RDA-7.1 Setup and Listening Tests

Set-up was a bit of a hassle. This amplifier is extremely deep (almost 2 feet in depth) and heavy (over 115 lbs!) This is a certain recipe for a hernia if you dare move it by yourself. Use caution (though I don't always practice what I preach and am usually too impatient to wait for others to help.) In typical fashion I opted to install the amp myself, lifting it onto my rack above my head. It was no fun and I still have a reminiscent back ache and strain to remind me. Be careful!

Aside from the enormous girth of the RDA-7.1, it had an ergonomically laid out back panel with plenty of separation of line level and speaker level connections between amplifiers. Since I was reviewing the new Integra Research RDC-7.1 matching processor I opted to connect it via the balanced inputs.

Editorial Note on Balanced vs Unbalanced
I measured the voltage gain of the RDA-7.1 via balanced and unbalanced inputs and found the following:

Unbalanced: Av = 29dB (THX standard)

Balanced: AV = 23dB (6 dB lower than unbalanced)

This is a standard practice in most consumer and pro audio. The preamp therefore usually has a +6dB boost via the balanced outputs to compensate. I verified the RDC-7.1 pumped out over 7Vrms via unbalanced and a whopping +15Vrms via balanced unclipped signal which was over 3 times the amount needed to drive this amp into clipping. Check out our Balanced vs. Unbalanced Connections Article for more information.

Listening Tests

I have always been of the viewpoint that sonic differences between well-designed amplifiers are very difficult to discern, provided that they are operated in their linear operating region. Get the output impedance and noise floor low enough, and the amplifier will generally not hiccup at any speaker load, allowing itself to be removed from the sonic chain of the system. That being said, I felt the RDA-7.1 was extremely neutral and transparent. It had the sonic quality of my old Aragon 8008 series (an amp I am dearly fond of) in that it sounded very BIG, crisp, dynamic and real, while at the same time quite, delicate and fluid. Feed it a good source and be rewarded with excellent sound, feed it a garbage source and be equally rewarded with garbage sound. It's that simple.

Two-channel Audio

As I have mentioned in other reviews, this SACD remains one of my benchmark discs for good reason - lumpy jazz in a smooth jazz environment. You won't find repetitive and annoying saxophone scales, single stroke drumming, and simplistic guitar rifts. Instead you're showered with snappy jazz and provocative lyrics, slamming drums and memorable instrumental solos. The SACD layer of Track #2, "Morning Grace" sounded about as good as I've ever heard which in one word would best be summed up as "phenomenal". The RDA-7.1 had no problems conveying all of the dynamics of this recording without introducing any coloration, all without breaking a sweat. I was hitting unstrained SPL peaks of over 105dB at my listening position without incident. I found myself cranking the volume higher without the typical listening fatigue when listening to lesser designs.

I put in another reference disc, which again happens to be a Patricia Barber Modern Cool from Premonition Records. If you really want to show off your system's dynamics capabilities, this is a must have disc.

Track#7 "Company" will reward time after time, especially during the explosive drum solo half way into the song. Wimpy speakers dare not play this track, and the same applies for flea watt amps. The RDA-7.1 really shined with this recording and was able to drive my reference system as well as the best gear I have had the fortune of reviewing.

Multi-Channel Audio

After expending considerable thought, testing and evaluating amplifiers over the past couple of years I have come to the conclusion that if a multi-channel amp can deliver solid two-channel performance, has a robust enough power supply to almost double power as load impedance halves, it will equally shine in multi-channel applications. After my two-channel listening experiences with the RDA-7.1, I came in with high expectations for multi-channel performance and it certainly didn't disappoint.

I am a sucker for instrumentals, especially those emphasizing drum ballads. The multi-channel DTS DVD Audio disc of Blue Man Group - The Complex is a shining example of such a recording. Track#3 on the DVD-A layer featuring Dave Matthews is a killer sounding song and is even cooler on the DTS side since you get to see the Blue Man Group in action spraying paint on each other, playing unconventional instruments, and watching the world around Dave Matthews transform between reality and cartoon. Very cool indeed. Track #1 jumps right out at you and gives your system quite a workout.

The RDA-7.1 was up for the challenge and continuously belted out the tunes without missing a beat. I found myself listening to the drum ballad on the DTS DVD Video layer over and over in awe at how cool it sounded, particularly on the Integra Research RDC-7.1 and RDA-7.1 combo overlaid in Pro Logic IIx Music Mode. This was a truly phenomenal experience.