A/V Veteran

Heat is the enemy of electronics, including all of that audio gear crammed into your A/V cabinet. In the early days of electronic entertainment, vacuum tubes (or as our Brit friends call them, valves) were the thing—the only thing. As one of my teachers once explained, the key to vacuum tubes was the little man with a switch inside. But he must have been sweaty, as a tube device could serve well as a space heater.

Back in the day our electronic entertainment consisted of little more than a radio. The family gave no thought to what was inside until one of the tubes failed, prompting a visit to the local drug store with its tube tester and ready supply of replacements.

Then came hi-fi and an interesting thing happened. Because of the heat issue, relegated largely to the output stages of an amplifier, separates were born. The separate preamp driving an amp on a separate chassis was a popular way to go.

The divide between separates and the integrated amplifier (or perhaps AVR) still exists today in both the 2-channel and home theater worlds. Long forgotten is its genesis, since heat is no longer an issuewith solid state electronics.

Or is it? For 2-channel audio gear that may be true, though extra cooling is never a bad idea, particularly where space for ventilation is limited. But the audio-video receiver is another issue. With nine (or more) 100 watt (or higher) solid state and (usually) class A/B amps enclosed in a chassis only slightly larger than a four-slice toaster (analogy intended!), heat is back with a vengeance.

Some of today's AVRs, and even separate amps. come with a cooling fan pre-installed, often with basic sensors to turn it on when needed. But such fans are sometimes either ineffective or noisy. Recently, while driving a new pair of speakers under review to high levels, I was made aware of the fan on the Denon AVR-X6700H for the first time. It wasn't loud, but immediately after the audio chaos ended I heard it making a faint ticking noise, just audible from my listening seat 8-feet away. The fan didn't help much; the Denon was still uncomfortably hot to the touch.

Concerned about this, I learned that external cooling fans for such equipment were definitely a thing. Yes, you can buy miniature fans for under $20. But a short Google search turned up AC Infinity, a company offering not only a wide range of separate fans but also self-contained fan systems consisting of three small, internal fans linked to control circuitry. Built into a thin case, they physically match many AVRs in width and depth, a perfect fit atop not only on our loaner Denon AVR but also for my Marantz AV8805 pre-pro. The latter has no amps on board, of course, so doesn't run nearly as hot as the Denon. But it does generate heat, so an add-on fan for it still makes sense.

Driven by a small, separate power brick, the top-line AC Infinity Aircom T-Series offers the most control flexibility. I ordered the company's Aircom T8 with rear exhaust at $119. Similar models are available with top or front exhaust, as is a less expensive Aircom S-Series with fewer adjustments. The controller is also available separately, for use with individually purchased fans strategically positioned as needed to cool an enclosed cabinet or equipment rack.

Since I was in a rush and planned to keep the T8, I bypassed the usual review-request route and bought the T8 outright. Amazon Prime was cheaper (no shipping costs) and much faster, to here in Florida, than ordering directly from AC Infinity in California.

All of the self-contained AC Infinity T- and S-Series models add just under two inches to the height of your AVR, so make sure the combination will fit. With the rear or front- exhausts models you won't need extra space above the pairing for ventilation, but it won't hurt to have it. Should the AC Infinity ever fail, you don't want to have to have to disconnect, move, and reconnect your AVR (with all of the hassle that entails) until the AC Infinity is repaired or replaced.

The small Aircom Series owner's manual is a bit cryptic, but setup wasn't difficult. There are several different operating modes (I chose Auto), set via the small, LCD-lit, front panel controller that provides a range of useful adjustments and information. Most important, it senses the current temperature and lets you set the maximum level before the fan kicks in. There are five different fan speeds. The latter can only be set in the On operating mode, but that setting then applies to all other modes. I never needed to go above fan speed 3 except once, and most often set it at 2. In those settings the fan noise was never intrusive at my listening seat. Two USB ports in the back can also be used to add up to six additional AC Infinity fans, if needed, with those fans also controlled by the same front panel settings.

The only issue I experienced was when I set the Aircom T8 to its Off mode. I did this once, forgot about it, and then fired up the AVR. The Denon got very hot, with most of its ventilation blocked except for the heat able to pass through the fans ports, make a right turn, then exit out the rear with no assistance from the inoperative fans. When I discovered this I immediately turned the AVR off, set the T8's fan speed to maximum (5) and set the fan engagement temperature, normally at 85, down to 75 to keep the fans moving until the AVR dropped to near room temperature. No damage was done, but I learned a lesson and thereafter left the fan in Auto mode at all times. With the fan engagement temperature set to 85, the fans will remain idle in the Auto mode when the AVR is off and cool.