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post #61 of 242 Old 01-19-2011, 07:11 PM - Thread Starter
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Quote:
Originally Posted by jsil View Post

I'm looking at adding an amp to my Pioneer 1120 and was wondering about the SQ. Will the amp effect the SQ or receiver will have the most effect with SQ.

Repost this outside this thread. You will start a nice little war.

Please keep posts here related to comments/suggestions/criticisms of this FAQ!


Why?

Because it will keep this thread cleaner AND you will get more opinions. And if for some reason you are posting here because you want my comments, you will probably notice from my post count I post a lot - there's a good chance I will answer any questions in the amp/receiver forum if I know something about the topic (or think I do.)

"But this one goes up to 11"
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post #62 of 242 Old 01-27-2011, 08:58 PM
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Quote:
Originally Posted by Knd View Post
Great help thanks. What about a FAQ concerning pre-amps, what they are, pro's con's etc?

Just a thought.
Quote:
Originally Posted by MichaelJHuman View Post
Stereo pre amps or AV processors? There's not much I could add about AV processors that I did not cover in the AVR FAQ.

Stereo pre amps are simple pieces of equipment with a source selector and a volume control. I am not sure what I could say about that...
I was considering the same question about pre amps. Unless I'm more ignorant on the subject than I already suspect, most all discussions I've read focus on the power amp side where it seems the most often specs are considered (except THD. Looking at various separates specs I'm not sure if THD belongs to amps or preamps). But I've dropped in on other conversations that talk about how the pre amp section might influence SQ. If the power amp only reproduces what the preamp feeds it I can understand how important the pre amp might be. Thanks.
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post #63 of 242 Old 01-28-2011, 09:04 PM - Thread Starter
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Pre amps have THD and noise just like power amps.

Before there was digital, vinyl was popular. Because vinyl requires a lot of gain AND something called RIAA eq (to compensate for deficiencies,) a lot of people felt pre amps were very important.

When line level became more common than phono level, in some ways, it could be argued that all you really needed was source selection and attenuation (a volume control.) Gain would not necessarily be needed.

With digital, you have four basic signal blocks - DSP, Digital to analog conversion,
usually a buffer stage, and volume.

It seems common that the DAC outputs the signal as changes in current, and op amps coupled to the DAC output voltage.

Some people worry about DACs. You would think they have been perfected, and they have excellent specs.

Some people seem to think the op amps coupled to the DAC are important. They never seem to explain how they know this.

The volume control chip is op amp based in designs I have seen. Certainly is has the potential to influence the sound.

When pre amps stages are measured, they usually have REALLY low THD+N. And VERY flat frequency response. Some could argue it's audiophile nonsense that they have much if any affect on the sound. You have to decide for yourself.

"But this one goes up to 11"
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post #64 of 242 Old 01-28-2011, 09:55 PM
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Quote:
Originally Posted by MichaelJHuman View Post

Pre amps have THD and noise just like power amps.

Before there was digital, vinyl was popular. Because vinyl requires a lot of gain AND something called RIAA eq (to compensate for deficiencies,) a lot of people felt pre amps were very important.

When line level became more common the phono level, in some ways, it could be argued that all you really needed was source selection and attenuation (a volume control.) Gain would not necessarily be needed.

With digital, you have four basic signal blocks - DSP, Digital to analog conversion,
usually a buffer stage, and volume.

It seems common that the DAC outputs the signal as changes in current, and op amps coupled to the DAC output voltage.

Some people worry about DACs. You would think they have been perfected, and they have excellent specs.

Some people seem to think the op amps coupled to the DAC are important. They never seem to explain how they know this.

The volume control chip is op amp based in designs I have seen. Certainly is has the potential to influence the sound.

When pre amps stages are measured, they usually have REALLY low THD+N. And VERY flat frequency response. Some could argue it's audiophile nonsense that they have much if any affect on the sound. You have to decide for yourself.

Man there is a lot to learn. Many thanks for the explanation. I guess there's really no substitute for listening.
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post #65 of 242 Old 02-03-2011, 02:49 PM
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Does anyone know if the EMO XPA-5 has:

Does the XPA-5 Amplifier contain high-quality circuitry in the power supplies to reject R.F, line spikes and other power-line problems in so that no power line conditioner is required, except to plug the AC line cord directly into the Wall Outlet?

Thanks
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post #66 of 242 Old 02-03-2011, 03:26 PM
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MichaelJHuman -- Very Nice POST, some reading here for tonight!! Hope the EMO XPA-5 will blow a hole in LOVERBOY's Red Pants - The Canuck Band, and should get me up to 118db per others, but set VolMAX on Denon to 0db for now -- Dennis
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post #67 of 242 Old 02-03-2011, 04:09 PM - Thread Starter
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Just remember your hearing is priceless

I personally know the results of irresponsible listening levels, having hearing damage and occasional ringing in my ears.

"But this one goes up to 11"
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post #68 of 242 Old 02-04-2011, 09:22 AM
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Yes, me to with a Jack Hammer inside a 5 yd. concrete drum with no earmuffs... caused me to have a 13KHz. Notch filter attenuation. In fact, when my Casio watch sounds it's alarm right on my wrist I can not hear it at all unless I put my ear right up to it. Still waiting on the XPA-5 here, but EMO called the other day for $$. Hopefully, I made the right decision in buying it and don't have buyers remorse.

Going to use these cables from MonoPrice for interconnects between Denon and XPA-5:

3ft High-quality Coaxial Audio/Video RCA CL2 Rated Cable M/M RG6U 75ohm Gold connector (for S/PDIF, Digital Coax, Subwoofer & Composite Video)

THINK THESE WILL WORK OUT OK?
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post #69 of 242 Old 02-04-2011, 09:41 AM - Thread Starter
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I am the wrong guy to ask about cable, unless you like the 'wire' is 'wire' answer

"But this one goes up to 11"
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post #70 of 242 Old 02-04-2011, 02:41 PM
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Here is the newly released X Series Operation Manual from EMO on their X-Series Amps, since I guessed I complained so much about their User's Guide on the XPA-5 which stunk to high heaven.

http://emotiva.com/manuals/x_series.pdf
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post #71 of 242 Old 02-05-2011, 04:24 PM
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Here is a great article on Amp Measurement Techniques:

http://www.audioholics.com/education...ent-techniques

Enjoy!! Dennis
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post #72 of 242 Old 02-22-2011, 09:55 AM
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Quote:
Originally Posted by M Code View Post
The latest Class D solutions are excellent, and sonic ally they are superb.
Yet today still are many who are sceptical of their electrical performance.

I will recap for you a personal experience for this subject..
About 3 years back, I was asked by the president of a very large US based audio brand to organize an audio comparison demo of the latest Class D amplifiers vs. high quality Class A-B amplifiers. I took 4 of the latest Class D solutions (Ice, Zetex, Intersil, TI) and a high-end Class A-B amplifier of the client's brand. I level matched each driving a pair of well-known high-end loudspeakers that sold for about $6,000 and used a low-loss speaker relay switching system.

The listening panel was made up of the brand's golden-ears, their marketing guys and president, our objective was to compare each amplifier and our basic question was Which amplifier sounded the best?
Note that the listening panel did not know which amplifier was playing, after 3hours of playing these each member of the listening panel could not tell any difference between each amplifier.

The end-conclusion was that all of the latest Class D solutions are capable of delivering a high-quality, neutral, uncolored response, equal to a comparable, quality Class A-B amplifier. There remains some biases over the smaller footprint of the Class D solutions rather than massive heat sinks. But in this face-off there was no discernible audible differences.

Just my $0.02...
Great thread Michael!

M Code that sounds like a good test.
I did my own comparison to try out the D-Sonic MAGNUM 2500-7 (Cox 250x4) amp. I had a fried bring over is Outlaw 200Wx5 amp and also include my 10 year old Sunfire Cinema Grand Signature (400x5) amp. Of course, none of these rating a continous all channels driven.

We listened at moderate (peaks in the low 90DB range) and what I will call comforatable (in the low 80 DB range).

The Outlaw seemed to have the most impact, detail, and had great speed.
The D-Sonic also was detailed but seemed rolled off. It upper end I liked, but my friend and wife did not like it as well as the others.
The Sunfire was the least bright of all the amps, I got the impression that was not as fast (which is the best way I can think of describing it).

Where the D-Sonic really fell down was on the lower end. It did not provide the bass that the other amps had. The Sunfire had slightly more than the Outlaw. My speakers a Revel Salon's which are not very efficient (86 DB) and deliver bass down in the low 20hz range. Surprisingly, this was at relatively low playing levels. The impact was there but it did not sustain the bass as well as the others. I ended up returning it. I am no expert, but I did read some articles that indicated that these amps can suffer from phase issues which could explain the lack of bass that I was experiencing. I do not think it was defective because I tried three different sets of channels.

Since then, when I read a review, I also pay attention to the speakers used. Very often the speakers do not go much below 35Hz so I take that into account. Also, when I here: the bass was fast, tight, and not bloated, I take that as not much bass

I sold my Sunfire Cinema Grand Signature and bought a used Sunfire 7400 (400x7) amp and bi-amped my Revels since I had two extra channels. It couldn't hurt. I am very happy with the Sunfire.

I really wanted to love the ICE amp technology (and still do), but I would not buy one without a low risk in-house trial.

H-Class amps seem to provide the best of both worlds, low power and heat with the performance of an A/B amp.

- Rich

Oppo Beta Group

Oppo BDP-105D | Oppo HA-1 | Oppo PM-1 | Parasound A51 | Revel Salon, Voice, Studio | Velodyne HGS-15
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post #73 of 242 Old 02-22-2011, 04:51 PM - Thread Starter
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There are some pro amps using class H topology. I think some might also use switching power supplies. Which makes them efficient and light.

"But this one goes up to 11"
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post #74 of 242 Old 02-28-2011, 01:43 PM
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Hi.
I have to drive a pair of Paradigm Studio 100.
I have retired a first Carver M1.0t which was causing loud crackling sound on the right channel and replaced with its twin....which Is just al old (24 years).
An Anthem MCA20 or Anthem A2 has a signal to noise ratio of 120 db.
The Emotiva XPA-2 has a S/N ratio of 91 db at 1 watt and 110 db full power.
I use a Denon 4308 as a preamp.
If I buy a Emotiva XPA-2 or XPA-3, Will I hear any hiss from the tweeters at:
a) My ear close to the tweeter.
b) My ear one foot away
c) My ear 3 feet away
At what level of S/N ratio does the hiss become audible.
Regards

Horace
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post #75 of 242 Old 03-03-2011, 09:02 AM
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good info, still confused
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post #76 of 242 Old 03-03-2011, 09:11 AM - Thread Starter
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What still confuses you?

"But this one goes up to 11"
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post #77 of 242 Old 03-05-2011, 05:35 AM
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I have lots of car amps for car audio systems - most are really low THD like 0.01 % up to 0.1%

I know they are 12 volt and requite lots of power but I already have them, will these work for home theater use - they are full range amps 10-20,000 hkz and I can get them powered no problem - but will these work properly

I want the retro skin back please
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post #78 of 242 Old 03-05-2011, 07:23 AM - Thread Starter
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Quote:
Originally Posted by leftkidney View Post

I have lots of car amps for car audio systems - most are really low THD like 0.01 % up to 0.1%

I know they are 12 volt and requite lots of power but I already have them, will these work for home theater use - they are full range amps 10-20,000 hkz and I can get them powered no problem - but will these work properly

You can use them. Whether they are the best option is another question. Due to the low power supply voltage, they likely have limited power into 8 ohm speakers.

I keep repeating this, but please post all amp questions in the receiver/amp thread, and only post to this thread if it's a comment or question, on the FAQ. Thanks!

"But this one goes up to 11"
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post #79 of 242 Old 03-10-2011, 04:14 PM
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I have a pair of axiom audio m80 tower speakers. Does anyone have a suggestion on what amp to use to drive these?
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post #80 of 242 Old 03-10-2011, 06:02 PM - Thread Starter
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I keep repeating this, but please post all amp questions in the receiver/amp thread, and only post to this thread if it's a comment or question, on the FAQ. Thanks!

This is 100% for your own good - you will get more responses!

"But this one goes up to 11"
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post #81 of 242 Old 03-13-2011, 06:15 PM
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just curious,, how long will a well built amp last?, I have a Adcom GFA-5800 that is around 15yrs old....
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post #82 of 242 Old 03-13-2011, 09:09 PM - Thread Starter
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Does no one read my posts saying to post questions unrelated to the FAQ outside this FAQ for the best responses?!

(Short answer, amps can last for a long time, an obvious point of failure is caps)

"But this one goes up to 11"
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post #83 of 242 Old 03-28-2011, 03:07 PM
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great thread!
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post #84 of 242 Old 03-29-2011, 10:52 AM
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Just stumbled on this thread. Michael, great read as others have stated and thanks for putting the time and thought into this (as you always do in your posts)!

Ray

 

"Listen with an open heart and mind."

 

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post #85 of 242 Old 04-06-2011, 08:45 AM
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That's a great post and should be required reading for serious audio students!
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post #86 of 242 Old 04-06-2011, 11:29 AM - Thread Starter
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Thanks. It needs some work, but I keep putting it off.

"But this one goes up to 11"
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post #87 of 242 Old 04-13-2011, 08:02 AM
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Hi MJH

Great first post! Thanks! I have bought a Anthem AVM 50v and am looking at getting the amp next... then interconnects...

I am trying to decide between the PVA7 and the MCA50! I would prefer 7 channels ideally but for now can settle on 5 channels until I have the physical room for 2 Amps.

I am using M&K LCR850 speakers with M&K S55 surrounds (rated at 25w - 200w) 4ohm.

Am I going to see a noticable difference with the MCA50 over the PVA7??

And should I use the balanced XLR outputs?? Again can there be a noticable difference (even if its small)??

Many thanks

LBH
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post #88 of 242 Old 04-13-2011, 08:16 AM - Thread Starter
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You will get better answers asking general amp questions outside the thread as not everyone reads this.

"But this one goes up to 11"
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post #89 of 242 Old 04-24-2011, 09:58 AM
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I would like to say that this is very informative thread.
I am in the market to buy a 3 or 5 Chanel amp. If I am getting this right, spending $5,000 on a amp w/20 year warranty (hint) VS a cheaper ($$$) amp with less warranty. what I am getting is a better warranty? being all other spec's are at least close to the same. as no one can tell the difference between sound quality. Am I paying to much for a name or are the BIG names worth the money? My dealer would say yes, but he is a salesman.
This high end amp does have 5 separate amps per Chanel, so all Chanel's driven power does not drop (5/150W=30W ch). at least that's what i was told.
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post #90 of 242 Old 04-24-2011, 11:02 AM - Thread Starter
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Amps can be divided into mono bloc type and shared power supply. If its a mono bloc design each amp has a dedicated power supply.

Neither is strictly better. For example, very good amps are made with a shared power supply which does have advantages. A shared power supply, when playing back movies, can be nice because not all channels need equal power. The shared power supply can be better because it can deliver extra power to needy channels. A monobloc amp is more limited in that way. But a mono bloc amp probably has less crosstalk between channels.

I assume that's what the dealer is saying when he's talking about some amp where each amp channel is separate, but I could be wrong.

I would post a message to the forum about your other question to get a better response.

"But this one goes up to 11"
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