In need of some Amplifier advice. Is therereally any point in it with my current setup?


Hello. I have posted in the past, but have since learned a little bit more from reading audio forums, and doing some research and have come to somewhat of a juncture. 

I figure I could "stair step" up on my own and enjoy the ride, or, ask those who have most likely been where i am before and skip a few steps =). 

My current setup consists of a Yamaha adventage-A3070 AV receiver (150wattsx8ohms 2chd), and 2 Polk LSIM707 towers. 

I've been looking at used Classe amps here on audiogon, or possibly a new parasound Halo A21 power aplifier,  and have thought about purchasing them. 

My question is, would my Yamaha advantage 3070 even be a sufficient pre-amp? It has pre-outs for all channels, and it also has an ess sabre DAC for my digital flac files. Or would using the Yamaha as a pre completely destroy the sound of the power amplifier? Essentially wasting $1,000-$3,000. 

My other question is pretty obvious. Should I trade up, just spend the $1,000-$3,000 on better set of speakers I've been eye balling like  the EMT-LFT8s, and stick with the Yamaha receiver's power for now. 

If it were you. What would you do? 


moskaudio
I would start with speakers. Listen to as many as you can. Once you find ones you like and determine they will sound good in your space now you will have the starting point for the rest of your gear. IMHO.
This largely depends on your end goal. Do you eventually want a full-blown system of separates...even considering monoblock amps? Do you definitely want to try the LFT8s? 

Your current AV receiver can probably manage with the low sensitivity of the LFT8s, but as with other planar speakers, they probably sound best with a high power amp. I like Yamaha products, but I'm not a huge fan of their AVRs. IME, their integrateds are in a whole other league when it comes to sound quality. While your AVR is not inexpensive, it still uses cheap, sheet stock heat sinks, a sure sign that they made sacrifices to the audio quality to make way for all the processing tech.   

The Halo A21 is a good amp. It will certainly power the LFT8s without breaking a sweat, but will probably give your current setup a decent boost in performance. I think you'd be ok using the Yamaha as a preamp. No, it won't likely perform as well as a standalone $2K unit, but I believe the amp section is where most AVRs skimp. By going with a new amp, you might manage to bypass the weakest link in your current chain, while preparing your system for a future speaker upgrade.

As for the LFT8s, I haven't heard them, but I wouldn't be surprised if their performance far exceeds the Polks, even when driven by an AVR. Upgrading the speakers may yield the greatest short-term ROI, as long as you listen at moderate volumes. 
@helomech I kind of assumed the power coming out of the Yamaha was  pretty meh and that as a pre it would probably be....decent. 

I'm thinking the Halo 21 or comparable would probably be the most logical first step, since I would need to acquire one eventually regardless. 

I'm not really going for a full blown system of separates. I have looked into two mono blocks as opposed to a two channel amp. 

But all this being said, Eminent tech does offer a 30 day trial for the LFT8s. But I know once I purchase them I'd have a hard time sending them back ;). 

I may just up my budget (which I can do), and go with both hah! 


Hey Mosk, where are you located?

I'm quite familiar with the Polk series and can say if you stick with that, the Halo A21 would be excellent.  The Yamaha will always have its flavor added to the sound, but adding the amp will still yield some major gains. The LSiM are some solid speakers and a far cry from what Polk is known for.  With that said, at their retail price, there are/were better options IMO.

Is this a home theater, 2 channel, or multi-purpose system?  If you went with the EMT, would you have room to actually get them off the back wall several feet? 
Take it one step at a time.  Get the Classe, Parasound or another higher end amp and use the Yamaha for it's preamp (realizing that's most likely the weak link) and see how you like it with your speakers.  I would then look to a higher end preamp, possibly tube preamp.  (I know very little about 7.1 surround since I'm a 2 channel person).  Once you change preamps, then see how much you like your current Polk tower speakers.  If the rest of your speakers are all Polk in your surround sound, then the LFT8's might not match your other speakers, so make one change at a time and give yourself time to get used to the change you made.
But yes, the Polk's mid range is fairly weak. When playing piano tracks and solo acoustic guitar tracks, it's quite apparent that they are lacking. 
@audiothesis, Oh don't worry. I acquired 2 new polk LSIM707s, 2 new polk 703s, a polk lsi706c, AND a new Yamaha adventage 3070a receiver for $2,800 on a deal earlier this year from Adorama. 

I know they definitely aren't worth their MSRP and wouldn't pay anything close to it. 

I use the 703s in my office with a rotel receiver. the 706c is still sitting in its box new, I will probably sell it as I don't have an interest in 5.1 or 7.1 audio. 

And yes, My living room is roughly 20'x18'. I've got plenty of space for positioning. 
If you can drive to Dallas, TX. , there is a Vandersteen dealer.
As 2psyop posted, try and audition as many speakers as you can. Once you find a 'sound' that sings to you, then you can start making decisions on the rest of the equipment.
Yamaha, if I recall, is a fairly neutral sounding amp. So, with 150 wpc, I think you have enough power for most speakers on the market.
B
I sent you a PM through the marketplace.  I'm in Arlington, TX, so not too far away.  I've got some ideas/advice, but I have many questions that would simply be easier via phone.
gdnrbob - its less about the power and more about control and noise floor.  IMO no receiver should ever be at the helm of a 2 channel system, though I completely understand why it is in this situation and can't fault it at all.  The package was a stellar deal.
@audiothesis I got your PM and we will talk soon. 

And normally no, that definitely wouldn't be at the helm of a system but at that package price, it was a no brainer for the time being! 
and @gdnrbob I agree. I do need to take some time and make a road trip to Dallas one weekend to audition tons, and tons, and tons, of different speakers that simply aren't available in my area to hear. 
@OP.You will be on the road to enlightenment.
And, don't let any dealer pressure you. You are on a quest to find a speaker that sings to you. Don't worry about related equipment until you find what you like.
When you do find something, let us know. 
We have all been through this and know how daunting it can be, but once you get your priorities, it all smooths out.
Bob
I have normally asked of anyone looking to upgrade their system, what is it that's lacking ?, what do you want more of ?, what do you not like about the system ?, before I make any recommendations. Have room acoustics been dealt with ? Have you upgraded cables ?. Is your source ( digital flac files ) good enough. You say piano and guitar is weak in the midrange. Have you tried an audiophile recording ( such as a Sheffield Lab, Reference Recording, Chesky, or GRP ( which is just a few of many excellently recorded labels ) ? Or listened to any Diana Krall, or Patricia Barber, etc. These are the types of recordings that will tax your system to do it's thing, to bring out the best, and show the worst. Guitar and piano, in many instances, are not miked properly in the mix, but female vocal is generally better to judge ( ime ). I am very source oriented, as you might tell. Just trying to help, as is everyone else. Enjoy !

The ET (Eminent Technology) LFT-8b does indeed far exceed the sound quality of any Polk I've ever heard (they're all over SoCal). It's good enough to lead VPI's Harry Weisfeld to proclaim the speaker to have the best midrange of any speaker he has ever heard.

A post above stated as fact that the ET needs a lot of power, which is an overstatement. It's sensitivity spec may lead one to form that presumption, but in practice is not particularly true. The LFT-8b does not require the power the other magnetic-planar speaker, the Magneplanar, does, for instance. I have both ET's and Maggies, and they are as different as they are similar. The LFT-8b is an easy 8 ohm load, your 15ow/ch amp will be fine until you can do better. The ET can even be run with a modestly-powered tube amp, as I do (100w/ch), which is not true of Maggies.

I don't doubt that bdp, but mrdecibel's points are just some of the questions I wanted to ask.  While the ET might sound better with proper placement, without the right space/setup abilities, you're going to get worse sound.

Yup audiothesis, it’s all good! Newer enthusiasts are commonly scared off by warnings from more experienced ones, causing them to over-think things. That commonly involves the amplifier/loudspeaker pairing. But anyone contemplating ANY planar should understand they MUST have space behind them---the more the better, but hopefully at least five feet. Three is commonly quoted, but that ignores the 10ms "rule": the rear wave of a planar speaker needs to reach the listeners ears at least 10ms after the sound from the speaker’s front wave. Sound travels at approximately 1’/ms, so 5’ to the wall behind the speakers and 5’ back to the plane of the speakers creates the required 10ms delay. The ear/brain can then process the sounds as separate, rather than the rear wave as a smearing of the front wave.

moskaudio, do you have the 5’? If not, the ET, or any other planar, is probably not appropriate for your room.

I'm not familiar with the Polk (or ET) speakers, but I totally agree with gdnrbob; put your money into speakers first. Then look at amps, pre-amps, etc. And yes, as he says, look for the speakers that 'sing' to you.

You're at the beginning of a search that should be a lot of fun. Enjoy!!

Gasbose


To answer one of your initial questions, if 2-channel is at all important to you the receiver needs to go.  All of it.  Forever.  End of story.  Then, as others have said, find the speakers that really blow you away and then find the power amp and preamplifier (or a good stereo integrated) that work best with them.  When auditioning speakers don't overthink it and just let them come to you.  When you hear the right ones you'll know because you'll stop thinking about individual aspects of sound (or other speakers) and just be thrilled with every part of what you're hearing.  Last piece of advice -- do NOT underestimate the role of the preamplifier in the ultimate performance of your system.  It is at least as (if not more) important as an amp.  Take your time and enjoy the journey. 

@soix  Thank you for the advice. I doubt i will really get rid of the receiver since i do use it for my 4k TV for various video sources, but i certainly won't be using it to power my 2-channel setup by the time I am finished. The polks however will most likely be sold/traded hah. 

@bdp24 I have plenty of space. At the moment my polk towers are spaced about 7-8' apart (The seem to sound the best to me at this spacing. All vocals and mids still sound centered when they are supposed to be). I have more than 16' of space to play with horizontally and more than 2' to play with in depth from the wall. I currently sit about 14' away from the speakers themselves. 
@mrdecibel  i have listened to many audiophile quality recordings to get a good idea of what the polks can do. I've listened to some remastered MQA 32bit pink floyd tracks, some MQA 32bit Daniel Barenboim pieces, along with a few MQA tracks from various female vocalists. Diana Krall being one of them. 

Overall for their MSRP and what i paid for I'm incredibly impressed. The only real basis I have for comparison are inifity r.s. 2.5 tower speakers with the 10" subs and 4 electrostats per tower. Which needless to say, blow the polks out of the water in the mid range and vocal area. 


@mrdecibel Unfortunately the infinity's belong to my father =P. He's had them since the 80s. Until recently however they had just been collecting dust until I connected them up with an older rotel integrated amp and a decent CD player. He didn't realize what he had =)
moskaudio
The only real basis I have for comparison are inifity r.s. 2.5 tower speakers with the 10" subs and 4 electrostats per tower. Which needless to say, blow the polks out of the water in the mid range and vocal area.
That is one sweet speaker system. Watkins woofer and they sound great biamped. Those are magnetic planar drivers, btw, not electrostats.
Those Polk LSiM are actually good speakers and can take you pretty far on your journey - especially for what you paid.  My favorite is the 703.  While its technically not a 'correct' speaker, its a blast to listen to.  I've almost jumped on a pair about a dozen times, but I've managed to stay away.  Honestly, the 707 is my least favorite but your room might be a good place for them. I always felt that line needed a 20-25% reduction in MSRP to really get competitive.  $4,000 for the 707 was just too much money as you start competing with diamond tweeters and the like at that point.

Those adorama packages are impossible to beat for the money, unless you catch a unicorn on the used market.

Make it down to Dallas like someone mentioned above.  Come visit my 'shop' and a few other dealers.  We have a few really good ones down here that I can recommend.  Like I told you in the PM: I'm an enthusiast first and a dealer second.  I want to see you get where you want to go and help you any way I can.
I’ve been where you are. I had a denon 60WPC old 5.1 receiver. One day I splurged $900 on an open box dynaudio center channel and pair of dynaudio audience 50 bookshelfs. I was smitten--THIS is amazing sound, cannot get any better. My all-in stereo was about $1100 and I couldn’t be happier. I’m on a budget, the halo is a dream amp for me I’ve always meddled in mid-high end... now I have a parasound 2125 amp, hareth p3esr speakers, a technics turntable with Pickering cartridge, NAD CD player..the hobby bites you quick. However, my entire setup is only about $5,000 used prices (I only buy used). This setup sounds better than that first one. A dedicated 2 ch amp kills a 60WPC home theater reciever. But I don’t believe I’ve ever experienced as much awe from a single upgrade as those dynaudio speakers on the underpowered HT reciever.

I got more satisfaction experimenting with multiple components in my budget than from spending it all on one piece.
Especially an amp. Amps DO color the sound slightly, but the differences after $400 are slight, from my small A/B tests (paramount, rotel, adcom, NAD). I’m not counting recievers, they color the sound a ton, but a good 2 channel amp will be a great upgrade and doesn’t have to cost as much as a halo.

As others said, speakers are where it counts... playing with different speakers, Maybe subs, Maybe a room mode PEQ like the miniDSP will have more noticible effects.

In my opinion your not stair stepping going from the Yamaha to a halo, your climbing a second story balcony to break in. I’d stick to stair stepping if it were me.

By the way, I had a Yamaha avantage reciever and thought it was bright/harsh. Not a good match with dynaudio. If it were me I would keep the Yamaha for movies and use a passive switch like the schiit sys to bypass the Yamaha (or build a dedicated 2 ch system) when listening to music. For HT you want boom and dsp, for music I only want CD, amp, and speakers. A passive preamp keeps the ’coloring’ of a reciever out and a good used $400-600 amp is plenty. Im a huge fan of using passive preamps, input selectors, and even speaker selectors to have physical control over what a reciever tries to do in DSP.

My point is, having been where you are i wouldn’t jump to a halo yet. But I would find a good, not too old brand name amp for $400-$600 (parasound, emotiva, rotel, NAD)... even more important is to pick speakers first.. some amps mate well with some speakers and horrible with others.


I think you should stick with the Yamaha for now and for quite a while. Amplifiers should not make much of a sonic difference, and by and large they don't. AV receivers are not ideal, but a recent one from a decent brand like Yamaha should not be a serious issue, and the power output should be enough.
The speakers and their interaction with the room are what really makes the sound of a system, and good speakers are expensive. I am not sure what your budget is, but you may have to spend more than you thought you needed. In a room like yours, how about the Harbeth SHL5+ on their own or their M30.1 augmented with a pair of small subwoofers? Both options are expensive but worth every penny. They are also an easy load, so your Yamaha should be fine with them. As an AV receiver the Yamaha will also have the advantage of room eq of one kind or another so you will not need to spend money on that. If good speakers are beyond your current budget, just wait and save. You don't have a bad system right now.
moskaudio,

I’m not sure if you are aware, but there is a great dealer right there in Moore, OK where you can listen to some speakers. Great guy to work with. I’m sending you a private message. I agree with others here that, as an actual transducer, different speakers will make the biggest difference in the overall sound that you will hear.

I, like you, always wondered if I could improve the two channel sound quality of my receiver by adding a separate amp. I have paired separate amps with several receivers, including a Yamaha RX-V1800, Onkyo TX-NR 809, and Denon AVR-X5200. I always like to get receivers that are in the upper middle of the manufacturer’s range, as I do believe they use a bit better components than their "el cheapo" models, but more importantly, because they offer pre-outs. The amps I have used in conjunction with my receivers include a McCormack DNA-1 Deluxe rev. A, Sherbourn 5/1500a, and Krell FPB 400cx.

Now, my family room system is where I have the newest AVR, which is the Denon. The amp I currently have paired with the Denon is a Krell FPB 400cx, which is a class A power amp. I must say, there is something nice about the sound I am now getting with the addition of the Krell. But it is expensive and runs hot as Hades.

If you do decide to add a separate amp, you will need a set of interconnects and I recommend a quality set.

If it were me, what would I do? Decide what I want....and get just that. If you think you might like the EMT speaker, have a listen to see if you do. But fair warning, those are good speakers not home theater speakers. You may not like the sound from them until you hear them AND you may not like the sound from them if you don’t match them with good hi-fi equipment. They probably need lots of current and clean power and signal to sound their best. Hear them with well matched power amp and source. If you use a HT preamp and amp with speakers like these, you may only enjoy 1/2 of what they could sound like. By mixing, selling, trying again audio equipment many audio nuts end up wasting money, having fun too, but still wasting money.
BTW I had wasted about $6-10k on audio equipment before I knew what I was doing and what I wanted. Big mistake because I don’t make Wall Street kind of money!
Driving a good pair of speakers with any part of an AVR if you care about 2-channel is just silly.  SILLY.  And, as you'll see below, completely unnecessary.  It's like buying a Ferrari and putting Sears Roadhandlers on it.  Sure, you can do it and you still might get some enjoyment from it, but most of the performance you paid a lot for will go unrealized.  You can patch in a good amp through your AVR preouts and that'd be like replacing the rear tires.  Yup, you get to enjoy more of the performance, but you're still leaving a crapload of enjoyment on the table.  Not until you replace the entire AVR in the 2-channel chain with a good stereo amp and pre (and assuming you have a decent source of course) will you get full enjoyment out of good speakers.  And you CAN replace both while leaving the AVR in for TV/video purposes.  Here's how...

Since you have preouts on your AVR, you simply take the front L/R preouts and route them to an unused input -- let's call it "video" -- on the dedicated stereo pre (or its HT bypass if it has one) and connect the stereo pre to the stereo amp as usual, which is then obviously connected to the speakers.  (Same can be done -- even easier and likely more cost effectively -- with an integrated stereo amp). Your high quality 2-channel source goes directly into another input on the stereo preamp or integrated -- let's call that input "CD" -- and you're basically done, and now the AVR is completely removed from the system for more serious 2-channel listening.  When you want to listen to good stereo you choose the "CD" input on the stereo pre, and when you want to watch TV/video you choose the "video" input and that's it.  The only thing is that if the stereo preamp doesn't have a HT bypass input you need to set a reference volume level on the stereo pre that is balanced correctly with the AVR.  I used to just use the 12:00 position on the pre as it's easy to set quickly and fairly accurately. 

Lots of us have done this here with great success, and trust me it's much easier in practice than it looks here in writing.  You'll now have a pure, high quality 2-channel system seamlessly embedded within your video system.  Best of both worlds!  And you can do it in stages as funds allow and fully appreciate the significant upgrade each stage brings.  Of course then you'll want to upgrade your speakers again and on it goes...
The bad news is you need to start over. The good news is you need to start over.

+1 @soix 

if 2-channel is at all important to you the receiver needs to go.  All of it.  Forever.  End of story.

@soix , would it not be better to come out of a tape out ( record out ), instead of a preout, avoiding another gain stage / volume control, or, am I just showing my old age ? 
I guess that would be correct if you're only running front L/R speakers and don't need to balance with center, surrounds, etc. 

I agree with david_ten, +2 soix, good post. A receiver is "not" equal to a good quality amplifier if high quality 2 channel stereo is the objective. Anyone who suggests that amplifiers make no or minimal difference is offering poor advice IMO . Speakers are important, so is the quality of amplification. Not an area to cut corners.
Charles
@soix  @charles1dad 

I was inclined to agree from the beginning with essentially starting over. And  in a post above i mentioned the probability of buying a different set of speakers and an amp. Adding a matching preamp to the setup will be just fine. 

As far as the preouts and loop in/loop outs go I have a fairly good understanding of it and that won't be an issue. 

The other thing I've thought about, which @2psyop  mentioned, is, speakers for different purposes. 

The Yamaha Adventage 3070A has so many various decoding modes for home theater and surround type setups its ridiculous. small/large center presence for L/R. small/large surround presence for L/R. Ref SUBw presence for L/R, that I really dont need a full surround system with the Polk 707s. The Ref SUBw presence is enough to shake my house with the 707s. and the small surround and center on the polk 707s also do the job. They actually do make it sound like most of the surround coded audio is coming directly from the left or right of me. So overall, I'm happy with this for home theater. I'd add the 706 center or the 703s for surround but this would obviously sap too much power and strain the receiver and probably just weaken the bass and overall system and I would need to get it it's own 5 channel amp. Which I don't want to do. 

I may keep the 707s and AVR for this home theater setup.

When I want to listen to music, simply move some a few interconnects and banana plugs around and hello new music 2.0 setup!

I really appreciate everyone's input and posts on this. And I think I've learned there is no need to try and cheat or cheapen my way around it like @soix mentioned with an AVR preamp setup baha. 

I will be trialing new speakers, and then looking into pairing a pre amp/amp after finding a pair of speakers that sing to me. Maybe it'll be harbeths, maybe it'll be EMTs, who knows. Let the fun begin!
@mtrot  I actually was not aware. I don't think I got your message. I know there is a company called audio dimensions in Oklahoma city but their ratings are very poor, and I have a few friends that have been there and I hear it's not a company you want to visit or work with. They essentially push one set of home theater speakers on you with amps they need to sell and don't really let you demo much. 
Hmmm.  @moskaudio, you do realize the setup I described above allows you to keep the AVR and pure stereo components (amp and preamp) completely separate within the same system without having to swap any interconnects or cables, right?  That's the whole point of this.  If you're having to swap wires to switch between stereo and HT there's something amiss here.  All that's necessary in the setup I described is to change the input on the stereo preamp to switch between the stereo and HT, and you'd be using your "good" speakers (when you get them) for both stereo and HT.  No 707s required.  The AVR is completely out of the system for stereo and only involved when doing video related stuff -- nothing cheap about this at all.  Not sure I was clear on this point. 

@OP, that is definitely not a dealer you want to deal with.
If you can make some time available, take a day or weekend and contact a few dealers in Dallas. Make sure they can accommodate you (if they can't, scratch them). Tell them you are listening to find speakers you like and don't worry about details-like amps/pre/source. Just let your ears be the judge.
A good dealer will be happy to let you audition and not pressure you.
Bob
@ moskaudio

For the message I sent, you first have to go to the main Audiogon page and navigate to your name/profile box in the upper right corner, where there will be a drop down list of options.  Select "Dasboard", then "Inbox".  Then my message should appear.

Also, I agree with soix above that there is no need for switching cables; you just get a pre-amp or integrated amp with home theater bypass.  I am currently researching this and looking at various pre-amps and integrated amps. 
A HT bypass is nice but not necessary, so if the pre or integrated you really like doesn't have one it's not a big deal -- don't let that limit your choices.  Any spare line-level input will work fine. 

@soix  That does make sense. The banana plugs wouldn't need to go anywhere. and the audio input would simply go into the preamp along with the AVR output. *facepalms*
and yes @soix  I'm know I would need a pre/amp/dac or an integrated for that to work. Along with a new set of speakers. So like you said above, essentially starting over =)
@ moskaudio

What did you decide to do?  Have you listened to any speakers or amps?
I have listened to the Parasound Halo integrated, Peachtree nova 300 integrated, Rotel RA 1952 integrated, paired with my Polk LSIM707s. I know these aren't the greatest speakers, but, they are full range. 

As far as the integrated amps go, I like the Parasound Halo and Rotel over the Peachtree. 

The Peachtree seems more neutral and dynamically bland when compared to the Rotel and Halo. Honestly, I think my Yamaha 3070-AVR sounds better than the Peachtree and seems to almost have as much power. 

I like the punch and precise accuracy of the Rotel when listening to rock and most music made post 1990.

However, i prefer the parasound when listening to vocals like Norah Jones, solo piano, jazz, and classic rock.

The Rotel almost seems to take the classic out of...the classic. The best way I can explain it. When listening to The Who, Crosby stills and nash, and a few others everything feels forced, even when tonally adjusted, and to my ears it takes away from the classic feel and tries to bring them into the 90s. Some of this may be the polks, but I didn't have the same sense with the Parasound.

Also note that I was using Flacs and MQA files through the 3 integrated's DACs. I do not use turntables or SACD players.

Between the three I would pick the Parasound Halo hands down.  


I will be demoing some Focals, Martens, Rogue hybrid amps, and Harbeths soon. 
Nice!  I believe that the dealer in Moore that I sent you carries all of those.  In a little higher price range, the new Anthem STR integrated amp is getting nice reviews, and it also has home theater bypass, so that you can keep your Yamaha 3070 in action. 
Yeah I saw that integrated and have thought about it if I can find a place to demo it.  The Halo also has the bypass option. As does the rotel I believe.

The dealer you referred me to is whom I'm going to be demoing the speakers and rogue amps I mentioned with when we both find the time. 

Thanks! 
Just reading and catching up on this thread.  One comment I will make is I think your choice of Yamaha 3070 is a very good one.  I think the Yamaha is the most neutral and most natural sounding receiver without pushing any particular characteristic (for example, Anthem receivers tend to over-push high frequencies like a ribbon tweeter, Marantz receivers are to warm/slow losing resolution when everything sounds like mush).  However, every single receiver will be limited on the aamplifier section.  They ALL will have very limited size power supply and all will only have 2 output transistors per channel (one transistor for positive waveform and one transistor for negative side of waveforms).

adding an external amplifier will enable you to drive the speakers much better (even on easier 8 ohm speakers).  Amps will have massive power supplies, huge transformers, large capacitance such as 50,000uf to 100,000uf (compared to something like 2 x 6800uf of a typical receiver).  They will have anywhere between 6 and 12 output transistors per channel (the Parasound A21 has 8 transistors per channel).  You will have much more clarity, attack, slam, punch.  Adding an amplifier to your Yamaha 3070 can be a great first step.  That being said, the Yamaha will have conventional op amps in a clean sounding fashion.  I would be careful of amp choice and would stay away from ultra-clean stuff like typical Class D or Bryston type amps.  Look for a warmer or “Class A” type amp.  Parasound A21 is an excellent choice.  I’m sure there are others.  I believe the Parasound uses a fully discrete jfet input stage ran in Class A mode.

If if you were interested in Class D, only 2 recommendations.  PS Audio Stellar Gain S300 with Class A input stage.  Or Nord One Up with Sparkos discrete Class A op amp input stage.

A comment on on the Parasound integrated.  It is a very nice integrated if you need all the features.  It is basically an A23 amp with a larger transformer and a P5 preamp put into a single chassis. It is very nice, but it is not an A21 amp!  The P5 preamp is okay, and is a great buy if you need all those featurs, but there definitely better choices.

i would say to start with something like a Parasound A21 with your Yamaha 3070.  You could always add a really nice preamp later and configure the system as a “hybrid HT/2-channel system”.

many have recommended to start with speakers.  Changing speakers can definitely have a significant impact on sound.  But the amplifier is also a very important piece and can really make any speaker “sing” much better.
If you really wanted an integrated, I would look at the Hegel. Like this H160:

http://www.audiocircle.com/index.php?topic=155723.0

It is pretty much the equivalent of the Parasound Integrated (but without phono preamp and sub crossover). Hegel also has limited analog inputs (1 rca, 1 XLR, 1 ht bypass). However I think the Built DAC is much better. The Parasound Integrated/P5 DAC is pretty much junk. I think it would be a better end result than the Parasound Integrated. There are more expensive integrated, of course.

The Hegel will be very nice, but personally I would rather go with A21 amp and a very nice preamp.

Here is the thing... if you try to upgrade your overall sound by getting better speakers and powering them with the Yamaha, they aren’t going to sound very good. If instead you upgrade to the Halo, you get an immediate improvement and can upgrade the preamp/dac later. 

And now the sweetner... if you buy the Halo preowned and decide a year from now to go a different direction, you will probably loose less than $150 on the resale as parasound halo holds its value!!