Setup and associated equipment
I believe the vast majority of people interested in iFi products will probably use them in a computer setup or with a moderately priced or inexpensive audio system; either desktop or traditional two channel audio. With this in mind, I decided to audition the various iFi components with my Virtue Audio M451 Sensation integrated amplifier, rather than my usually more expensive electronics. An OppO 981 DVD player normally used as a transport for reviews operated solely as a CD player in conjunction with the iTube.
The only exception to the moderate price rule for this review is my AAD 2001 stand-mount monitor speakers. I chose the AAD 2001 speakers, rather than lower price speakers I own, because of their resolving ability. They are able to reveal any changes to the equipment played through them.
iTube – $299
The iTube is unlike most other tube buffers I have experienced or have seen in the marketplace. Most other tube buffers are just that, what you see is what you get. A few include a line level preamp section, and a few others will also feature a built-in headphone amp. What does the iTube offer besides the class A active tube buffer, with adjustable gain settings of 0 dB and 6 dB, for the paltry $299 retail? Well, it can also be used as a single source analogue preamplifier, with the same two gain settings. The device includes some interesting features I’ve not seen currently offered by competitors, these being Digital Antidote Plus (DAP) and 3D Holographic Sound, with both using analog filters for operation. DAP is actually several decades old, invented to smooth the harshness inherent in many early CDs, by way of time and phase correction. The 3D Holographic feature is supposed to widen the soundstage of bass frequencies to match the higher range frequencies, with the narrow setting for desktop speakers (switch up) and normal setting for the typical room speaker position (switch down). The 3D feature is off with the switch in the middle.
Included with the unit is an ultra low noise power supply, a pair of generic RCA cables (the kind formerly included with mass produced audio gear), information/warranty card and a tiny screwdriver to facilitate moving the underside micro switches. The information/warranty card describes the various features and functions of the unit. There is a caveat emptor that the iTube should only be used with the specially designed power supply and warns against replacing it with one of your own. In a word, don’t! Darren Censullo told me a few units were damaged as a result of owners switching to a different power supply.
Mr. Censullo also told me the iTube was designed to be sonically neutral, and added that an NOS GE 5670 tube was selected. Well, it happens I have extensive experience with the 5670/396a/2C51 family of tubes. I have auditioned Western Electric, Tung Sol, Raytheon, GE, and several other brands on different tube DACs. The GE was the closest to neutral of the lot. It thus makes sense that this particular tube was chosen to match the design purpose of the buffer. The iTube’s design also does not stress the GE tube, and Mr. Censullo happily said to expect approximately 100,000 hours of life, which almost made my eyes pop out of my head!
A nice design touch is a drilled out hole on the top of the chassis where the dot is on the first i of the silkscreen iFi. This was done to provide ventilation and show the illumination of the GE 5670 tube when the unit has been turned on. I think it’s pretty clever, but an impish move. I would actually like more ventilation on the chassis top since the unit gets quite hot to the touch after being on for several hours, due to inadequate heat dissipation.
I should also add that the iTube requires about 20-30 minutes of playing time before sounding its best.