As it stands, the 8053 is capable of putting out a balanced 16v signal. It does so by utilizing both positive and negative analog outputs for each channel. Since it has 3 channels (Front, Rear, and Non-Fader) it has two RCA outs for each, or 6 pairs of RCA preouts. One pair is positive, one pair is negative. Ideally this HU (and also the 8061) would be used with amps that accept analog balanced inputs. But, since most amps don't accept balanced imputs the Eclipse engineers created the BLA. Some amps that do accept balanced inputs via a 6-pin din input are Soundstream, Zapco, Coustic, Kenwood and others.
In terms of votage, the BLA produces 10v max (see specs). I know this is kind of difficult to understand, so let me explain it to the best of my knowledge. Since most amps don't accept balanced inputs, the BLA actually takes the balanced 16v input from the HU and converts it into an UNBALANCED 10v output to the amplifier. If you just run your standard RCA's off the HU preouts, then you get an 8v UNBALANCED signal. So, you might be asking yourself, why would I even run the BLA just to get two more volts??
The answer to that question is noise cancellation. Since cars tend to be noisey and have long RCA runs from the HU back to the amps, the Eclipse engineers brought high votage balanced outputs that can be found in high-end home audio arena to Car audio. The BLA uses a circut that polarizes the singnal and in doing so sends nice and clear music to the amps (see the notes from the manual).
So, by the time the signal gets to the amp - after the BLA magic - you have a noise free signal (accoring to Eclipse!). And you also get an addtional 2v over what you'd normally get from the HU alone. Since Eclipse decks use low output impedance in their head units, the BLA helps magnify the effect of all three facets of a clean signal: balanced, high votage, and low impedance. It's all about preventing the signal from degenerating on it's way to your speakers.
I really like having the high voltage signal. Some may argue that it doesn't matter if your HU puts out 2v or 20v....the amplifier's gain sensitivity can make up for it. In my experience the strong signal is a major benefit to my sound system.
Since installing the BLA, I have not had to set the gains on any amp I've used so far (about 10 of them or so). It's nice to be able to turn the volume all the way up (80/80) and not hear distortion. Now I've never put my system on a scope, so I don't know if it is clipping or not at max volume, but I've heard that it won't clip. To my ears, it's not.
So basically the way I set my gains is by using either the HU itself or my processor to level match the drivers. I've done it by playing sine waves and measuring voltage with a DMM, but I've found my ear works just as well. I don't beat the crap out of my system, so I think I'm on the safe side. I've never blown a driver yet [knock on wood].
- Improved S/N ratio
-Clean, high voltage signal
-Having the back of your HU essentially 6" away from your amps.
-No need for RCA's between the BLA ouputs and the amp (if you can get the it close enough)...except for the non-fader channel.
-Running 6 pairs of RCA's to the BLA I suggest you find very thin RCA cable for this job!!
-The Front and Rear ouputs come off the unit and are the standard male RCA plug. The Non-fader output is on the other side of the unit and you have to have a pair of male-male RCA's for it. Never understood this.
- You have to provide B+, grnd, and remote turn on leads. Kind of a PITA.
- The 10v output could possibly clip some amps. You never really get 10v on a consistant basis as that number is in reference to max.
Aside from being a PITA to set up, it's really nice to have virtually noise free delicious SQ from the 8053 piping hot for your favorite amp! If your system is noise free to begin with, consider yourself lucky and don't buy this piece of equipment.
Here are the specs for the BLA (37601):
Supply Voltage: 13.8V DC (10.8 ~ 15.6V)
Current Consumption Approx: 0.25A max
Frequency Response: 20 ~30.000Hz, ±2dB
Distortion: 0.005% (1Hz, 1V)
S/N Ratio: 106dB (IHF-A network)
Input Impedance: 12kΩ
Output Impedance: 220Ω
Max. Output Voltage: 10V (1kHz)
Common Mode Rejection: 60dB (1kHz)
Dimensions (W × H × D): 6.14˝ × 1.50˝ × 1.97˝ (156 × 38 × 50mm)
Weight: 0.72lbs (0.33kg)
From the manual:
In professional audio the preferred method ofsending an audio signal from one component to another is balanced audio delivery. Balanced line outputs virtually eliminate the possibility of noise in an audio system. “Noise” is defined as electrostatic interference, usually radiated from
wires and cables or other components which can filter into a sound system and degrade audio quality. Compared to standard audio cable, which
carries noise along with the audio signal to the amplifier, a balanced output uses two oppositely polarized wires to carry the audio signal. If noise is introduced into the system, it will appear on both audio signals. At the receiving end is a special “Balanced Line Adapter.” This “Balanced Line
Adapter” effectively cancels out the noise and sends only the audio signal to the amplifier.