I have the feeling that 970 is 1070 without the power amplification stage, which comes separately (as 7075).
Can anyone confirm or deny this?

I believe the 1070 came first...
and then Outlaw decided to market the same platform without amps...

That is exactly correct - the 1070 was developed initially and launched around late summer of 2005, and the 970 was released around the end of 2005 by simply removing the amp section. They are otherwise identical units.

For what it's worth, the 7075 has no relationship to the 1070's internal amp section. It was designed and is manufactured completely separately from the 1070.

Thanks, guys.
How comes you know all these about Outlaw products?

- As my post count might suggest, I keep a pretty close eye on the Outlaws.

Full time, I might add ;-)

But in order to be able to know what's inside a component or other, a little bit more might be required, some info coming from elsewhere than only these posts.

You might also be able to explain why a processor like 990 is so big, when it doesn't need a huge transformer and heat sinks? It's the biggest single thing in Outlaw's panoply...

Oh, Outlaw actually said that the 970 is a 1070 minus the amps. And the 990 is the size that it is because it is based on an existing platform (the Sherwood P-965), which is a platform that was developed as a receiver initially (the Sherwood R-965). The chassis size was dictated by the need for seven amp channels - the P-965 just left the sides of the rear panel empty when the amp channels went away, but the 990 used those areas to fit in the balanced outputs and DVI connections.

I thought some Outlaw release of the 970 mentioned something about 'tweaks' to the hardware in the 1070 to develop the 970. The only thing I see on the description page of the 970 is mention of "performance matched op amps in the critical path". I'm not even sure what that is...or if the 1070 has that as well but it could be a minor difference in the two units.

gonk, now that you mentioned the balanced outputs, let's open that can of worms.
990 has balanced outputs, which means one phase splitter per channel just before the XLR outputs(8 total). Also, the receiving power amp needs one differential amplifier per channel to implement the common rejection mode (7 total).
Thus, per channel, you have two active components in the analog signal path only to reject the noise picked up by a pretty short interconnect in most cases, running from the processor to the power amp.
I guess you see the question coming...
Do you think this is worth it? Do you really feel a positive difference between connecting the 990 to its power amp in balanced vs non balanced mode?
I "feel", for I haven't tried it myself, that the addition of the phase splitter and dif amp in the analog signal path adds up to be more distorting than the minute noise picked up by the high quality interconnects.

You have a good point but I dont think 990 have two active components in the analog path. Normally, the designer will convert the existing differential signal to single ended by a passive component like a transformer.
Just a though.....

Alexandru, there's a great debate way back in the early days of the 990 forum about this very subject in which one very knowledgeable contributor (soundhound) presented much the same argument that you do: a more complex signal path is inevitable with balanced connections, so he didn't recommend using balanced connections unless you need them for the purpose that they are intended to address (noise/interference from outside sources over long cabling runs).

SP72, a transformer is usually found in very high-end or professional gear, for it's way more expensive than an op amp. Not to mention 7 of them. I stronly doubt power amps one might hook a 990 to will have them, for those players are in a different league. But, nevertheless, your point is correct. It doesn't HAVE to always be two active components in the signal path.

Gonk, I can only feel honored for being mentioned in the same phrase with a very knowledgeable contributor, which by no means I am. My hi-fi experience is mostly theoretical (I'm an engineer), but I don't own high-end gear.

Please forgive my newness to the site. So bottom line, is there any audio advantage for one model (1070) over the other (970/7075 amp combo). I am ready to purchase one or the other and like the idea of the separates for future upgrades, but is it worth the extra $ 300. Is there more power with the combo? Opinions appreciated!

Welcome to the site, Dave!

The 7075 will offer almost no difference in rated power over the 1070's amp section - 10W or so isn't going to be audible in and of itself. The 7075 will offer an amp section physically isolated from the more sensitive pre-amp electronics, a larger power supply (for more ably handling transients produced by very dynamic music and movie soundtracks), and a potentially easier upgrade path down the road (keep the amp, replace the "brains"). Plus, if you have any need for a subwoofer, you can get an LFM-2 for free at the moment with the 970/7075 combo.