I recently received my upgraded Isabellina HPA back from Vinnie, and on his advice added the Pro DAC option. As I highly value all of the knowledgeable advice that I have received here in the RWA Forum, I hope that I can add a useful perspective for those considering this option.
I have a headphones only system, comprised of the following:
MacBook Pro/Amarra>Toslink>Isabellina LFP-V into the following headphones:
- Shure SRH1840
- Audeze LCD-2 v.1
- AT-W3000ANV
I primarily use the matching AT-HA5000ANV amplifier for my AT headphones so have not referred to this setup with the Pro DAC.
The Pro DAC:
For your high Rez computer audio files it is a no brainer for well recorded music where you will immediately notice the difference. One example being Elton John's Captain Fantastic album in high Rez. It is simply stunning with the Pro DAC and the right headphones/speakers. Not so much so though with a number of other high rez recordings such as the LSO/Hatlink Beethoven symphony recordings offered by the B&W Society of Sound. I preferred some of the more well known redbook recordings to these. One very good LSO/Gergiev recording though is the Rachmaninoff Symphony No. 2, also offered by B&W.
As others have commented, personal sound preferences that have dictated the components you have selected for your sound system and in particular your speakers/headphones, will dictate how valuable an option this is to you - plus of course whether or not you already have a high Rez option in your system.
For Redbook, I love the High rez option with my Shure headphones where I am looking for layering, detail and clarity. I love the Pro DAC with these headphones, which to me are a combination of Sennheiser's HD-600 and the AKG 701 - but significantly better. For the LCD-2s, however, IMO, the NOS DAC is more musical and compliments their sound signature better with Redbook.
One thing the Pro DAC has taught me though, is that resolution is not everything! All of the qualities of the original NOS DAC stand out when you can just flip a switch to hear either one. An example for me is Glen Gould's recording of Bach's Well Tempered Clavier. Think of the piano being used as a giant harpsichord. I found the Pro DAC to be too percussive for me listening to the entire Book One in one sitting. The NOS DAC on the other hand rounds the notes out and smoothed out the sound which let me focus on the music.
One last musical example - Kiri Takanawa's CD Ave Maria. The Shures plus Pro DAC really bring out the layering of the music and improved clarity on this album, which is recorded in a cathedral creating a number of challenges. It becomes more 3D with the Pro DAC and changes this from what can sound like a very average/poor recording because of the sonic challenges presented as a result of recording in the cathedral, to something closer to being there Live.
As I hope you can tell, for my setup, the Pro DAC is a great addition to my system at a reasonable cost, and having both options in one box is a perfect solution for me.
Thanks Vinnie for making this an option on the Isabellina!
