In reading about balanced outs, it seems a number of devices with balanced outs are not balanced throughout the system. (Not sure if I'm wording it correctly.)

How is it handled in the 990? Is it throughout or is it the same out to the RCA's, just connected to XLR's?

Thanks!

Either nobody knows or they don't want you to know...

I don't know about the 990, but very few items are actually fully balanced throughout. My guess is that the 990 is not and only the output is balanced. I design both Medical and commercial electronics and the question of whether to use a balanced design always comes up. In general given the state of electronics today there is little benefit in having a system fully balanced througout. Have interconnects balanced makes sense as common mode noise is reduced as is any external noise introduced in the cable run.
I'm not saying that there is not a benefit is some applications, but with the high quality of solid state IC's it is minimal in most applications. In fact if the balanced design is implemented haphazardly, it will actually make the situation worse.
As a rule of thumb, noisy environments (like long cable runs) benefit from fully balanced, close proximity quiet systems do not.
BTW it also applies to digital as well, hence the use of AES/EBU.
I am taking a very simple approach but like most things, whether to fully balance or not is complex and a matter of design criteria.

The 990's analog section may not be fully balanced (I don't recall hearing either way - Outlaw support could give you a definitive answer). I do recall seeing something that indicated the planned replacements for the 770 and 755 (the 7700 and 7500) and the big 790 will be fully balanced designs, but we don't have much solid info on those.

Hey Outlaw! How about some info. :rolleyes:

Outlaw generally stays out of most forum discussions (although as soon as I post this, Scott will probably chime in) - they provide us with this forum and monitor it, but keep something of a hands-off approach. That's why I recommend checking with Outlaw directly (by phone or their support site ).

Has anyone compared the sound quality using the XLR's vs the RCA jacks?

gband sums it up well:

Read this to understand what is going on:

http://en.wikipedia.org/wiki/Balanced_audio_connector

The 990 is NOT fully differential.

It's pretty amazing they included balanced outputs for the price. To include discrete signal paths for both the positive and inverted signals for all seven channels would just not be possible at this price point. It's also incredibly hard to do correctly.

A quick peek under the covers confirms all of this.

This is not to say that the balanced outputs are not welcome. I for one will be using them since all of my amps are fully balanced designs. I just wish they had included pass-throuogh XLR inputs for stereo. You can't have everything though.