[chashint]

Seeing that some ppl suggest that amps running within their specs will "color" the original source material, I wonder what manufacturer's would say if one was to ask them if they purposely designed their amps to alter the source material?

The specs on modern amps (and AVRs) for THD nominally being <.1% and frequency response often being +/-<1dB from 10HZ to >50kHZ suggests the answer to this is a resounding no.

 

[Wardsweb]

From my experience, amps can, but not always, have a signature sound. McIntosh comes to mind, it is different than a Pass Labs, in turn different from the SST Ampzilla 2000. That and I haven't even talked about tubes. SET amps being very different from Push-Pull. Throw in Pentode, Triode, and we still have to talk about topology. So, for me they can sound different.

This becomes very apparent when trying to get the synergy right in a system. An amp can compliment a speaker or it can make it unlistenable. Case in point, a speaker with a shrill high end can be tamed by a tube amp but the same amp can make a flat response speaker seem dull.

Now all of this has to be taken from your point of view and how you hear it and want to hear it. Some people like highs and some perfer more bass. Some will notice a substantial difference and others more of a nuance. There is no black or white but shades of grey.

 

[JerryLove]

The only spot I've noticed a difference between my McIntosh and Yammy Pro amps was on the B&W 801N, which spends a lot of time at 2ohms (where the Yammy doesn't really want to go).

I've noticed the difference between my Yammy and Marantz AVR's amp on more speakers than that; but again always on the hungry and/or low-resistance gear (hear it on the 801 MatrixII, but not on the PSB 400i).

Don't know if someone is still doing it: but there was a $10k challenge to anyone that could tell the difference between level-matched amps not driven into overload. Hundreds tried (at least one sponsor used to take the challenge to trade shows) but none won.

There are a lot of differences in amps; but a difference in sound between well constructed amps running (not overloaded) a speaker they are sufficient to run is not one of them.

 

[MagnusAtom]

Then here's how you can make an easy $10,000: http://tom-morrow-land.com/tests/ampchall/index.htm

Funny. Hundreds of people tried. No one managed to hear these differences in amps not over-driven.

Me, and a number of folks here might just be the outstanding ones with gifted ears then!

I don't mind having a look at the registration form. ")

 

[MagnusAtom]

From my experience, amps can, but not always, have a signature sound. McIntosh comes to mind, it is different than a Pass Labs, in turn different from the SST Ampzilla 2000. That and I haven't even talked about tubes. SET amps being very different from Push-Pull. Throw in Pentode, Triode, and we still have to talk about topology. So, for me they can sound different.

This becomes very apparent when trying to get the synergy right in a system. An amp can compliment a speaker or it can make it unlistenable. Case in point, a speaker with a shrill high end can be tamed by a tube amp but the same amp can make a flat response speaker seem dull.

Now all of this has to be taken from your point of view and how you hear it and want to hear it. Some people like highs and some perfer more bass. Some will notice a substantial difference and others more of a nuance. There is no black or white but shades of grey.

+1

 

[ericzim]

All properly built amps which are not being over driven will sound the same (the waveform out will look just like the waveform in only bigger). Since the amps we are discussing are intended for *reproduction* (as opposed to a guitar amp, which is intended for production); that is what it is supposed to be.

Some people like the effect of clipping on a tube amp; and so run tube amp or pre-amp stages above what the tube can flatly render. This does color the sound (as all overdriving does)

+1 Jerry hit the nail on the head.

 

[MagnusAtom]

I think in the real world, we have different habits of listening- I don't think anyone listens to music within a limited spl range.

 

[JerryLove]

I think in the real world, we have different habits of listening- I don't think anyone listens to music within a limited spl range.

I always listen to music in the range between 0db and 200db. In fact: I'd say I listen with an even more limited SPL than that, but I can say with surety between 0db and 200db.

 

[robbo266317]

I always listen to music in the range between 0db and 200db. In fact: I'd say I listen with an even more limited SPL than that, but I can say with surety between 0db and 200db.

:rofl::rofl::rofl:

I like your thinking :T

 

[MagnusAtom]

So when you reach 100db, do you still think all amplifiers sound the same?

 

[lcaillo]

100 dB would be very different under different conditions. Driving K-horns to that level and driving B&Ws to that level would likely have very different results, causing some amps to exceed their design limits and others not. We have to be careful about defining such conditions for the discussion to be meaningful.

 

[JerryLove]

So when you reach 100db, do you still think all amplifiers sound the same?

If the amplifier is not being over-driven then, "yes".

If the amplifier is clipping, or if the power-supply in the amp is underpowering it, or if the Ohm load-drop is too much for the ability to put out current, then "no".

I've been in both. I've had to buy amps to resolve sound problems. In all cases: I can reasonably point to the load being too much. (for example: In all cases, where the weaker amp was not having a problem, hooking up the more powerful amp made no difference at all in sound)

This is true regardless of SPL.

 

[MagnusAtom]

Pointing the mic from my listening position shows different curves with different amplifiers, in the same room setting-there was an obvious difference in frequencies of more than 10db, and in listening to different softwares, other amps were more exciting, another was more laid back, and then another, smoother. At the same gain, another brand had heavier bass, and then highs.

While hundreds may not have succeeded in the "all amplifiers sounding the same" challenge, hundreds of thousands can tell the difference.

Now, I have a 50 watt amplifier built to the design of a known amplifier brand, and while it is easy to be biased towards your own labour, I got to say, the known brand was better sounding, with and without a semi 'blind' test.

While I think some audiophile beliefs border on psychological, quite a number of amps I've tried are not, and probably not in your list of amps you've heard. Sorry, I just can't wrap my head around your approach, til I hear and know for a fact, like a measurement curve, or a well written white paper with reasonable and practical perimeters.

Well, I guess we'll have to agree to disagree.

 

[ericzim]

Pointing the mic from my listening position shows different curves with different amplifiers, in the same room setting-there was an obvious difference in frequencies of more than 10db, and in listening to different softwares, other amps were more exciting, another was more laid back, and then another, smoother. At the same gain, another brand had heavier bass, and then highs.

While hundreds may not have succeeded in the "all amplifiers sounding the same" challenge, hundreds of thousands can tell the difference.

Now, I have a 50 watt amplifier built to the design of a known amplifier brand, and while it is easy to be biased towards your own labour, I got to say, the known brand was better sounding, with and without a semi 'blind' test.

While I think some audiophile beliefs border on psychological, quite a number of amps I've tried are not, and probably not in your list of amps you've heard. Sorry, I just can't wrap my head around your approach, til I hear and know for a fact, like a measurement curve, or a well written white paper with reasonable and practical perimeters.

Well, I guess we'll have to agree to disagree.

Different amplifiers with different pre-amplifiers or are they seperates?

 

[AudiocRaver]

I'm going to add another voice of agreement with JerryLove on the topic, that different amplifiers operating within their linear ranges are going to sound the same. Then I'll disagree just a tiny bit, knowing that there are a lot of ways to design an amplifier, and that subtler types of distortion, like Intermodulation Distortion (IM) and Transient Intermodulation Distortion (TIM), when they exist (not so often these days), can be overlooked in specs and tend to only be heard with certain types of program material. One listener might hear it in the "tang" of a cymbal while another is paying attention to the vocalist. With a well-powered system, though, as already stated, it seems highly unlikely that such artifacts are measurable or audible.

The human ear is a very sensitive instrument. Unfortunately, it is also an instrument easily influenced, even easily fooled.

AudiocRaver

 

[JerryLove]

Pointing the mic from my listening position shows different curves with different amplifiers, in the same room setting-there was an obvious difference in frequencies of more than 10db

Can you please post your FR charts and describe the setup?

I could actually run a similar test (though if amp performance differences showed up on objective tests: this would have been settled *long* ago (note the lack of "do speakers color sound" discussions)).

Put up what you've got and I'll try the same with my mic, PSB 400i's and a trio of amps. See if I can replicate your results.

Human hearing is "below average" in the mammal world, and then brain processing kicks in to fool you further. There're upper-atmo balloons which listen for the tell-tale sounds of a nuclear explosion from the opposite side of the world; there is sonar and RF gear that can image spaces passively from background signal.

Let me know when you can walk into a room and, from ambient noise, describe the room to a resolution of a cm with even an active source (see bats), much less a passive one (see passive sonar array)

 

[yoda13]

The human ear is a very sensitive instrument. Unfortunately, it is also an instrument easily influenced, even easily fooled.

AudiocRaver

:T there you go!

 

[phreak]

AudiocRaver wrote:
The human ear is a very sensitive instrument. Unfortunately, it is also an instrument easily influenced, even easily fooled.


Best comment in the thread? Gets my vote.

 

[bluemax_1]

There seem to be two different sides of the discussion that aren't necessarily meeting in the middle.

1) Amps that are designed to replicate the input as accurately as possible (flat frequency response) AND working within their design limits sound the same with the same speakers

2( Different amps CAN sound different if:
a) one amp is working within its specs and the other is in distortion
b) one of the amps is (intentionally or otherwise) built with a 'house sound', i.e. a NON-FLAT frequency response. If you measure the input signal vs the output, these are easy to identify.

Personally, I prefer NOT to use amplifiers (or cables) as tone controls. I'd rather the amp not roll off the frequencies above 7-12kHz to make everything sound 'warm'. I'd prefer they not boost the 2kHz region slightly to make vocals sound more forward etc.

I would optimally prefer that the entire chain reproduce the recording as faithfully as possible, but as with any preferences, others may differ. Some prefer the types of distortions certain amps produce. IMO, a speaker that NEEDS a high frequency roll off to sound good is a flawed design. Likewise, a speaker that inherently and innately (due to its design and construction) rolls off the high end is also flawed. Both of those examples usually have some kind of odd behavior in the frequency response and/or off axis response.

If the amps play flat with minimal distortion and have enough power for what I'm using them for, that's good enough for me.


Max

 

[gsmollin]

There seem to be two different sides of the discussion that aren't necessarily meeting in the middle.

1) Amps that are designed to replicate the input as accurately as possible (flat frequency response) AND working within their design limits sound the same with the same speakers

2( Different amps CAN sound different if:
a) one amp is working within its specs and the other is in distortion
b) one of the amps is (intentionally or otherwise) built with a 'house sound', i.e. a NON-FLAT frequency response. If you measure the input signal vs the output, these are easy to identify.

Personally, I prefer NOT to use amplifiers (or cables) as tone controls. I'd rather the amp not roll off the frequencies above 7-12kHz to make everything sound 'warm'. I'd prefer they not boost the 2kHz region slightly to make vocals sound more forward etc.

I would optimally prefer that the entire chain reproduce the recording as faithfully as possible, but as with any preferences, others may differ. Some prefer the types of distortions certain amps produce. IMO, a speaker that NEEDS a high frequency roll off to sound good is a flawed design. Likewise, a speaker that inherently and innately (due to its design and construction) rolls off the high end is also flawed. Both of those examples usually have some kind of odd behavior in the frequency response and/or off axis response.

If the amps play flat with minimal distortion and have enough power for what I'm using them for, that's good enough for me.

Max

Well said, Max. It is worth noting that Mr Clark qualifies the amplifiers he uses in the amplifier challenge. So if he finds a prospective test amplifier with enough distortion to be audible in the test, he won't use it in the amplifier challenge, since that would cost him. So this "challenge" is pretty bogus. It is precisely those amplifiers with peculiar responses, and including clipping or power supply overload that makes amps sound different. Virtually identical amplifiers running under identical conditions sound the same. Ho hum.