going to get into all the details of my feelings, as you've probably done this at this point, and made your decisions based on your own preferences/needs or budget. But I did come to believe the A-51 was superior in more ways than the NAD was superior. I have since that time, added JC-1s for the front, and made the A-51 my surround only.
- The Halo A-_1 line has varying voltage input adaptability built into it. Most audiophile amps prefer higher voltage and want 4.8-9.6 dvolts to sound their best. The minimum input voltage they advertise or publish in the users manual is the minimum they are rated to accept without overstraining the amp, but they all prefer and operate better with more. A-51, A-21, etc, while still in the boat of performing best with higher voltage input up to 9.6V, is designed to adapt itself to incoming voltage and voltage changes, to maintain its quality sound balance as close to one point, in a way other amps do not.
I do find that while the A-51 is a lightning fast amp, that the rise-time of its sound curve could be better. Combined with the lightning fast audio info provided by the 205, it can, on poor recordings, sound too tinnie. Your speakers will determine if this is the case. But if you find it to be so, the resolution I created by accident, was to run a direct power feed to the audio in my home. The A-51 Needs unfettered feed power to perform right. Prior to doing that, I adjusted with cabling, which also worked well, but made me miss the step up incredible resolution that was present on everything but the poor recordings.
Hope you, or others, find some use in this & Happy Listening!
