I suppose that into an 8 ohm resistive load two identically measuring amplifiers could sound the same . . .
However, put them in the real world and they may sound different.
Now, before I get accused of going over to the dark side, let me stress most of what I read as the cause of amplifiers sounding different, I have to dismiss knowing what I know about electronics.
Voicing an amplifier for a specific sound is a perfectly legitimate activity if that is what floats your boat. Just don't claim your amp sounds the way it does based on nonsense engineering.
And, Like RF (bless that man) says in the piece above, be honest - don't fool yourself or others.
However, put them in the real world and they may sound different.
Now, before I get accused of going over to the dark side, let me stress most of what I read as the cause of amplifiers sounding different, I have to dismiss knowing what I know about electronics.
Voicing an amplifier for a specific sound is a perfectly legitimate activity if that is what floats your boat. Just don't claim your amp sounds the way it does based on nonsense engineering.
And, Like RF (bless that man) says in the piece above, be honest - don't fool yourself or others.
Also true for the vast majority of loudspeakers that exist.
True if your reference standard is sighted evalutions, but that is about the problems with the test. not any general technical reality.
In fact a lot of amplifiers for which that claim has been made, they sound like any other good amp as well.
Which is true due the poorly conditioned hypergenerality of the statement...
The word "perhaps" is such a weasel word that any statement containing it contains very little useful knowledge.
Or not, because just 'cause an amp is voiced by some eggspurt, doesn't mean that it actually sounds good.
They have converged on flat frequency response and low distotion. Let's not belabor widely accepted practice.
False. Some pretty crazy junk you'd never want to own can still sound good.
I don't know that that means,but high aural acceptability can and is often cookbooked.
Thanks Jay. Nice to read a bit on Thiel spealers. In video the two speakers looked like they have comparatively big tweeters; so I tried to relate it with F.A.S.T. type of two way speakers. So was curious to learn. Any idea which is the other one is ?Thiel model 01. What else do you expect
Regards.
Problems begin when we don't use PURELY RESISTIVE loads, which are really labratoray standards which do not exist in real life and operation. It is incredible what some speakers present as a load to the amp attached to them, let me just mention the Apogees. They have a great sound provided your amp has real life muscle and can deal with very complex loads.
By "real life muscle" I refer to their ability to deal with loads which twist and turn fromnoinal 8 ohms down to say 3 Ohms and up to say 16 Ohms, in comibnation with rather nasty phase shfts of +/- 70 degrees. That's DOUBLE the nominal power output, with -70 degrees, that soon becomes a whole lot of amps not many can actually produce. So either you give up some power output or you beef it up if you want them to sound about the same at 1W output and say 100W peaks.
About what Andrew catered for in his power amp specifications when he mentioned its performance at 3 Ohms in parallel with 1uF or thereabouts. What we saw was a rise in THD as the amp started to struggle with extraordinary power demands. The real question is how far are you willing to go with power demands into real life speakers rather than lab resistors. Ask a plain vanilla power amp to drive the said Apogees to say its nominal power level -1 dB and you soon understand why those speakers were called "The Amp Killers". Most amps will TRY to work, but they will very appreciately change their transient tonality as their protection circuits kick in and start limiting the output stage. Sound loses its definition, resolution and kick and begins to sound shallow and insubstantial. Some may even start deliverng bluish smoke.
And the Apogees are by no means alone - consider the old and in their time revered AR3a Improved and Yamaha NS-1000 speakers. This logic applies to sighted or unsighted tests as well - the end result will in inay case be influenced by load quality. Use a nice and clean speaker and then retry with a notoriously difficult speaker and you will get two very different test results. So, which one is representative of the amp?
By "real life muscle" I refer to their ability to deal with loads which twist and turn fromnoinal 8 ohms down to say 3 Ohms and up to say 16 Ohms, in comibnation with rather nasty phase shfts of +/- 70 degrees. That's DOUBLE the nominal power output, with -70 degrees, that soon becomes a whole lot of amps not many can actually produce. So either you give up some power output or you beef it up if you want them to sound about the same at 1W output and say 100W peaks.
About what Andrew catered for in his power amp specifications when he mentioned its performance at 3 Ohms in parallel with 1uF or thereabouts. What we saw was a rise in THD as the amp started to struggle with extraordinary power demands. The real question is how far are you willing to go with power demands into real life speakers rather than lab resistors. Ask a plain vanilla power amp to drive the said Apogees to say its nominal power level -1 dB and you soon understand why those speakers were called "The Amp Killers". Most amps will TRY to work, but they will very appreciately change their transient tonality as their protection circuits kick in and start limiting the output stage. Sound loses its definition, resolution and kick and begins to sound shallow and insubstantial. Some may even start deliverng bluish smoke.
And the Apogees are by no means alone - consider the old and in their time revered AR3a Improved and Yamaha NS-1000 speakers. This logic applies to sighted or unsighted tests as well - the end result will in inay case be influenced by load quality. Use a nice and clean speaker and then retry with a notoriously difficult speaker and you will get two very different test results. So, which one is representative of the amp?
Bar the full range and scintilla Apogees are generally fairly resistive in their load. As Nelson said (paraphrase) it's not hard to make an amplifier to drive apogees, you just have to get a bit medieval.
And a well designed amplifier, operated within its power rating should have no problems with this. If they measure differently into reactive loads then you have a mechanism for a sound difference. If they measure the same then they should still sound the same.
Given that most of the designs people do here in solid state are in the 100-200W range with considerable current drive capability I don't see this as a problem. But happy to be proved wrong. Of course plenty of boutique audio that gets great reviews and cannot do flat FR 20-20kHz!
To misquote the late great Terry Pratchett, there is a lot of headology going on.
Have posted this link before but look at the measurements of the JC-1 power amp Parasound Halo JC 1 monoblock power amplifier Measurements | Stereophile.com
That should drive anything and be excessive for most use cases. I'd go as far as to say that, for a production unit it's pretty good value. Certainly if I owned one I'd be in absolutely no rush to try and supplant it, other than for something smaller/more efficient. You will notice that the simulated speaker load causes no problems other than a teensy rise in distortion above 20KHz. Bonsai will fret about 0.06% at 35KHz, but I'm pretty sure I wouldn't be able to here that.
I will also note I don't spent $5k on my cars let alone my amplifiers...
Old Apogees are not so hard to drive, my Duettas are at least 3Ohms and run easy with a Vincent 236 giving 150 W into 8 ohms or with TacT 2150 Digital amp, giving the same power but different sound.
Its only the Scintilla with 1 ohm which is really a power sucker ( i have one here actually), but many modern amps can handle them, but i hear they do not sound all the same.
The FR had 4 Ohm transformers, thus not very efficient, direct drive is another thing.
I have them also here. With new custom made transformers for MT and TW, 3 Ohms and low loss, ready for 250 W. The old ones for the MT were really crappy, saturation at maybe 80 Watt, giving strange sonic results with several amps.
There are many other speakers on the market today, which are power demanding due the complex passive x-overs and equalizers.
This problem can be handled with Neodymium magnets raising the efficiency .
Its only the Scintilla with 1 ohm which is really a power sucker ( i have one here actually), but many modern amps can handle them, but i hear they do not sound all the same.
The FR had 4 Ohm transformers, thus not very efficient, direct drive is another thing.
I have them also here. With new custom made transformers for MT and TW, 3 Ohms and low loss, ready for 250 W. The old ones for the MT were really crappy, saturation at maybe 80 Watt, giving strange sonic results with several amps.
There are many other speakers on the market today, which are power demanding due the complex passive x-overs and equalizers.
This problem can be handled with Neodymium magnets raising the efficiency .
@SY
What is a power cube? I am not familiar with the term and(or the device. Please explain.
@billshureV
"Should" is right because it is a conditional. People here yes, I know for a fact (albeit with limited number of test items) that John and Nelson do pay particular attention to the current factor, and for that I for one cheer them on. For the others, do be careful. I have seen some very expensive amps boast of some incredible current surges they are capapble of, but reading on, I noticed that was good for 1 mS only. In my view, that is not a useful time interval, IEC takes 20 mS for a standard, and even that I feel is too short, but that is debatable. Particularly useless are Harman's specs, which quote numbers like more than 100 Amps, but with no elaboration, into which load, for how long, etc. To me, as such, these specs are meaningless. Goes for a number of similar specs with no clarifying data.
I did not refer to outlandish power outputs, I was quite specfic, up to nominal power ratings at -1 dB. Eg, for a 100WPC amp, that's about 80WPC or so, actually LESS than even full nominal power.
Re: Andrew's understsnding of ratings. Personally, I completely agree with them and consider them infinitely more truly informative than the vast majority. More than usual can't hurt anybody, all he's really telling you is that it's very unlikely that anything happining in real life will phase that amp. Supremely clean and most load tolerant, if you like, and in no uncertain terms. I prefer my meat a bit overcooked rather than a bit undercooked.
This is not a therotecal discussion. When I was refreshing my old Marantz 170DC power amp, what bothered me was a slight but perceptible change of tonality when pushed relatively har. It's rated at 85WPC, but showed this change when PEAKS started hitting the 60 WPC mark. The power transformer sure is hefty enough, fuse protected at just over 600 VA. The sigle supply caps were rated at 12,000 uF and were, at the time, about 35 years old. I swapped that for two 22,000uF caps from BC and, sure enough, the effect was gone without trace. The caps were brand new, already and effect in itself, and were almost double the original value (+83.3%), finishing it all off. That amp really came on song.
The only perplexing thing about it was that in their upmarket separates component Marantz chose to use 1 dual concentric 2x12,000uF cap, wheras in their meinstream model using exactly the same electronics and with exactly the same nominal power rating, model 1182DC integrated amp, uses two discrete Elna caps each rated at 15,000 uF. Strange are the ways of cost cutting.
What is a power cube? I am not familiar with the term and(or the device. Please explain.
@billshureV
"Should" is right because it is a conditional. People here yes, I know for a fact (albeit with limited number of test items) that John and Nelson do pay particular attention to the current factor, and for that I for one cheer them on. For the others, do be careful. I have seen some very expensive amps boast of some incredible current surges they are capapble of, but reading on, I noticed that was good for 1 mS only. In my view, that is not a useful time interval, IEC takes 20 mS for a standard, and even that I feel is too short, but that is debatable. Particularly useless are Harman's specs, which quote numbers like more than 100 Amps, but with no elaboration, into which load, for how long, etc. To me, as such, these specs are meaningless. Goes for a number of similar specs with no clarifying data.
I did not refer to outlandish power outputs, I was quite specfic, up to nominal power ratings at -1 dB. Eg, for a 100WPC amp, that's about 80WPC or so, actually LESS than even full nominal power.
Re: Andrew's understsnding of ratings. Personally, I completely agree with them and consider them infinitely more truly informative than the vast majority. More than usual can't hurt anybody, all he's really telling you is that it's very unlikely that anything happining in real life will phase that amp. Supremely clean and most load tolerant, if you like, and in no uncertain terms. I prefer my meat a bit overcooked rather than a bit undercooked.
This is not a therotecal discussion. When I was refreshing my old Marantz 170DC power amp, what bothered me was a slight but perceptible change of tonality when pushed relatively har. It's rated at 85WPC, but showed this change when PEAKS started hitting the 60 WPC mark. The power transformer sure is hefty enough, fuse protected at just over 600 VA. The sigle supply caps were rated at 12,000 uF and were, at the time, about 35 years old. I swapped that for two 22,000uF caps from BC and, sure enough, the effect was gone without trace. The caps were brand new, already and effect in itself, and were almost double the original value (+83.3%), finishing it all off. That amp really came on song.
The only perplexing thing about it was that in their upmarket separates component Marantz chose to use 1 dual concentric 2x12,000uF cap, wheras in their meinstream model using exactly the same electronics and with exactly the same nominal power rating, model 1182DC integrated amp, uses two discrete Elna caps each rated at 15,000 uF. Strange are the ways of cost cutting.
Last edited:
I don't know Apogees' nodels at all. The one I refer to is a big floorstander, owned by a good friend, who ended up by ordering a hand made power amp endowed with at least four pairs of hand selected Motorola TO-3 power devices per channel, mounted on unusually large chimeny type external heat sinks, and a 1000 VA power transformer followed by 2*33,000uF caps per channel.
After an hour of operation, those heatsinks will become pretty hot if music is played loudly (but not too loudly, i.e. still in the comfortable listening range).
I thought Andrew just used a combination of Self and Cordell for his ratings advice, backed up with a bit of practical experience?
We need to divide between commercial amps build to a cost and with marketing involved and things people here build for their own use. The average DIY build is generally well overspecified (with notable exceptions) but also the average DIY build often has a system in mind.
Of course there is also an argument that having an amp that runs out of steam at 80% of 'rated' power is a good thing as you know to turn it down a bit before you kill something (like your ears).
We need to divide between commercial amps build to a cost and with marketing involved and things people here build for their own use. The average DIY build is generally well overspecified (with notable exceptions) but also the average DIY build often has a system in mind.
Of course there is also an argument that having an amp that runs out of steam at 80% of 'rated' power is a good thing as you know to turn it down a bit before you kill something (like your ears).
@dvv
I suspect those were the Full Range, 3 Way, 202 cm high, not very effcient truly, and the original transformers were crap. The woofer is 1.8 ohm DC Resistance and impedance is pretty much resistive. Actual Digital amps drive this easy and cost no fortune.
The MT is now 3 ohms with mynew transformers and veeeeeeeeeeeeeery sensitive, 50 Watt do the job, TW nearby as sensitive and with 100 Watt ok if active x-over is at 5Khz or higher.
With the old trafos you need at least 5 times more power and 3-way active means 6 monos or similar
@billshurv
the Scintilla is no more mine, im actually refurbishing them complete for a new owner.
Duetta is at home, FR wait for new ribs which are here sitting on a pile of other stuff waiting to be done, later they should replace the duettas which i will keep in my cellar.
The Goldmund is also here in store, at home is an original and refurbished EMT 930.
So now you know my kids
I suspect those were the Full Range, 3 Way, 202 cm high, not very effcient truly, and the original transformers were crap. The woofer is 1.8 ohm DC Resistance and impedance is pretty much resistive. Actual Digital amps drive this easy and cost no fortune.
The MT is now 3 ohms with mynew transformers and veeeeeeeeeeeeeery sensitive, 50 Watt do the job, TW nearby as sensitive and with 100 Watt ok if active x-over is at 5Khz or higher.
With the old trafos you need at least 5 times more power and 3-way active means 6 monos or similar
@billshurv
the Scintilla is no more mine, im actually refurbishing them complete for a new owner.
Duetta is at home, FR wait for new ribs which are here sitting on a pile of other stuff waiting to be done, later they should replace the duettas which i will keep in my cellar.
The Goldmund is also here in store, at home is an original and refurbished EMT 930.
So now you know my kids
@dvv
I suspect those were the Full Range, 3 Way, 202 cm high, not very effcient truly, and the original transformers were crap. The woofer is 1.8 ohm DC Resistance and impedance is pretty much resistive. Actual Digital amps drive this easy and cost no fortune.
The MT is now 3 ohms with mynew transformers and veeeeeeeeeeeeeery sensitive, 50 Watt do the job, TW nearby as sensitive and with 100 Watt ok if active x-over is at 5Khz or higher.
With the old trafos you need at least 5 times more power and 3-way active means 6 monos or similar
...
That'd the one, Groove T. It's an older version, if memory serves it was purchased in 1990, and to be sure, it still sounds great-
- Status
- Not open for further replies.