Peachtree iDecco D/A integrated amplifier
So it was that Wadia Digital's first iPod dock, the Model 170, earned its status as a seminal product; and so, I daresay, will Peachtree Audio be recognized for pioneering yet another worthy genre with their iDecco: a perfectionist-quality iPod dock and a similarly pedigreed digital-to-analog converter, combined with a tube-buffered preamplifier and a 40Wpc power amplifierall for $999.
The US-designed iDecco, which is manufactured in mainland China, has its origins in the Peachtree Nova ($1199), a similar DAC-integrated with a little more power (80Wpc) and a lot less dock. Having earned dozens of rave reviews, including John Marks' writeup in "The Fifth Element" in the August 2009 Stereophile, and with retail sales nearing the 4000 mark, the Nova endures. But Peachtree's David Solomon now seems ready to bring the gospel of good sound even nearer to the audio-indifferent.
Solomon describes the genesis of the iDecco: "We simply started reading RIAA statistics, and there it was: Look what's happening! Consumers have changed the way they buy music, and [the world of downloadable media files] is where they are."
The Peachtree iDecco is designed around a traditional linear power supply with a toroidal transformer: Thankfully, wall warts are neither required nor supplied. (I'll probably never accept the idea of four-figure domestic audio products that use the same sort of AC adapter as a Hello Kitty portable CD player.) For its part, the power amp is built around the TDA 7293 power MOSFET IC from ST Microelectronics, operated in class-A/B. The preamplifier's solid-state gain stages run in class-A, while some degree of driver-stage buffering is conferred by a 6N1P dual-triode tube. As in the Peachtree Nova, the tube buffer can be switched in and out via a pushbutton on the remote handset, a function not duplicated on the iDecco's front panel; given that the tube is "ramped in" to the circuitwith full rail voltage on the plates at all timesthe changeover takes only a few seconds. Solomon says that, with the tube switched in, "we lose about 6dB of signal/noise ratio. But I think it sounds better."
The D/A board is where things get really interesting. The star of the show is an ES9006 Sabre DAC from ESS Technology, of Fremont, California. According to Solomon, the Sabre DAC reclocks the datastreams from all digital sources, and upsamples them to 24 bits and 96kHz. Solomon also says that the iDecco's D/A board incorporates 11 regulated power supplies of its own, to enhance interstage isolation and thus keep noise to a minimum.
The iDecco's USB transceiver is separate from the ESS Sabre DAC, and is galvanically isolated from the rest of the board. "We learned early on we had to do something about noise coming off the USB cable," Solomon says. The USB socket and the iPod connectionthe latter is purely digital, and bypasses the player's headphone outputare also transformer-coupled to the circuit, to prevent grounding glitches and switching noise.
The iDecco's front panel is simple and spare: That lucky tube gets its own little window, flanked on one side by a (motorized) volume knob, and on the other by five illuminated source-selection buttons. All front-panel controls are duplicated on the pleasantly rubbery remote-control handset, alongside such extras as a Mute button and the aforementioned tube switcher. Additional buttons on the handset can be used to control the most basic playback functions of the iPod itself: skipping forward or backward through various songs (but not albums), pausing the music, and resuming play.