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Discussion Starter · #1 ·

Just bought a used Adcom 7700 off of CL, I think it opens up the soundstage and offers great dynamics so far. A couple of quick questions for you experts

 

1) Do different levels of AVR's offer "better" pre-outs than others? (brand/flagships)

2) I hear a slight noise from the speakers now only when I put my ear up to the tweeter....is this what's called noise floor? Any way to reduce the noise?

 

Thanks
 

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Turn everything off, and disconnect the Yamaha from the Adcom.  Then turn on the Adcom.  If you hear the noise, it is the noise floor of the Adcom.  You could try having it repaired, but it may be that it is operating as designed.  If you do not hear the noise, then ask some more.

 

As for differences in preamps, there are measurable differences in which higher models often are better.  But they can measure things that you cannot hear, and so in practice, it is usually unimportant.  However, higher end models often have more features, and those can be useful.

 

 

Also, you are not going to like this, but most likely the opening up of the soundstage is probably the placebo effect.  You might be interested in this video:

 

http://www.youtube.com/watch?v=BYTlN6wjcvQ
 

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Discussion Starter · #3 ·

Long video, I'll have to watch it later unless you can tell me what minute of the presentation I need to go to. I am getting new cables (emotive x-series rca) tomorrow and I'll try out your method. Thanks for the heads up. Hopefully that will cure the noise. It's not really audible unless I put my ear up to the speakers. Placebo effect huh, well, I can see why you would say that. I can't really explain the differences (like cigars: peppery, leathery etc) but something is there. The voices seem like they are warmer, dynamics. My receiver is pretty decent being in the Aventage family. Only reason I went with an external amp is it was a great deal and worth getting my feet wet with external amps. ($425)
 

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Yes, it is long.  Just watch the first 5 minutes, and only watch more if you are interested.

 

And yes, your Yamaha is a good one.  It should be able to drive your Klipsch speakers to levels that can cause hearing loss, so you very likely do not need any more power.  And the Adcom is not that much more powerful.  It takes a doubling of power to increase volume by only 3dB.
 

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Quote:
Originally Posted by asharris7  /t/1515829/adcom-gfa-7700-paired-with-yamaha-aventage-1030#post_24307115


Just bought a used Adcom 7700 off of CL, I think it opens up the soundstage and offers great dynamics so far. A couple of quick questions for you experts


1) Do different levels of AVR's offer "better" pre-outs than others? (brand/flagships)

2) I hear a slight noise from the speakers now only when I put my ear up to the tweeter....is this what's called noise floor? Any way to reduce the noise?


Thanks

1. What are you looking for "better" in terms of pre-outs. For the most part the 1030 has a very good pre-out.


2. I have a pretty similar setup. I have RX-V773 and a Adcom 7500. I hear a very faint noise at my tweeters also when I put my ear next to it. At listening positions it's un-noticeable. It's been a long time since I've shopped at the high end stores, however I seem to remember always hearing a little noise.


There is a little difference of power, as I'm guessing the Adcom will be 4-5 dB louder. As it takes 10dB to double the volume. However if you are going to play very loud then the Adcom is probably a better bet, Yamaha rates the 1030 at 165W a channel at 10k hz and 10% THD with 1 channel driven. The Adcom is rated at 175Wx5 at .06% THD continuous.


What is most important is which sound you like better, internal vs. your Adcom. I'm guessing you heard nothing when you connected to the A1030 and placed your ear next to the tweeter.
 

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Discussion Starter · #7 ·

You're correct, I didn't hear a noise with the Yamaha receiver. I wasn't looking for "best" really, just good, better comparison on the pre outs. No biggie, just a lot of misinformation out on the Net. May I ask why you have an Adcom? What improvements were you looking for? Can you notice any audible difference?  BTW, I liked both amps.....it's just that the high's 2-4k seem a little more warm and the peaks in movie soundtracks seem better. Hell, even my wife noticed a difference between to 2 amps on the Eagles Blu-ray and she did not even know I had the amp much less hooked it up yet. (yeah, I hide some purchases lol)
 

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Discussion Starter · #8 ·
I see you edited your last post. The adcom I have is 175 wpc x 5. The Yamaha all channels driven is probably around 45 wpc. But yes, you are right, if I want to play louder the adcom would be the best bet. I'll ask again, what was your perceived difference when you added the adcom amp?
 

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The reason I bought the Adcom is that the speakers I have are pretty challenging to drive. Most mid level receivers will have thermo issues driving it, and the my V773 is not even rated to drive them so I didn't try. My guess is that at low volumes it would be perfectly fine, but I did not setup my theater so I can listen to a movie at a whisper.
The Adcom replaced a NAD receiver which was driving the speakers fine. However I could not get a right balance of noise floor and volume using the 2 receivers together. I added the Yamaha receiver to the mix because my NAD was dated and did not have HDMI switching or could it decode the new formats. The DAC also went south, however the analog inputs and the amp section worked just fine. I've also always wanted a higher end amp, and found the 7500 at a price I could not refuse. I believe the noise you hear is a slight hiss at the tweeters. And it's only audible when your ear is very close?


For what I was doing I noticed a ton of improvement! My noise floor is totally gone. I have not had a chance to give it a good workout yet. I guess I was very lucky my wife mentioned that the Adcom looked very sleek with the rest of the equipment.


Enjoy your 7700!
 

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Quote:
Originally Posted by asharris7  /t/1515829/adcom-gfa-7700-paired-with-yamaha-aventage-1030#post_24308212


I see you edited your last post. The adcom I have is 175 wpc x 5. The Yamaha all channels driven is probably around 45 wpc. But yes, you are right, if I want to play louder the adcom would be the best bet. I'll ask again, what was your perceived difference when you added the adcom amp?

Ahh yea, I could not remember the exact output so I took a guess. I do know one thing for sure when I give it a good listen I should have much better mid bass response. I don't have a sub, but my mains have a 10" woofer (PSB Stratus Gold I) and rated to 31 Hz and with the dampening factor of the Adcom the bass should get really tight.


I've also edited my original post to you as not to contribute to the mis-information on the net.
 

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I think the 1030 can actually do more that 45 rms. Thats about what the 773 does. But if it was at 45 then there would be about a 6dB increase which is not quite double as it takea 10dB to double the volume.
 

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Quote:
Originally Posted by asharris7  /t/1515829/adcom-gfa-7700-paired-with-yamaha-aventage-1030/0_100#post_24309479


Jack, I don't understand why you say the adcom is not that much more powerful? 175 rms vs around 45.
 

The long answer is here:

 

http://www.audioholics.com/audio-amplifier/the-all-channels-driven-acd-amplifier-test

 

You will need to click through to read the several page article.  The short answer is that the "all channels driven" test is not representative of actual use of audio gear.  The Yamaha is perfectly capable of putting out more than its rated 110 watts into a channel or two as needed.  Yamaha wisely designed the receiver for actual use, not for passing some test that some audiophiles imagine matters, but are mistaken about.

 

If the short answer does not seem enough, read the article at the link above.
 

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Discussion Starter · #14 ·
Makes sense. However, he did say that amps are needed to cover frequency response curves where the impedance is halved. Hell, for $425 in like new condition, I feel like it was a good purchase. Btw, hooked up my new emotiva xrca cables at lunch. Didn't cure the noise. It seems my amp and my APC H15 don't like each other because when I turned of the APC, the hum went away and the amp was still on...gonna mess with it some more tonight. Might have to hook amp up to a separate outlet
 

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Discussion Starter · #15 ·

Update! Switched power outlets and ZERO NOISE! Now I am a happy camper. Jack, I take it you do not own any external amps?
 

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Quote:
Originally Posted by asharris7  /t/1515829/adcom-gfa-7700-paired-with-yamaha-aventage-1030/0_100#post_24311879

 

Update! Switched power outlets and ZERO NOISE! Now I am a happy camper. Jack, I take it you do not own any external amps?
 

I am currently using two power amps.  One is used for my main two channel system, which drives my 3 ohm Apogee Stage speakers.  In my home theater, I use a power amp to drive my pair of unpowered SVS CS-Ultra subwoofers.  But I am not using any for driving my main channel home theater speakers.  They are not a difficult impedance, and are not a problem for any decent amplifier to handle.  So there is no point in using external amplifiers with them.  Additionally, I used to use a receiver with them that was about half as powerful as my current one, and it could drive my speakers to volumes I found painful, with crystal clarity.  So, really, there is no point in using an external amplifier with them.

 

I would not want to use my home theater receiver to drive my Apogee speakers to as loud as I sometimes play them, as it might cause some problems.  But of course, it isn't rated for use with 3 ohm speakers.  If my Apogee speakers were a part of my home theater, then I would use an external amplifier for them.  In cases where separate amplifiers are needed, then I use them.  I advise other people to do likewise; if they are needed, then they should be used, but if they are not needed, it is better to save one's money or buy something else instead.  
 

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Quote:
Originally Posted by asharris7  /t/1515829/adcom-gfa-7700-paired-with-yamaha-aventage-1030/0_100#post_24312037

 

So in reality, you think I wasted $425? No big deal if you think I did.
 

You should not ask questions when you don't want to know the answer.
 

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Quote:
Originally Posted by asharris7  /t/1515829/adcom-gfa-7700-paired-with-yamaha-aventage-1030#post_24312037


So in reality, you think I wasted $425? No big deal if you think I did.

What's most important is what you think. If you're happy with your purchase then good enough.


So a different outlet eliminated the noise? Are you still using your APC? I do have my amp plugged into a surge protector strip thing. I'll have to try a different outlet and see if that makes a difference. Is the outlet on the same breaker? Was your noise a hum or a hiss? It's probably better you don't use the APC as that's rated for 1500W and your amp is north of 1600W at max I believe.


The Amp will make the most difference if your going to really turn things up. But for the most part the 1030 should have no problems driving 8 ohm speakers. The 1030 may have some audible noise when cranked up according the results on paper, however in the real world one may not notice. Are you planning on playing things loud?
 
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