Amp Power...what's enough???

[Pyezahn]

I purchased a decent pair of speakers ($1000):

Woofers: (2) 6-1/2 Glass Fiber Cone
Midrange Speaker: (1) 6-1/2 Kevlar Cone
Tweeter: (1) 35mm Cloth Dome
Frequency Response: 30Hz-20kHz
Impedence: 6Ω
Power Handling (RMS): 200w
Sensitivity: 89dB
Height 45-11/16"
Width 9-1/2"
Depth 20-7/8"

I was thinking about driving them with a Rotel 1057 AVR (5x75), yet the dealer thinks they might need more power and recommends the 1067 (7x120). Unfortunately, that's way out of my price range (I can buy seperates for this price).

I'm trying to figure out what I MUST spend to get the most out of these speakers without going crazy. I plan on running 5.1 with a ratio of 70/30 in favor of 2 channel music. Can anyone explain the tradeoffs and what will and won't work between these choices: AVR's: Rotel 1057, Pioneer 74TX; Pre/Pro: Outlaw 990/7075.

[Megalith]

A pair of $1000 speakers is considered high-end?

Anyway, I would go with pro amps.

[b curry]

Ask your dealer to let you demo the Rotel 1057 at home. While your at it ask for the 1067 too so you can A/B them. If he won't let you bring 'em home ask if you can bring your speakers in.

You would need double the power of each 75 watt amplifier section (2 X 75 = 150) to move the sound pressure level (SPL) 3db. So, the 1067 is 30 watts short of that. Meaning, the 1067 is not going to play very much louder as you generally have to move 3dB to perceive a difference in volume.

Anyhow, ask to try 'em out at home.

[cneely8]

>You would need double the power of each 75 watt amplifier section (2 X 75 = 150) to move the sound pressure level (SPL) 3db. So, the 1067 is 30 watts short of that. Meaning, the 1067 is not going to play very much louder as you generally have to move 3dB to perceive a difference in volume.

Also, there's the issue of "headroom," if you are a believer in that. I guess I am. I added a pro-amp, and while I'm sure I'm not using anywhere near it's 400 watts per channel on a sustained basis, it sure seems like the peaks, explosions, action scenes, etc are more detailed, full, and clear than using just my 3805. Could be psychological, sure, but for what it's worth, even the wife commented on the DVD improvement (my fail-safe test). For the record she was against the pro-amp idea until she heard it.

[b curry]

cneely8, your head room argument is certainly valid, and much more so than using it with a 200 watt example. But at the end of the day 200 watts is 3dB more SPL than 100 watts and 400 is 6dB. Why stop at only 6dB why not shoot the works and go for 9dB with 800 watts?

An amplifier will increase the current, voltage or both depending on it's design. It does this by taking power from the power supply and controlling output to match the input signal shape with larger amplitude. When the input signal exceeds the output, the amplifier will clip. All amplifiers can be driven to clip and most are. Normally the clip is so short we don't hear it. You probably can never have enough headroom or watts. However most people are using less than 50 watts for comfortable listening levels.

The OP had a budget and the fractional watts shouldn't get in the way.

[SteveCallas]

Go with a pro amp - you can get 200-400 watts per channel into 6 ohms cheap. As others have mentioned, it's only going to be in the bass and dynamic peaks where you might notice a difference.

[T-Bone]

Pyezahn,

You left out two important factors:
- how loud (meaning SPL) at the listening position
- how far are the speakers from the listening position

Assuming your mains are 12 feet from the listening position, an in-room wattage value to 50 watts will allow either one of the mains to hit 100 dB. That's pretty loud. Real loud for music... and for movies, that will allow for a volume of 5 dB under reference (too loud for me).

I won't provide feedback on the equipment that you listed... others have done that... just know that you won't use anywhere near the max watts specified for the speakers.

-T

[cneely8]

>As others have mentioned, it's only going to be in the bass and dynamic peaks where you might notice a difference.

I forgot about the bass. My rti12's had much improved bass response once I added the amp. Forgot about that.

>But at the end of the day 200 watts is 3dB more SPL than 100 watts and 400 is 6dB. Why stop at only 6dB why not shoot the works and go for 9dB with 800 watts?

I don't get it enough to reason through it. My logic stops at "it sure sounded better, in the following way..." As a result, I am sure I'm not using my optimal wattage and probably wasting some power or whatever. But like I said, I just go with the simple test of "did it sound better?" (level-matched, of course). It seems that for me, it's a test that has worked pretty well.

[SiriuslyCold]

check this calculator (http://www.crownaudio.com/apps_htm/designtools/elect-pwr-req.htm) out

[cneely8]

>check this calculator out

Very interesting. I didn't understand it way back when I first saw it, but now I do. Seems to lend credibility to the "headroom" theory, assuming the calculator is correct, of course.

Now the question becomes "how much headroom (in dbs) does one need for a standard action DVD?" For example, if i am listening at "x" db, then I should expect to need "X+what" for the most intense action scenes on your average action DVD?

[dsmith901]

As to the original post question - the old saying that "you can't have too much power" has much truth. For about $1K street you can get the Sherwood Newcastle A-965 (7 X 120w @ 8 ohms all channels driven) and IMO it is an outstanding amp with plenty of dynamic headroom (over 400 watts @ 2 ohms). Don't skimp on the power amp as it will last you a long time, as opposed to a receiver that will not only skimp on the power and put your speakers at risk, but will be outdated within a year or so featurewise.

[Pyezahn]

I agree with what you're saying, but given the circumstances, I need to make some sacrifices. I had budgeted myself $1200 for all my speakers (5.1), and planned on getting something like the Marantz 7500 AVR - a simple and inexpensive set-up that would satisfy my video needs. However, I'm a sucker for SWEET 2-channel music, and once I heard those speakers I eventually purchased - it was all over - no turning back. Now, with my entire budget blown on speakers, I need a good plan-b. I guess I can still purchase a cheap receiver, but I'm also guessing that that would cancel the great sound I hope to hear from those speakers. Is that a fair assessment? So what other options do I have? Well, considering that my home is still 6 months from completion, I have some time to stash my pennies. I agree that the amp is vital, and that will be my next purchase. The question is....if money becomes an issue (as wifey wants to spend it on other things for the new house), what do I do?

I have no prob with used equipment, so my first attempt will be to get something used, maybe a Rotel 5x125, or maybe even a b-stock Outlaw 7x120. If nothing there, then I'll blow a bundle on the Sherwood A-965 and wing the rest. Which leads me to my final question: is it okay to mix and match manufacturer's pre-pro's and amp's? I've seen several Outlaw 950's on ebay that I think could get me by until I have the money to upgrade. How would that 950 sound matched with a Rotel 1075 (for example) ?? My video needs are much MUCH less critical than my audio needs. Would it be better to wait until I can buy a set of something, such as the 990/7100 Outlaw combo? Any comments or thoughts are welcome!

[Gary Murrell]

ask me double the recommended speaker watts, in other words 400 watts ;)

but I am crazy :)

-Gary

[SiriuslyCold]

[QUOTE=cneely8]Now the question becomes "how much headroom (in dbs) does one need for a standard action DVD?" For example, if i am listening at "x" db, then I should expect to need "X+what" for the most intense action scenes on your average action DVD?[/QUOTE]

http://i6.photobucket.com/albums/y234/siriusc/misc/funy/040321headroom.jpg

seriously speaking though, I remember reading somewhere DD program material peaked at 106db; i.e if you were listening at reference level of 85db (although I'm not sure if the 106db peak was over all the main channels, individual channels or just the LFE)

although it seems extreme to expect a 21db headroom (max!)

[T-Bone]

Somebody correct me if I am wrong, but when matching pre/pros to amps (we'll assume different manufacturers of each), isn't it important to make sure that the voltage out of the pre/pro matches the input of the amp?

For instance, I've seen some amps that require as much as 1.5 volts input to attain watt the max output wattage rating... so if the pre/pro only offers a max of 1.0 volt output (seems to be common), will that be a concern to Pyezahn?

-T

[dmoeller17]

I upgraded a denon 2801 to B&K seperates (ref 50 and 200.5 amp) with my B&W 600 series system (which will be upgraded soon). I know the denon is rated at like 85 x 5 however sound vision reported it only did like 32 x 5 under the distortion specs denon gave in the book.

i don't really notice a huge difference in sound quality at normal volumes with these speakers (im sure i would hear a big difference if i had better speakers), but what i did notice was much better dynamics. Like when the orchestra would play fff it was not compressed at all and sounds much louder and "effortless".

Also i moved my system to the main living room which is open to the rest of the house (dining, kitchen, entryway, front living room) and obviously had to turn the volume uh much higher to get the same volume i was used to in a much smaller room. the sound would get bad on the peaks cause the denon was running out of steam, but with the B&K the sound is much cleaner at higher volumes.

[thylantyr]

Pyezahn;

This is what I would do. Since you found the two speakers you desire and plan to do
70% more listening in 2 channel mode, then get a high powered 2ch amplifier to drive
them and just get any ole AVR to drive the surround/center speakers since you
are on a tight budget.

Get a $300+ pro amp to drive your mains.

[Pyezahn]

This is exactly what I'm thinking. But I'm wondering - even if I have a 2 x 200 amp driving the main's, doesn't the receiver that's driving them have an effect on the sound? How will a 500.00 receiver sound? What would be some good (receiver) candidates???

[dsmith901]

[QUOTE=Pyezahn]This is exactly what I'm thinking. But I'm wondering - even if I have a 2 x 200 amp driving the main's, doesn't the receiver that's driving them have an effect on the sound? How will a 500.00 receiver sound? What would be some good (receiver) candidates???[/QUOTE]

That is somewhat true, especially if the receiver does not have a true analog bypass but rather digitizes all analog inputs for bass management. The 2 channel amp for the front speakers for stereo music is a good idea, but a good 2 ch amp will cost almost as much (or more) as the A-965 at street.

As for mixing pre and power amps I have done it for years and had no problems, so feel free IMO. Most pres will put out sufficient voltage for the typical power amp, though you may run across a few exceptions, so do check those specs. BTW, I have a fine H/K Signature 2.1 (5 X 100w) amp for sale at Videogon if you are interested, for a very reasonable price. Check out the ad or send me a PM.

[SteveCallas]

But I'm wondering - even if I have a 2 x 200 amp driving the main's, doesn't the receiver that's driving them have an effect on the sound? How will a 500.00 receiver sound?
I wouldn't worry about that, cough (http://www.avsforum.com/avs-vb/showthread.php?t=680019) :) , but instead of taking my word, I'd suggest you do some testing if you want to be sure.

[sjoh]

Hello Everyone,

It seems that most posters here seem to recommend going for the largest amplifier you can afford, but what about crossover distortion? If you are using a high powered Class AB amp and have it output relatively small signals crossover distortion is going to be significant since it does not scale with the output.

Regards,
Sejin.

[Bob Lee (QSC)]

[QUOTE=sjoh]Hello Everyone,

It seems that most posters here seem to recommend going for the largest amplifier you can afford, but what about crossover distortion? If you are using a high powered Class AB amp and have it output relatively small signals crossover distortion is going to be significant since it does not scale with the output.

Regards,
Sejin.[/QUOTE]

Possibly, depending on the amp's design and how it's biased. High-power amps aren't necessarily more prone to crossover distortion, though.

[sjoh]

[QUOTE=Bob Lee (QSC)]Possibly, depending on the amp's design and how it's biased. High-power amps aren't necessarily more prone to crossover distortion, though.[/QUOTE]
Hello Bob,

Thanks for your reply. I guess the point I was trying to make is that if you have a 100W amp and a 1000W amp, and both have 0.001% of crossover distortion, then at identical volumes the crossover distortion in the 100W amp is 10dB lower than the higher powered amp - if I understand the theory correctly.

Regards,
Sejin.

[Bob Lee (QSC)]

That would depend on at what output level the crossover distortion was measured. If the measurements are taken at the same output voltage, then neither amp will have more crossover distortion for a given output voltage, which wouldn't be unusual if they're of similar basic design.

[SteveCallas]

What exactly is crossover distortion? Are you referring to crosstalk between the amp channels?

[Bob Lee (QSC)]

Crossover distortion in a class B amp is the discontinuity in the signal voltage as it makes the transition, or "crosses over," between positive and negative polarities.

In a class B amp, one transistor or bank of transistors handles the positive voltage swings, while another handles the negative swings. Bipolar transistors, however, require about 0.6 to 0.7 volts across the base-to-emitter junction in order to really start conducting, so a straight class B amp wouldn't track the signal accurately in the zone between about -0.7 to +0.7 volt.

Therefore, we have class AB, in which the transistors on both sides are biased so they are slightly on at quiescence. This smoothes the transition, and a little negative feedback then helps make it more nearly linear.

At least in pro class AB amps, the bias can be adjusted with a trimpot to optimize the balance between linearity and quiescent current while taking into account tolerance variations among transistors. Too little bias reduces the quiescent current but increases the crossover distortion. Too much bias beyond a certain point buys you little additional linearity but increases quiescent current to where the amp runs much hotter than it should.

[dknightd]

So what kind of speakers are these - sometimes specs can be decieving. As long as you like them that is good enough for me. Just curious. . .

Some people will tell you all modern amps and preamps sound the same. I'm not convinced.
Lots of people have recommended high power "pro" amps to you. These amps have their place but I'm not convinced that place is in the home - of course I could be wrong. I've never tried a "pro" amp because most have cooling fans (fine if the amp is in a different room than the speakers, or, the speakers are playing loud), most take balanced input - a good idea if you plan long cable runs, but this is not usually a problem in a typical home. You can make or buy adapters to convert from typical home unbalanced connections to balanced connections, but this is an additional complication. Most of these "pro" amps are designed for loud PA or DJ operation, are designed to be cheap and deliver lots of watts. I'm not convinced this is what we want in our homes. If somebody has a spare "pro" amp I'd be happy to compare it to what I use - see below.
My suggestion is for speakers that are rated for 200w is to buy a 200w amp.
I bought a used Adcom 5500 on ebay for around $500. It is a well made amp that sounds good to me (it operates in class A mode most of the time - only on peaks does it go into class B). It has handy little lights that blink if the distortion gets above 1% (I think that is the number). I rarely blink those lights, but they are good indication it is time to turn it down a little.
Since your interest is in music, I'd suggest a 2 channel amp for your front speakers rated
around 200w (150-300 should be fine). Make sure what ever receiver you choose has preout connections, and 2 channel bypass.

[SteveCallas]

dk, where are you located? Perhaps we can schedule a gtg and have a blind listening test.

[dknightd]

Upstate NY

Edit: I'd be happy to supply food and drinks.

[Pyezahn]

FYI: the speakers I purchased are the new DCM TFE200's. I heard them at HE2006, and when I found them for $750/pair, it was a done deal.

Next question...

Whether or not I decide to use a receiver as a prepro or a dedicated prepro, I will significantly improve 2-channel audio with a dedicated amp for the main's - true?

If so, since adequate video is enough for me, it seems like the best choice for me is a good two channel amp for better music, coupled with a decent AVR for moderate surround results? Does that make sense?


By the way, is there a "substantial" difference in sound between a receiver and Prepro? For example, comparing a Rotel (5x125) / Outlaw 970, against a Rotel 1070 (2x130) / Marantz 7500 AVR, will the sound difference be severe? Or closer to negligible?

[tlf9999]

[QUOTE=Bob Lee (QSC)]In a class B amp, one transistor or bank of transistors handles the positive voltage swings, while another handles the negative swings. Bipolar transistors, however, require about 0.6 to 0.7 volts across the base-to-emitter junction in order to really start conducting, so a straight class B amp wouldn't track the signal accurately in the zone between about -0.7 to +0.7 volt.

Therefore, we have class AB, in which the transistors on both sides are biased so they are slightly on at quiescence. This smoothes the transition, and a little negative feedback then helps make it more nearly linear.[/QUOTE]

the classes are usually misused.

Class A conducts over the entire 360 degrees. Class B conducts exactly 180 degrees, and Class C conducts less than 180 degrees.

For most active devices, you will need to bias it a little to get it to conduct, 0.6v for bipolar or 3-4v for HEXFET.

So in a Class B amp, you just bias the output devices enough so that one bank starts to conduct the moment the other bank quits conducting.

Class AB is where you over bias the devices so that they conduct more than 180 degrees in a cycle. This will reduce crossover distortion. However, it creates another form of distortion called gm doubling: essentially the gain (mostly current gain) of the output stage gets doubled in the region when both devices are conducting.

As you can say, most people don't use those terms correctly and refer Class B (180 degree conduction) as Class AB.

[b curry]

Originally Posted by tlf9999
the classes are usually misused.

Class A conducts over the entire 360 degrees. Class B conducts exactly 180 degrees, and Class C conducts less than 180 degrees.

For most active devices, you will need to bias it a little to get it to conduct, 0.6v for bipolar or 3-4v for HEXFET.

So in a Class B amp, you just bias the output devices enough so that one bank starts to conduct the moment the other bank quits conducting.

Class AB is where you over bias the devices so that they conduct more than 180 degrees in a cycle. This will reduce crossover distortion. However, it creates another form of distortion called gm doubling: essentially the gain (mostly current gain) of the output stage gets doubled in the region when both devices are conducting.

As you can say, most people don't use those terms correctly and refer Class B (180 degree conduction) as Class AB.
What does class C have to do with this? Who is building class C audio amplifiers?

Let me ask you tlf9999, do you just read this stuff some place and then try to tell people what you know?

The reason I ask is, over at this thread on the AVS Forum http://www.avsforum.com/avs-vb/showthread.php?t=687042 you claim class B replaced class A?

Here is your quote:

Originally Posted by tlf9999
there are here to stay. digital amps are cheaper to manufacture, highly compact and efficient, can generate lots of power from a small package (high power density), are easier to interface with today's digital sources. Plus, they are good for marketing. My sense is that they are going to replace your typical Class B amps just as Class B amps replaced Class A amps, or transistors replaced tubes.

However, I do think there is a fad now with those devices. There is no inherent performance advantage to the class D amps, as Class B has no performance advantage over Class A. so you have an inrush of people trying to make a quick buck off the fad. My sense is that the bulk of the high-end class D amp makers will be gone in a few years and we will see a limited few manufacturers with big chunk of the market.

[Bob Lee (QSC)]

Fortunately, current gain "doubling" in a voltage source is largely irrelevant, as the real current gain will be determined by the load impedance.

[dknightd]

[QUOTE=Pyezahn]

Whether or not I decide to use a receiver as a prepro or a dedicated prepro, I will significantly improve 2-channel audio with a dedicated amp for the main's - true? [/QUOTE]
Maybe

[QUOTE=Pyezahn]If so, since adequate video is enough for me, it seems like the best choice for me is a good two channel amp for better music, coupled with a decent AVR for moderate surround results? Does that make sense?[/QUOTE]

Makes sense to me.
I think now you are at the point where you have to go out and listen and decide for yourself.

[sjoh]

[QUOTE=Bob Lee (QSC)]That would depend on at what output level the crossover distortion was measured. If the measurements are taken at the same output voltage, then neither amp will have more crossover distortion for a given output voltage, which wouldn't be unusual if they're of similar basic design.[/QUOTE]
Hello Bob,

Thanks for clearing that up.

Regards,
Sejin.

[Pyezahn]

I actually started listening and was rather disapointed. I thought the Rotel 1057 AVR was just what I needed - had a listen at a local dealer (mix/matched with B&W and BA speakers), and surprisingly I didn't like what I heard. Maybe it was those $4K B&W speakers I didn't like? I've listened to Rotel amps in prepro systems and loved the sound, so maybe my ears are truly in need of a prepro set-up? Have they started making "non-subjective" - absolute equipment yet? Gotta' get me one of those!

[tlf9999]

[QUOTE=Bob Lee (QSC)]Fortunately, current gain "doubling" in a voltage source is largely irrelevant, as the real current gain will be determined by the load impedance.[/QUOTE]

gm doubling is very relavent as every current gain is multiplied by the load impedance as be reflected through the feedback loop. What the feedback loop does is to maintain a constant overall gain for the amp. and if one part of the amp suddenly has higher gain, the feedback loop has to lower the gain in other parts of the system. this will be particularly an issue with high feedback amps without narrow open loop bandwidth.

This is more of an issue where CFP output stages.

[Bob Lee (QSC)]

[QUOTE=tlf9999]gm doubling is very relavent as every current gain is multiplied by the load impedance as be reflected through the feedback loop. What the feedback loop does is to maintain a constant overall gain for the amp. and if one part of the amp suddenly has higher gain, the feedback loop has to lower the gain in other parts of the system. this will be particularly an issue with high feedback amps without narrow open loop bandwidth.

This is more of an issue where CFP output stages.[/QUOTE]

However, in class AB amps we're talking about primarily emitter follower or source follower circuits--i.e.,voltage sources--so current gain is largely irrelevant, as long as it's not so low that the drivers current-starve.

[tlf9999]

let me try it one more time. This is concerning the open loop behavior of an amplifier. Think about the output node where the upper band and lower bank meet. think of a positive change in the base current for the upper bank. emitter current changes will be exactly the same, and in a Class B configuration, the lower bank remains switched off so the output current changes for the entire amp is the changes in output current from the upper bank.

so far so good.

In a Class AB configuration, the upper bank output is exactly the same. However, the lower bank is also conducting, and in this case, it sinks progressively less current. The end result is that on the margin, the output current from the node is higher, aka gm doubling.

As the output current goes through the load, the current gain for the output stage is suddenly higher in the region of Class AB conduction.

This works for both bipolar and mosfet output devices.

[ericgl]

In your example, I would be shocked if anyone could hear a difference.

[tlf9999]

I would agree most of us cann't hear gm doubling: I can dial my amps into class AB without any detectable deterioration in sound quality. I can also dial them into class C slightly without any detectable deterioration in sound quality.

I can only tell when an amp runs deep in class C at very low levels (like for headphones) that under bias becomes quite audiable. cross-over distortion, even in deep class C, can be hard to detect at high volume.

[edster922]

[QUOTE=Pyezahn]By the way, is there a "substantial" difference in sound between a receiver and Prepro? For example, comparing a Rotel (5x125) / Outlaw 970, against a Rotel 1070 (2x130) / Marantz 7500 AVR, will the sound difference be severe? Or closer to negligible?[/QUOTE]

I used to have a Marantz 5400 and when I added some NAD separates to power the mains, the improvement was drastic.

I also experimented by hooking up the Marantz directly to the NAD amp without the pre-amp, and found that 2-channel music was undoubtedly sweeter with the pre-amp in play. Also music was much better with the CDP hooked up to the pre-amp with analog connections than going through the AVR with a digital connection.

Unless your center and surrounds are difficult loads (4 ohms, under 88db sensitivity) I would suggest going cheap on the receiver and then buying a good 2-channel pre-amp and amp and (if you don't have one already) a good dedicated CDP. I've always found that for most normal 8 ohm speakers, you really don't need anything special to do HT, a basic $400-500 AVR is fine unless you absolutely cannot live without the extra bells and whistles. For HT, save your money for a really good subwoofer if you enjoy a lot of action/thriller flicks.

It's 2-channel music that really demands quality and subtlety from your gear.

An amazing bargain right now for the AVR would be the HK 635, $550 shipped from jr.com --- list price was $1300 which puts it right in the same class as those other AVRs you are looking at.

[Bob Lee (QSC)]

[QUOTE=tlf9999]let me try it one more time. This is concerning the open loop behavior of an amplifier. Think about the output node where the upper band and lower bank meet. think of a positive change in the base current for the upper bank. emitter current changes will be exactly the same, and in a Class B configuration, the lower bank remains switched off so the output current changes for the entire amp is the changes in output current from the upper bank.

so far so good.

In a Class AB configuration, the upper bank output is exactly the same. However, the lower bank is also conducting, and in this case, it sinks progressively less current. The end result is that on the margin, the output current from the node is higher, aka gm doubling.

As the output current goes through the load, the current gain for the output stage is suddenly higher in the region of Class AB conduction.

This works for both bipolar and mosfet output devices.[/QUOTE]

However, it is irrelevant.

The large-signal open-loop voltage gain of an emitter follower is just slightly less than 1, depending on the current gain; the higher the gain, the closer it is to 1. And remember, the emitter follower is typically being driven by a signal voltage, not a signal from a constant-current source.

At lower Vbe, the transistor's current gain diminishes. After all, a transistor doesn't just suddenly turn on when Vbe reaches 0.6 volt and become linear after that. Instead, it conducts slightly at Vbe well below that, and there is a knee in the transconductance curve at about 0.6 volts, and the curve becomes reasonably linear at about 0.7 volt. That's why biasing to a slight overlap of the transistors' conductance angles is necessary to decrease crossover distortion, and typically we use compensating diodes and a nominal amount of emitter degeneration to get reasonably close to this point; a trimpot then allows more precise setting.

So a doubling of an already diminished small-signal ß in the output transistors is not a bad thing, in fact it'll help bring the complementary-pair emitter follower's gain closer to 1. The only thing it may influence is soimewhat increasing the input impedance of the emitter follower, which is not a bad thing.

[Pyezahn]

Edster - thanks for message - it's those "life experiences" I appreciate most - theory is still theory, not matter which way you slice it.

I happen to love the Rotel sound, I found a used/mint 1075 (5 x 130), the price was great -so I snapped it up. Now that that decision has been made, I need to figure out where I go from there. I'm thinking with an Outlaw 990, I'd be set up fairly well. In 6 months I may be able to get one used for $700 or $800, which would make my budget smile. I don't know much about processor's, I'll be doing some research to see what other options I may have, but for my skimpy budget - the Outlaw is leading the pack. of course I could get a H/K 635 for less, but I'm guessing it wouldn't sound as good as a dedicated prepro? Or would it??? Since I'm only running 5.1, I could use the extra channels for another room, but not if I'm paying a significant price is sound quality. I don't have enough experience to know if the difference would be minimal or substantial?

[thylantyr]

[QUOTE=Pyezahn]I actually started listening and was rather disapointed.[/QUOTE]

Congrats! you are doing what many folks don't. Listening to systems to find
a winner.

I thought the Rotel 1057 AVR was just what I needed - had a listen at a local dealer (mix/matched with B&W and BA speakers), and surprisingly I didn't like what I heard. Maybe it was those $4K B&W speakers I didn't like?

Don't feel bad, I rarely find store speakers that satisfy me, hence I've been
DIY'ing. If you don't like what you hear, the #1 blame will be the speakers
followed by the 'lack of power'. Don't blame the preamp side.

You may be able to improve the perception of 'better' by increasing amp
power to drive the speakers better, it depends. To make matters worse,
power ratings may not be indicative of 'truth', but better brands have more
truth in their claims than mass market brands.

Keep auditioning until you figure it out.

PS. Why does a simple post to ask a simple question always end up in
a battle of electronic wits from the same posters on every thread ? I don't think the OP
cares about transistor biasing, crossover distortion, when the moon
turns green. :p

[mmiles]

http://www.crownaudio.com/amp_htm/designstools.htm

[Zues]

[QUOTE=Megalith]A pair of $1000 speakers is considered high-end?[/QUOTE]

High-end yes. High cost no.

[laststarfighter]

to the op,
mains ---check
5ch amp---check

it sounds like you want great 2ch sound and will be happy with good surround/av performance.

what I would do is pick out some matching speakers for the rest of the system,
like TFE60 for center/surround positions or a TFE60c for center, a sub of your choice.

now I would go with a surround pre/pro and hold off getting a dedicated 2ch preamp till you hear how your system sounds, and how the amp/mains perform together,
you may have to use a more robust amp for the mains so you would need something like a 300w x 2 amp(I did see that someone had a 400w/ch sunfire powering his and liked the sound)
later you can get your dream 2ch preamp for your music listening.
try to keep your options open for future upgrades

and if the pre/pro, Rotel 1075, DCM TFE200 sound like you want then you're laughing.

for a pre/pro, I'm an Anthem D2 fan, the D1 is the same thing cept that the D2 has a killer video abilities, and the D1 is upgradable to D2 specs.
also have a look at:
Classe SSP-300
Bryston SP2
Krell Showcase
Sunfire Theater Grand III
B&K’s Reference 50 S2

[Pyezahn]

Thanks for the suggestions. As far as those prepro's you listed...they are way out of my league. I need to be around a thousand dollars...whether it's a new/b-stock Outlaw 990 or a used "something or other", it will most likely be a prepro and not an AVR. *FYI: I did get the TFE60C-enter - the main's and center cost me 1000.00 to my door. I'm VERY happy with that purchase! The surround's will be easy to add later on.