Preamp output voltage?

Could someone please explain preamp output voltage? What effect (if any) does it have on amplifier performance, S/N ratio, dynamic range, and most importantly, subjective listening? I have an old Adcom GTP-500II tuner-preamp with a rated output of 2.0V RMS and a peak output of 10.0V RMS. I am considering replacing the Adcom with a new AV surround receiver, and I would use the pre-outs to power my front KEF 104.2's with an Adcom GFA-555II amp. I am looking at the Outlaw 1070 receiver, but it only has a pre-out voltage of 0.76V. The Yamaha RX-V657 receiver claims a pre-out voltage of 2V. Will either of these receivers (or any other receiver) be likely to sound as good, driving the Adcom amp, as the Adcom tuner-preamp for 2 channel music?
The lower the output voltage the higher you will have to turn up the preamp to achieve the same volume as one with more voltage. And you will probably hear more noise from the amp and or preamp when the volume is turned way up.
1. Preamp output Voltages are only loosely standardized. The Outlaw receiver may well have as much unclipped output as the Adcom.
2. Preamps generally are rated by gain in deciBels. 20dB is 10 times Voltage. (Double or half Voltage is 6dB.) The line stages in old (say, more than 10 years old) preamps generally had more gain than modern linestage preamps. This matters only if you have too much gain or too little gain. The former will have you listening fairly loudly with very little twist of the volume control. The latter will have you not being able to play your system loudly enough even with the volume control full up. GENERALLY, one wants to run the volume control somewhere around 'noon' or higher, as that's where the stereo controls have closer interchannel tracking.
3. None of this has much affect on amplifier performance, S/N ratio, or listening quality as long as one avoids the too-little or too-much-gain situations.
4. The quality of the audio will be a result of overall quality of the preamp and NOT its Voltage output (as long as one avoids the too-little or too-much situations).

I suspect you're worrying too much about this. If you want the Outlaw, buy it--you'll have a month to return it if it doesn't meet your needs.
you might be missing something since .76V output seems to me an absurd for any preamp.
Thanks for the helpful feedback! Yes, I do fret over minutiae before buying something new. Isn't that part of being an audio nut? :)

With the Adcom GTP-500II preamp, the volume knob travels from about 7 o'clock (zero volume) to 5 o'clock (max). Using my Adcom GFA-555II amp, usual listening level is about 9:30 or 10:00, 12:00 is uncomfortably loud, and the drivers on the KEF 104.2's are destroyed by 1:30. (That experiment was performed twice.) So based on the comments received here, perhaps a preamp with a lower output voltage would allow the volume knob to be safely turned up closer to 12:00.

Can anyone recommend any other surround receivers in the $600-$1200 range that might sound especially good as a pre-pro with the Adcom GFA-555II? I would like all of the current surround modes, but I don't need phono or video switching.

Here is a link to the review reporting the 0.76V pre-out voltage for the Outlaw 1070 receiver:
I once heard the Outlaw's receiver performance. For HT and price it's very descent. However the preamp section is realy weak. Therefore I would suggest looking at the used Rotel HT components.
I ran my Denon avr-3300 with an Adcom GFA-7500 for a couple of years and really enjoyed the combo. I had Energy Veritas at the time...Damn, they could play loud! On the rare occasion I had the Denon wide open and that Adcom just gobbled it up!! I had a Parasound amp until last night that I liked more, not better per say, just different. Hell, make me an offer on my Denon, you just might find you don't have to spend as much as you think you do to get what you want!!
I am not familiar with the Denon 3300 but I assume it does not have all of the current surround modes including ProLogic IIx etc... I would prefer to get as many of the currently available surround modes as possible. I almost bought the Denon 3805 but the weird remote was a deal-breaker. The other thing is that, darn it, I want gold-plated (or at least gold-colored) RCA connectors!

I just learned about the new Emotiva Ultralite pre/pro and 6/7 channel amp units that are supposed to start shipping next week. The specs and prices look very interesting, so for now the Outlaw is on the back burner until I see some reviews of the Emotiva.
P.S. -- Thanks to all for the feedback on pre-out voltage. I am seeing numerous comments in the Outlaw forums about how the 1070 needs to have its volume knob and/or channel trim controls turned up higher than usual to get a decent volume. This would seem to be consistent with the fairly low reported pre-out voltage.
Javachip - what did you decide on? The Emotiva or the Outlaw? For some reason I was unable to post a request for opinions on the Emotiva DMC-1 pre/pro, so I am going to try to piggy back here!

I know nothing about the Emotiva products and just wonder what reviews you may have read that made you decide for or against the Emotiva Ultralite you were considering.

I wouldn't fret about the output voltage from the preamp. In many cases the older units had higher outputs to justify the low S/N numbers and get above the internal noise. I have moved from the Adcom 555II preamp to the Outlaw 990 pre/pro and am very satisfied. I am also driving an Adcom 555II amplifer into JM Labs Daline 6.1 speakers. The outlaw will drive your amp just fine with actually less noise. Yes you'll have to turn up the volume knob a bit more. Sounds great though.