If I don't need louder, does an external amp do anything for me? - Page 3

At any given point in time I believe a music waveform (as opposed to a single frequency test tone) contains multiple frequencies.

So, while I think that the amp probably does "feel" one combined impedance/load at any given point in time, I'd think the frequencies that make up the complex waveform would act according to the impedance at that frequency. Some amps can deal with that better than others when that complex interaction falls into the dip in impedance, such as my Studio 100s, that dip below 4 ohms from around 50Hz to about 200Hz, with min of something like 2.5 ohms around 90Hz.

Sure, power supply is a huge component that influences all of this. But the standard argument is "all amps", seemingly without the distinction that there can be a wide variation regarding design, etc.


This kind of stuff can get very technical, very fast. I don't claim to be the expert, either. But there is good reading here.

My point remains: the speaker is part of the circuit the amp makes when producing sound. Certain speakers (crossovers & drivers really) are going to influence how the amp behaves. Since amps are designed differently, two amps really can't behave the same with different sets of speakers.

If we are measuring 10 watts at 1kHz into a steady 8Ohms, then yes. I don't expect much variation in how any two decent amps will perform/measure, or "sound"

Yup. And some amps will be absolutely terrible at 2.5 ohms, which is why your bass could sound very weak/bad if you're using one amp vs. another. And the bass frequencies, i.e 90Hz, is where you need the most power.

^^^ This.

I spent a ton of money and feel good about being me, you should too! And obviously anyone who disagrees with me is trying to hurt me, so I have to fly off the handle at them!

Regarding everything else (and in response to the original question):

Most all of the minutia is already abstracted and handled by looking at power output values; you can thank Georg Ohm for that. And with that, we can ignore all manner of buzzword compliance and go back to the scheduled program.

I still think impedance dips represent the worse case scenario, and don't have to be viewed as something of much concern.

More of a concern, in my mind, if you send a signal which results in the speaker "unloading" and exceeding it's mechnical limits. I would be concerned about damage.

A brief overload, which results in a low impedance presented to the amp which results in a condition the power supply can't keep up with, seems like a minor issue. Unless the amp/receiver takes a long time to recover ( I have read that this is a possibility in some amps.)

I feel it's maybe best to avoid speakers known for totorting amps. Plenty of good speakers out there which behave pretty well, right?

AC2011 - confused yet?

I guess you've figured out by now what a hornet's nest you kicked over. While my initial recommendation to you stands - even more so now that I've read over these comments - you at least have several perspectives from which to draw a conclusion and potential path to follow.

Why I feel compelled to apologize for the childrens' antics I'll never know.

Whoa man! Now you're talking something that we should actually worry about, but [insert name of audio rag here] never told me about it, so now I'm going to re-regurgitate a ton of buzzwords in your face!

In all seriousness - I agree with your point about not picking nightmare load speakers, with some reservations (of course); seems common sensical to me!

Where I'd have reservations is roughly thus:

Going back to Ohm's Law - if the amplifier (any amplifier) can drive X W into XYZ R, it will work. So if you've got a speaker that drops down to 4 ohms at some point, and the amplifier has 4 ohm numbers (and I'm really okay with manufacturer's dynamic output values here) it shouldn't have a problem. Speakers that drop down to 1 ohm or less usually do it at one side of the FR spectrum and the advantage is: on the HF, there's usually not much content (and that that is, doesn't want a lot of power), and on the LF, it should be handled by an xover (*should*). And when all of that fails and you don't feel satisfied, the RMX5050 (or some other hilariously huge amplifier) is mere clicks away, and sure to destroy whatever hoity-toity speakers you're worried about with it's near bottomless amounts of output power.

As far as bass sounding "weak" or "bad" - I'm inclined to lean on room acoustics as the bigger deal here (or the speakers themselves, but that's it's own hornet's nest - plenty of people believe their speakers can never be the problem). If the amplifier can't "ring the bell" into whatever load, it'll either start clipping, it'll overheat, or it'll go into protection - sometimes all three. Sure, THD might rise with that dip, but even at 1%, why do we care? Not like the speaker is somehow bettering that...

Impedance changes are a fact of every speaker design.


The only time I've encounter damage to speakers or amp is in the "party" situation. For example, someone is using a $200 receiver to play through cheap loudspeakers at extraordinary loud volumes. Not a situation likely applicable to the average home theater.


Why limit your speaker choices?

Speaking of.

Why buy speakers if they require an expensive amp due to their exotic crossover design if there's equally good sounding speakers which don't?

Of course speakers are a personal choice, so maybe I can understand people falling in love with a speaker that has special needs.

Because some poet likes them!

Because you prefer the sound of one speaker vs. the other?

I never said expensive amp = good amp.

Its really simple if you have a good dealer try the external amp if you hear a difference you like keep it if not exchange it for a piece in your system that will make a difference.

I know this got way off topic from the OP and in his case, he should leave well enough alone.

So far the chat has been about amps and speakers leaving out the pre amp. The pre in most mass market AVRs are not great so they could be the reason why the amp portion sounds different.

I know in my systems I can swap my Hafler pre with my VAC pre and again get a different sound out of the SAME amp as well as change amps and keep the pre the same.

I have never added an external amp to an AVR but I do send the pre outs for the fronts thru my 2ch rig and just set the volume where it was matched with the AVR setup.

But then there is the camp that claims pre amps don't sound different either. So if all amps sound the same, and all pre amps sound the same and only speakers can sound different, there must be millions of wild imaginations running wild that think they can hear the differences between all these components when the same pc of music is used.

^^^

your last sentence pretty much covers the waterfront...

Stereophile does not appear to have reviewed and published measurements of your particular VAC tube preamp (or, at least, that review and those measurements are not yet in the online archive). But if the measurements of this $17,000 VAC tube preamp are at all representative, your front end likely does not "resolve" as much as it obscures.

http://www.stereophile.com/content/v...r-measurements

AJ

^^^

there you go, interjecting fact into the discussion aj...

wow, what a piece of junk...

the most damning assessment is ja's last paragraph on page 2... you can tell how much it physically pained him to write that...

If receiver preamps have audible distortion, I would be curious as to why.

In schematics I have looked at, the pre amp in a receiver is a volume chip, discounting the DAC.

And a volume chip, based on what I have seen, is just an op amp.

Admittedly, there was a designer of high end (expensive) audio gear who posted that op amps are a bad choice for volume control. I didn't understand this arguments against.

Hm, your point seems to be that because there are some badly designed speakers out there (just like there are some badly designed amps, see below), we should all buy 700wpc amps, just in case.

But even so, there shouldn't be audible differences among defect-free modern amps.


Sure, because your VAC most likely colors the sound. It's totally fine if you like it, but it doesn't make it accurate.

No, that is not my point. Just because a speaker is harder to drive by a cheaply-made/designed amp, doesn't mean that it is badly designed. There are many types of speakers: horn, electrostatic, cone-based, hybrids, etc. Why should they all be designed to maximize the performance of the amp section of a $100 receiver?


My point is that you don't listen to just an amp. You listen to the way speakers (including their crossover design, driver choice, etc) interact with an amp. Some interact better (electrically and audibly) with certain amps, than others. That is all I'd like to say.

Why isn't the cheapest possible receiver with enough inputs the #1 choice for everyone on this forum? All the people that went from weak receivers to more powerful separates are just imagining things? That's a lot of people. If I wanted to get rich quick, I'd target these folks and slap a $10,000 price tag on a cheap pro-amp and watch the millions come in.

And if there isn't a dealer willing to do that one can usually rent a pro amp for short money. Maybe $20-$25 for a weekend or something like that.

For the same reason Zeus is not the choice for everyone on Gaia....

Sort of like Lexicon did with their rebadged Oppo player that they marked up 1500%?

Or what TUC does with their amp/avr "upgrades"?

No evidence that either of those work better than the base electronics (other than manufacturers claims and user testimonials), yet they still moved product.

The reason most don't pick an inexpensive receiver is the advanced DSP options and other features, not the additional power. As to whether people are imagining things, that does appear to be the consensus result of DBT's.

Do these topics ever end well???

No. Not as long as people keep asking them

I've yet to read of anyone changing their minds based on discussion here. I'll try my hardest to avoid being drawn into additional conversation. At best, I think it's a waste of my keyboard time

And as long as some continue to provide misleading information, however deep their belief system may be.

Hey, when over half of the population believes in ghosts, why should we be surprised when some claim to hear differences between cheap and pricey amps?

Maybe you could highlight/repost so of the misleading information. Just for laughs, of course.

I did. I got in an argument about receivers sounding different in stereo mode. I had always heard Yamaha is bright and Denon is neutral and Onkyo is bright and Marantz is warm and so I always thought that was the way it was. I ended up going to a store where I could setup a blind A/B test and found out that I was wrong. I picked the one that sounded best and pretty much every time I had picked a different one. So I was appreciative of the education I got here, although I did have to go out and prove it for myself. At least I don't still believe that garbage like you should never buy a Yamaha/Onkyo with Klipsch speakers because the combination is too bright. I can’t even believe I actually fell for it to begin with. I also bought a Rotel amp to see if it would sound better than my Denon receiver and it didn’t. So see, some people actually do go out and try this stuff after seeing threads like this and find out the truth for themselves.

That is encouraging. Listening is always the best way to drawn conclusions appropriate for your situation. Regardless if the outcome supports online dogmas!

I can't hear measurements.

He also said this

""Listening: Do you believe in magic?

I've already tipped my hand that, when everything clicks, the VAC Renaissance Signature was capable of truly magical performance. But what exactly was it about this preamp that made it so captivating, and how did it measure up in all of the areas we audiophiles hold dear?

The single most impressive thing about the VAC, and the area where it stood head and shoulders above any other preamp I'd heard, was its resolution. At low levels, whether a single plaintive note fading ephemerally into the surrounding ambience or a subtle countermelody buried deep in the orchestration, the Signature retrieved more tonal, spatial, and temporal information than any other unit I've heard. With the VAC, there was never any question that an orchestral section was composed of multiple instruments, each in a distinct position and each with a characteristic tone, texture, and presence. A lot of top-quality gear reveals this level of detail in the major components of the orchestration, or in the front half of the stage, but where the VAC really stood out was in how well, at lower levels, it reproduced details of instruments buried way down in the mix or at the rear of the stage. ""