What follows is my impression of the Duet Mod offered by Pat of Analog Research Technology. If you have any questions address them to Pat in this thread...AFAIK, the mod costs $500 including the power supply.
http://www.audiocircle.com/index.php?topic=61608.msg662968;topicseen#newMy main rig consists of a Marantz SA8250 SACD player with it digital out connected to a Musical Fidelity quad stack (DAC, tube buffer, power supply, headphone amp), Revelation Audio Labs Passage cords from MF power supply to DAC and tube buffer) using Audioquest cabling. Amplifier used is a PrimaLuna Dialogue One with KT66 tubes. Audioquest Diamondback interconnects were used with Reality Cables speaker wire. My speakers are ACI Sapphire XLs and the room is about 10X18 including an open kitchen at one end.
Playing CDs sounded great on this system when everything was dialed in. Decided to add a PC based system, and my choice was a Logitech Duet. I'd heard it bandied about repeatedly on several forums: Bits are bits...transports don't really matter...an upsampling DAC will attenuate any inherent jitter... the Duet receiver has low jitter anyway etc etc. Plugged in my Duet and ran an A/B comparison with my CD player playing the same CD. The Duet sucked in comparison...and by a large margin. The sound was harsh in comparison and imaging suffered on my system. Hmm, the much maligned switching power supply had to go! I replaced the power supply with one from Channel Island Audio. The harshness was gone, and the dimensionality returned some. It was a significant improvement, but the Marantz used as a transport was still better. My biggest quibble now was a lack of air and a slightly congested sound.
Enter the Duetta...OK, I'd read Pat's posts on his upcoming Duetta mods and scientifically they made sense to me. I'm a geneticist, so scientific thought is not an entirely alien concept to me. However, in this case, the proof would be in the pudding...or in the hearing, so I signed up to be on Pat's list. I have to admit, the paucity of reports on what the mod sounded like bothered me a bit. Pat steadfastly refuses to describe the changes, citing designer bias, and prefers to leave descriptions of the sound to his customers and listeners. When one of the original Duetta testers decided to go with Pat's new USB option and offered to sell his Duetta, I was all over it. It is important to keep in mind that the version I now own may not be the final version, since Pat has been continually refining the mod. Also the power supply I have is Version 3, which is what the original purchaser preferred.
So how does it sound??? As Billy Crystal would say "Mahvellous". What was instantly apparent was it seemed as if the sound was stretched towards both extremities; however, everything was still perfectly balanced. No longer was the sound congested. Others have commented on the 'air' and the sound 'emanating from a black background' and I heartily concur. Subtle details were revealed and the cymbals and triangles shimmered as they should. The bass gained gravitas and impact as well. Most importantly, there were significant improvements to the soundstage in my set-up. Everything was much better layered and cohesive. I dare say the Duetta + MF stack was better than the Marantz (a Stereophile class A component in its day) directly connected to the amp using Harmonic Technology TruthLink interconnects. Significant improvement was also seen in my less-revealing bedroom system: Logitech Duet, Cambridge Audio DACmagic, Marantz SR8400 receiver, Morel Octave 5.2 speakers, though the magnitude of improvement was a little less dramatic. One quick note: I have not checked to see if Internet Radio works, but if anyone wants me to check, I can do so.
So to all those who want to buy a Duet... upgrades are available that will make them sound better...in some cases, as with the Duetta, dramatically better! Start saving your shekels, people; and get in line to have your Duet Receiver modded. Of course, if you want to use the Duet's analog outs, you're going to have to look elsewhere. For someone who already owns a DAC, or was planning to get one, this is a no-brainer! I think I'm saving my place in line to get my second receiver modded...
Ajay
