Podcast #633: Use an AVR for Pre/Pro or a PreAmp?

Use an AVR for Pre/Pro or a PreAmp? We recently reviewed the NuForce AVP-18 all-digital HT dedicated preamp/processor (MSRP $1095) paired with the NuForce MCA-20 multi-channel amplifier (MSRP $1995). Our goal was to compare the performance of separates with the performance of a high quality AVR to see how they’d stack up. We used to hold the position that for just about everyone, the AVR would be more than good enough.   In may be an overstatement to say that we did a complete 180 on our position on separates; but we have certainly changed our tune.  While the all-in cost of the NuForce setup would run a cool $3090, and is a tad higher than we’re used to paying for a self-contained AVR, the performance and quality are there to back up the price. Is it worth it for everyone? Of course not. Is it worth looking into if you want great audio quality? Absolutely.   Not so fast… But wait, many modern day receivers actually include PreAmp outputs so you can bypass the internal amplifiers altogether and run the sound through an external amp like the NuForce MCA-20. Essentially turning the AVR into simply a dedicated Pre/Pro (Pre-Amplifier / Processor). What if you already had a Receiver you loved and you could simply run the audio through an external amp - would that give you the best of both worlds?   We decided to put that question to the test in a follow up to the NuForce review. We again stacked the Pioneer VSX-1120-K and the Denon AVR-3806 against the AVP-18, but this time used the same MCA-20 for all comparisons. What would it sound like if we simply used different processors to do the same job? After all, they’re all converting the same audio formats, like Dolby TrueHD or DTS Master Audio, from digital to analog, so shouldn’t they all be roughly the same?   Background We’ve heard people claim in the past that any processor decoding dolby digital is going to sound the same as any other processor performing the exact same job. Of course we know this isn’t true, but it is a common belief. There are even those who believe all amps basically sound the same. But that’s like saying all 300 horse-power engines are alike. We know this simply isn’t true. For all of the cases. But could it be closer to the truth for some than others?   Results The results didn’t really surprise us. Please keep in mind that we review according to our perceptions - according to how we hear the sound with our ears. The tests aren’t scientific as much as they are anecdotal. Your mileage may vary. But if you forced us to choose a hypothesis before beginning the experiment, it wouldn’t have been too far off from what we experienced.   Bottom line, both the Denon and the Pioneer sounded better when using the external MVA-20 amplifier. We tested using the same Klipsch Reference and HSU Research speakers as the last comparison. The Denon sounded the best of the two receivers, but we felt like the Pioneer actually got the biggest boost in overall audio quality from the test. To our ears, the Denon starts out sounding better, and it ended  up that way as well. The Pioneer, however, either has lesser quality internal amps, or was able to do a better job running the external amps, and it showed the biggest improvement.   But, when it was all said and done, neither the Denon nor the Pioneer sounded better than the NuForce - to our ears at least. They were closer, and actually in many areas harder to distinguish differences than the last round, but still not quite as good. In the spirit of openness and honesty, Braden was so impressed by the first round of NuForce review that he decided to acquire the pair for use in his own home theater. It’s entirely possible his ears were experiencing a little bit of irrational exuberance as a result of the purchase.   But removing any irrational exuberance, the final conclusion makes logical sense. A device purpose-built to deliver the best possible audio experience for the price outperformed the devices engineered to pack as many features into a price point as possible. Yes, you sacrifice features by going with the dedicated PreAmp, and yes it may age out a bit quicker as a result of that. But from a pure sound experience, it was top notch.   Conclusion If you have an existing home theater receiver with PreAmp outputs, will you get a sonic benefit by pairing it with an external amplifier? In our limited experience, yes you will. The amount of difference you get is based on the processor itself, the amps it has bundled internally, the amp you choose to pair it with externally, and the speakers you’re driving with it. But is it a good first step toward dedicated separates? You bet it is.   There are trade-offs to any home theater upgrade or investment. Some will produce higher dividends than others. You have to weigh all the factors when choosing where to invest your hard earned cash. For some, moving to separates, or even baby-stepping there by running an external amp with your existing receiver, is the next, right investment. for others it isn’t and it may never be. For many out there listening that killer receiver you just bought is great, and it’s all you’ll ever need. for those who know it could sound better, there are options for you.