Hi everyone, thanks first of all for populating this forum with extensive information for sound lovers.

As the title says, I’m looking for quality improvement there, but without knowing if I would get “bang for the buck” as American say (I’m not, I’m french, so sorry for the bad english…).
I moved recently from a Pioneer 454 SACD dvd player + Yamaha 1400RDS 5.1 system to a dedicated HTPC, with an Auzentech Prelude 7.1 soundcard, that is still plugged to the Yamaha, but to 7.1 speakers now.
The main difference is that I’m using the analog outputs of the Prelude (which is the main idea behind buying this thing), to feed the A/V receiver, selecting “multi ch input”.

So all the sound processing (e.g prologic IIx from AC3 tracks) is done by the PC, using various software (power DVD or VLC to name a few). The receiver is only “passed-through”.

I must say that from optic or coax output, decoded by Yamaha, to analog output from the Auzentech, with no digital processing from Yam, I saw a massive increase in quality. The sound is richer, crisper, less neutral, less “flaten” (if any of these can help you figuring out what it sounds ).

Now, after reading a lot about separate power amplification, and narrowing down to Outlaw 7700,7200 (or 7125?) product (precisely for the bang for the buck thing, as reviewed by many..), I’m wondering if:

I’d get such a pleasant surprise if I got rid of the yamaha, to put the Outlaw behind the sound card instead, or if I should keep the Yamaha for the 4 surrounds and buy a smaller dedicated power amp for the 3 fronts (2200?), or simply keep it as it is ! etc..etc..

I wouldn’t say money is no object as it always is, but I’d really like to be satisfied to find the optimal solution to de-bottleneck my installation, if there is a single bottleneck! I was so impressed by the improvement of the Prelude processing and analog outpu, that now I ask myself “are you missing something obvious that doesn’t cost 10k$ but would rivet you to your chair with happiness?”

Below is my configuration. I use this 70% of the time for movies, 20% for filmed music like operas, 10% for video games (to be increased :-P). My room in the basement is 20ft wide 21ft long, carpet on the floor and plaster walls.

The speakers I have are in home made cabinets , all 8 ohms, and incorporate the following:

sub: 269 SWR 51 XLS from Peerless 100W, + passive counterpart, individually powered by a 300W source.
center: 2* Audax HM100GB 40W with 1* Audax TM025 70W tweeter
Front: 1*Audax HM170G8 (60 W) and 1*TM025F1 tweeter (60W)
Surround: 1*Silverflute W14RC25, 60W and 2* Fostex FE87E ("rated input 5W, music input 10W" ?)
Back surround: Fostex FE127E rated 15W, music 45W?.


I would appreciate any feedback from people that “evoluted” like I could do, especially people that moved from Yamaha integrated receivers to Outlaw power amps, with or without keeping the Yam as a pre proc. What power would they advise me to get?
I would also welcome comment like: Your system is already very homogeneous, no bottleneck, keep it or change everything ! 
Again, thanks a lot for what you can throw at it, I’d be glad to give feedback on the installation I have, even though I’m more a PC geek than an audiophile.

First, your english reads fine to me.

Second, moving from the amps built into that Yamaha receive to a separate power amp (and I say this thinking of any of the three amps on your list, or even the little 7075) would be a nice upgrade.

Since your speakers are DIY, I'm not terribly sure what the overall efficiency of them might be. The RX-V1400 RDS is rated at 7x110W, although I don't know how that rating was achieved (may have been with just one channel driven). My suspicion is that a 7125 would be a nice "bang for the buck" upgrade. I went through a similar upgrade process a number of years ago, from Yamaha receiver to Outlaw receiver to Outlaw receiver plus separate amp, and each transition was a rewarding upgrade for me.

If you were to add a power amp, would you be planning to retain the Yamaha as a volume control or would you be using the HTPC's sound card software as a volume control? I'd prefer a component like the receiver for that role, but don't know enough about HTPC's to know what the practicality might be for going straight from PC to power amp.

Thanks a lot for your response Gonk.
First your point regarding the volume is very valid. I never thought of that. Adjusting the volume on an HTPC is not that practical, because you need a mouse nearby, and to come back to the window etc...But my case (crown CW02 from silverstone: tip: absolutely brilliant case, allows you to build a monster PC, yet totally silent because it has room for the right components) has a volume button, and a remote. It never occurred to me I would use it, but if I remove the Yam, then I will.
One good news is that you seem to think the 7125 would be good enough (I don't push anything to the max anyway), so the budget becomes very reasonable indeed.
Since I'm no expert, I can't make my mind on this power thing. It seems there's a consensus that the Yam & others' rating like 7*110 W is greatly exaggerated, compared to "all channels driven" ratings.
But then it comes down to an apparently very debated topic: the higher amp Wattage above speakers W the better? equal is fine? if amp is lower there's a risk of blowing the tweeter, is that an issue for common people? etc.. not forgetting what I read quite often: a powerful amp will get the speakers to "speak" at their upmost quality even at low volume...
So going for a dedicated power amp, is that only a question of power, or also a question of quality? I must admit that, not being in electronics, for me once the signal is generated (by the sound card in that case), that's it, an amp will not remove some voices or some crashes, or put a horn where there is none. But that may be where I'm completely wrong and overly incredulous about putting money in a separate amp.
Could you convince me a bit more?

As you are already thinking, a separate power amp is as much (or more) about quality of the power as about the quantity of the power. Much of our time is spent at power output levels well below the 75W mark (often even below the 15W mark). A separate amp has a much larger power supply, not to mention more robust individual amp channels and better cooling. As for speaker damage, clipping is probably the easiest way to hurt a driver - and it's easier to drive a receiver amp to clipping than a separate amp. Overpowering the speaker is possible, but that takes a very high volume level. Your ears may bring you to ease off on the volume before you get close to an "over-power" state (also keeping in mind that lower efficiency speakers are designed to handle the larger amounts of power required to get them to really high volume levels).

How would you score the improvement you got by changing the receiver, than by adding a power amp to your new receiver , from 1 to 100?
Or in other terms: did your other half/family i.e. objective people notice the difference and said: yes your investment is justified, I can really hear it and I wouldn't want you to come back to how it sounded before...
Not that it matters most, but these people are not dragged by the fact they invest money so they won't shy away from saying: nope, not a big difference.
Another question regarding 7125 Vs 7200 for instance: besides the added power, would you say there's a difference in quality of sound between both? or is it just because some people are compulsive about power (or live in a gigantic home?)

Hmmmm... The receiver and amp upgrades in question were 7 to 8 years ago now, so I hate trying to grade them. Also, they aren't ideal comparisons to your case. (The Yamaha receiver was a Pro Logic unit replaced by an Outlaw 1050 that had DD/DTS decoding and a better-than-average amp section.) Having said that, the Paradigm speakers that I added because of the receiver upgrade audibly benefited from the addition of a separate amp - most notably at medium to higher volumes.

As for the 7125 and 7200, I haven't heard either - I've used Outlaw's original 750, the Model 200 monoblock, and the 7500. Based on what I know of them, though, the real difference between the two is power. There are some large rooms and some very inefficient speakers out there that can need the extra power. There are also folks who just want the "peace of mind" of extra power. The two amps are built by the same manufacturer in California with comparable components.

I see. I've read my speakers info and they range from 89 to 93, more often from 91 to 93 dB. Not sure how this is a sign of quality or not but it seems, having read other threads, that the 7125 would power them well enough.
I have two very practical questions for you Gonk (seems you're the only "on duty" expert, or that my thread is awfully banal so nobody else is interested...or maybe this has been discussed a thousand times before :-) anyway thanks a lot again for your input)
So so,
a) if I remove the Yam, in order to connect my sub, can I find a female/female RCA adapter? because a male RCA is coming out of my Prelude, and my subwoofer cable is indeed another male RCA. Any issue with that?
b) If I were to keep the yamaha, maybe for the volume thing, or the subwoofer reason, or even the component cables "gathering" from Satellite and/or SACD dvd player (which I use rarely), is there a detrimental effect regarding sound quality to have an A/V receiver "in between" a high quality sound card, and a high quality power amp like Outlaw. If my aim is to gain power AND quality, shouldn't I remove completely the Yam or does it know how to be completely transparent?
c) have you ever heard of an electrical "blow back" effect that would fry my sound card or PC?, if I plugged the sound card outlet on the Outlaw directly? (I admit my ignorance of electronic phenomenon here :-)

Let's see if I can help here...

1. Yes, you can find adapters such as you describe. Locally, Radio Shack ought to have something, and there are a number of online sources as well (Monoprice probably, but I've also seen them elsewhere.
2. Keeping the Yamaha solely as a volume control shouldn't be detrimental since it should be a very clean signal path. I've never really done it myself, though, and I haven't used the 1400 so I can't be 100% sure.
3. No, I can't think of a way to blow out the sound card by connecting it directly to an amp - at least, not without doing something drastic (like hooking things up wrong and pushing the amp output into the HTPC.

How does the HTPC handle bass management, by the way?

Pepe, prior to auditioning the Outlaw products, my Yamaha 2092 handled the processing, switching and powered my Martin Logan reQuests. I did A-B comparisons between the Yamaha 2092 and Outlaw gear upon receiving it. I found the Outlaw 990 to be a nice upgrade to the processing of the 2092. Swapping the 2092 power for the Outlaw 7125 was even a larger improvement (than the processing) for my difficult to drive speakers.

I ended up upgrading the Outlaw 7125 to the 7500 because my speakers still sounded "compressed" --less so with the 7125 than with the Yamaha 2092--and have been extremely pleased with that choice.

I suggest trying the 7125 since it sounds like your speakers aren't too difficult to drive.

Rob

Very useful feedback guys, I appreciate.
Gonk, Re the bass on the HTPC, you're in the hands of the software here. Auzentech's enables to set the cross over frequency, and the volume of bass & treble.
I can also set the crossover at 80kHz on the Yam, and directly on my subwoofer. I have a separate volume on the sub too.
When I use multi ch input on the yamaha it's supposed not to do anything to the low frequency signal though, or any of them.
From the sound card, one jack becomes two RCAs (center and sub).That's all I can say, I don't know if that answers your question.

Candyman, that's exactly the kind of experience I was after. I checked those Martin Logan, they seem way above my specifications so the 7125 sounds a good option for my modest speakers :-)
May I ask again how would you describe the improvement from a receiver amplification to a dedicated amplification, in qualitative terms that is, since putting the volume at its max to wake up the neighbours is not what I'm after here.
thanks