Power Amplifiers

Emotiva UPA-5 Five-Channel Power Amplifier

ARTICLE INDEX


Introduction

Over the past decade, lots has changed on receivers that we buy for home. We've gone from S-Video to Component to HDMI for video, replaced 6 RCA cables for 5.1 audio with a single digital cable, to having it integrated in the HDMI signal along with video. Receivers have added all sorts of new functions with better on screen menus, room correction, Ethernet ports for streaming media and firmware upgrades, and we have also moved from 5.1 channel audio, to 6.1, then 7.1, and now all the way to 9.1 or greater when using Dolby ProLogic IIz or Audyssey DSX. However, one thing on receivers has barely changed when I look back over the spec sheets: weight.

Receivers are now designed to drive almost twice as many channels of audio as before with their internal amps, but the amplifiers have typically stayed the same in weight, or even gone down, which leads me to believe that those amplifier sections are underpowered. Typical Class AB amplifiers that are found in receivers need large transformers to have power reserves to be able to drive speakers during dynamic passages in music or movies, and those alone can weigh more than a whole receiver does. For the majority of mass market receivers, they just don't have the power reserves when more than 1 or 2 channels need lots of power. My own Onkyo TX-SR706B is rated for 100 watts per channel, and in testing people have found that while it can do 122 watts per channel with 2 channels drives, when you drive 5 channels at once, the power output drops down to 75 watts. Imagine what adding 4 more channels would do to it's maximum power output?

Thankfully, many receivers have pre-out jacks that let you add an external amplifier to your receiver. If your receiver has a 9 channel pre-amp output, you can add an amp for as many channels as you want, and since the internal amp is working less, it can power the remaining channels better than it could before. When I saw that Emotiva had announced a new 5 channel amp in their Ultra line, the UPA-5, I quickly asked if they could send one over so I could hook that up to my Onkyo and see what benefit an external amp might provide me.

Specifications

  • Design: Five-channel Power Amplifier
  • Power Output: 125 Watts RMS x 5 into 8 Ohms; 185 Watts x 5 into 4 Ohms
  • THD+N: 0.1%
  • Connectors: RCA Unbalanced and XLR Balanced; Five-way Speaker Binding Posts
  • Dimensions: 7.8" H x 17" W x 19" D
  • Weight: 58 Pounds
  • MSRP: $549 USA
  • Emotiva