If all well designed amplifiers are difficult to distinguish

[davedotco]

I would disagree, it would be fine. Music only requires intermittent high power, not continuous.

Then why, if that power is sufficient, do not mainstream amplifiers, that typically have power supplies in the range I mention, fail to double their power into lower impedance loads? Or does that not matter on "music".

I am left wondering why Roksan would bother to fit a 700va supply into Vlad's K2 amplifier or why Per Abrahamsen would fit an expensive 1000va Noratel transformer into iO's new V20 amplifier.

 

[SteveR750]

I would disagree, it would be fine. Music only requires intermittent high power, not continuous.

Then why, if that power is sufficient, do not mainstream amplifiers, that typically have power supplies in the range I mention, fail to double their power into lower impedance loads? Or does that not matter on "music".

I am left wondering why Roksan would bother to fit a 700va supply into Vlad's K2 amplifier or why Per Abrahamsen would fit an expensive 1000va Noratel transformer into iO's new V20 amplifier.

Dave, good post, I was thinking exacty the same.

Trev, it's lot more quantitative than simply doubling the power. Most cheap amps cannot do that by the way, and very few at any price actually double, good ones come close. What about rise time? Slew rate? You've positioned yourself as the black and white engineer, so you need to describe "good" with numbers.

 

[TrevC]

I would disagree, it would be fine. Music only requires intermittent high power, not continuous.

Then why, if that power is sufficient, do not mainstream amplifiers, that typically have power supplies in the range I mention, fail to double their power into lower impedance loads? Or does that not matter on "music".

I am left wondering why Roksan would bother to fit a 700va supply into Vlad's K2 amplifier or why Per Abrahamsen would fit an expensive 1000va Noratel transformer into iO's new V20 amplifier.

Perhaps you should ask them. The Roksan transformer doesn't look that big.

 

[pauln]

There's a nice article here that explains reasonably simply why this power doubling as impedance halves is really a theoretical ideal rather than something that can be achieved in the real world. Manufacturers who claim that their equipment can achieve this feat 'may' be understating the 8 ohm power output for marketing reasons.

For those that aren't sure, audiophile amps operate under the same laws of physics as pro amps...

http://www.prosoundweb.com/article/print/amplifier_power_master_class_not_all_ratings_are_similar

 

[steve_1979]

Max Flinn, please come back, we miss you.....

Max and Thompson posting on the same forum. Now that would be a joy to read.

 

[davedotco]

I would disagree, it would be fine. Music only requires intermittent high power, not continuous.

Then why, if that power is sufficient, do not mainstream amplifiers, that typically have power supplies in the range I mention, fail to double their power into lower impedance loads? Or does that not matter on "music".

I am left wondering why Roksan would bother to fit a 700va supply into Vlad's K2 amplifier or why Per Abrahamsen would fit an expensive 1000va Noratel transformer into iO's new V20 amplifier.

Perhaps you should ask them. The Roksan transformer doesn't look that big.

Roksan claim 700va, though I agree, it does not look that big, but then I am not an expert on transformers.

As for asking the manufacturers, I have done so many times in my 40 years in and around the hi-fi industry. One or two manufacturers have attempted to explain this in a sensible manner, including Touraj Moghaddam, designer of the original Roksan amplifiers, but most resort to the cop out, "because it sounds better".

I am trying to reconcile my own experience over these years that tells me that, in general, all the best sounding amplifiers have big power supplies and that this is apparent even at quite modest volume levels. This is personal experience of course, anecdotal evidence if you prefer, not scientific proof.

I entirely understand that music reproduction in the home rarely requires substantial continuous output, but ever since I became the owner of my first 'heavyweight' amplifier (a Phase Linear 400 in 1975), I have always prefered more powerful amplifiers with big power supplies. (Not always quite the same thing).

On the other hand I constantly hear more modest powered amplifiers running out of power, most recently a Pavarotti aria (Decca's 1978 recording of Tosca) that virtually distroyed (sonically, not physically) a Rotel RA12/B&WCM1 setup at even fairly modest average levels and on another recent occasion, some modern r&b, (Robin Thicke) that caused an Arcam A19 to lose complete control at the modestly loud levels I was playing at, even with 'sensible' speakers, the Zensor 5.

 

[lindsayt]

Dave, good post, I was thinking exacty the same.

Trev, it's lot more quantitative than simply doubling the power. Most cheap amps cannot do that by the way, and very few at any price actually double, good ones come close. What about rise time? Slew rate? You've positioned yourself as the black and white engineer, so you need to describe "good" with numbers.

I have 2 amplifiers:

Amplifier A delivers 300 watts stereo into 8 ohms (Total harmonic and intermodulation distortion less than 0.1% for continuous sine waves at all frequencies from 20hz to 20khz). It delivers 600 stereo watts into 4 ohms (Total harmonic and intermodulation distortion less than 0.2% for continuous sine waves at all frequencies from 20hz to 20khz). It has a rise time of 7 microseconds. A slew rate of 50 volts per microsecond into an 8 ohm load. Damping factor is greater than 200 at any frequency from 20 hz to 1 khz into an 8 ohm load.

Amplifier B delivers 2 watts into 8 ohms. It doesn't get close to doubling its power into 4 ohms. It's damping factor is way less than 200 into an 8 ohm load. I've no idea what the rise time and slew rate is for this amp.

For the type of speakers owned by most people reading this, I'd take Amplifier A, any day of the week.

For my speakers I prefer Amplifier B.

 

[matt49]

For my speakers I prefer Amplifier B.

Euphonic distortion?

I'm not trying to be controversial: it's just that this evening I heard a pretty expensive valve DAC/preamp (Lampizator 7) in my system at home (Sanders Magtech power amp, Martin Logan Montis). There was something about the Lampizator that sounded wonderful: maybe that "holographic" thing people talk about. But there was also something that sounded downright annoying. It was a bit like wacking loads of vibrato on the mid-range. Voices warbling and trilling all over the place. I can imagine really liking it and really disliking it at the same time.

 

[davedotco]

Dave, good post, I was thinking exacty the same.

Trev, it's lot more quantitative than simply doubling the power. Most cheap amps cannot do that by the way, and very few at any price actually double, good ones come close. What about rise time? Slew rate? You've positioned yourself as the black and white engineer, so you need to describe "good" with numbers.

I have 2 amplifiers:

Amplifier A delivers 300 watts stereo into 8 ohms (Total harmonic and intermodulation distortion less than 0.1% for continuous sine waves at all frequencies from 20hz to 20khz). It delivers 600 stereo watts into 4 ohms (Total harmonic and intermodulation distortion less than 0.2% for continuous sine waves at all frequencies from 20hz to 20khz). It has a rise time of 7 microseconds. A slew rate of 50 volts per microsecond into an 8 ohm load. Damping factor is greater than 200 at any frequency from 20 hz to 1 khz into an 8 ohm load.

Amplifier B delivers 2 watts into 8 ohms. It doesn't get close to doubling its power into 4 ohms. It's damping factor is way less than 200 into an 8 ohm load. I've no idea what the rise time and slew rate is for this amp.

For the type of speakers owned by most people reading this, I'd take Amplifier A, any day of the week.

For my speakers I prefer Amplifier B.

Well, don't leave us hanging.......

What speakers are you currently using?

 

[davedotco]

Don't worry matt.......

It's just revealing the 'emotion' in the misic........*ROFL*

 

[lindsayt]

No, it doesn't sound like euphonic distortion to me. Sounds like a more realistic, less synthetic, midrange with better low level detail. Although there's not a big difference between my amps with my speakers.

My speakers are EV Patrician 800's.

 

[MeanandGreen]

Sugden A21SE vs. NAD C 356BEE.

Which one is a better amplifier and why?

Out of the two I'd choose the NAD. I've no experience with Sugden, but the quoted specs for it are a bit vague and very poor for the price IMO.

I do admit I'm biased towards NAD amps.

High power & low distortion at 20hz-20Khz both channels driven, good S/N, much more flexable conectivity with more inputs, plus a digital input (with the optional DAC module), headphone jack, bypassable tone controls, the usual pre/power conectivity (I know the Sugden has that too), but the NAD gives pretty much everything you could ask for in an amplifer. All it lacks is a phono stage, but NAD make separate ones anyway.

NAD tells you what the power consumption is, Sugden don't as far as I can see.

Sugden also don't quote the THD and they don't tell you how they measured the 30W output. Yes at 8 ohms with both channels, but at what frequency range and with how much distortion?

Personally I wouldn't even consider the Sugden. £2400 for the on paper specs I've just read, no thanks!

Wouldn't you at least want to hear it for yourself first?

NAD make good kit, but c'mon

From what I read about it's specs no I wouldn't want to hear it. I have no desire to spend that sort of money on an integrated amp. I really do not think it's necessary, electronic components are cheap. There is no justification for the price tag and the specs are vague to say the least.

When I listen to music using my C326 BEE or C350 either with speakers or headphones I feel like I'm hearing an accurate recreation of the recording. I can clearly tell the difference between sound quality on recordings, the overall presentation sounds 3D and detailed. At high volume levels the sound can be felt and I've never ran into clipping with either amp.

Basically what I'm saying is with my £300 - £350 amps I don't notice anything being added or taken away from the music. Great recordings sound great, poor ones sound poor. All the features and conectivity I need is catered for too, so for me I don't feel the need to go any further up the price ladder.

 

[davedotco]

No, it doesn't sound like euphonic distortion to me. Sounds like a more realistic, less synthetic, midrange with better low level detail. Although there's not a big difference between my amps with my speakers.

My speakers are EV Patrician 800's.

With your speakers having a sensitivity in excess of 100dB/watt, your 2watt amplifier would have almost exactly the same headroom as Vlads 170watt Roksan K2 into a pair of CM1s.

Interesting......

 

[FennerMachine]

No, it doesn't sound like euphonic distortion to me. Sounds like a more realistic, less synthetic, midrange with better low level detail. Although there's not a big difference between my amps with my speakers.

My speakers are EV Patrician 800's.

Nice!

 

[lindsayt]

Matt, I don't have accurate measurements of any of my amps. Not at all the power levels I use them with my speakers. Do you have accurate measurements of your amplification at all power levels that would be used with my speakers?

I suppose we could take a wild guess and extrapolate the THD+N graphs for a selection of amps. On the whole, the outlook for solid state amps does not look good when we extrapolate down to microwatt power levels.

How do I know if I have euphonic distortion? By listening, is the best way that I've come up with so far.

How do you know whether I have or I haven't got any detectable euphonic distortion from my 2 watt amp with my speakers at my usual listening levels (40 dbs to 90 dbs)?

 

[Vladimir]

Preamps and rubbish volume pots aside, two things may affect FR in aplifiers, their power envelope and the output impedance. Considering most amps have DF of 40 and above, that is rarely an issue. What we are left with is how ignorant an amplifier can be towards speaker impedances.

 

[Vladimir]

Oi! 5am already?

 

[matt49]

No, it doesn't sound like euphonic distortion to me. Sounds like a more realistic, less synthetic, midrange with better low level detail. Although there's not a big difference between my amps with my speakers.

It may or may not be euphonic distortion. How would we know? Do you have accurate measurements of the amp?

 

[lindsayt]

...Yeah, and I bet their owners have no sense of humour.

What's with the hugely insulting and totally wide of the mark ad hominem?

And the completely off-topic rant about Patricians? There's nothing to stop you starting a new thread where you can talk about speaker styling and model names as much as you want.

 

[davedotco]

How do you know whether I have or I haven't got any detectable euphonic distortion from my 2 watt amp with my speakers at my usual listening levels (40 dbs to 90 dbs)?

Er, by design.

Valves and horns are essentially non linear devices, irrespective of the power levels. This type of distortion is simple harmonic and very similar to that produced by the ear itself. Air does not compress in a linear fashion, either in the ear or in the horn speaker so it is extremely difficult to distinquish one from the other.

Horn distortion is measurable but masked (as distortion) by similar effects in the ear itself. Quite high levels of distortion may be detected by the ear but interpreted as something else, something that will not happen with the many conventional speakers where the distortion (cone breakup for example) is more objectional.

There is a subjective 'liveness' about the valve/horn combination that is enticing and great fun, I have never experienced the Patricians but I am familier with big, single and dual 15 inch and horn systems (Hartsfields, Soveriegns, La Scala etc) so I understand the appeal.

I have often spoken fondly of my JBL 4332 system, slightly more space friendly than some of the other models mentioned, but still far to large for most homes. These were one of the most enjoyable speakers I ever owned, but like the Patricians, virtually unobtainable in these times.

 

[TrevC]

I would disagree, it would be fine. Music only requires intermittent high power, not continuous.

Then why, if that power is sufficient, do not mainstream amplifiers, that typically have power supplies in the range I mention, fail to double their power into lower impedance loads? Or does that not matter on "music".

I am left wondering why Roksan would bother to fit a 700va supply into Vlad's K2 amplifier or why Per Abrahamsen would fit an expensive 1000va Noratel transformer into iO's new V20 amplifier.

Dave, good post, I was thinking exacty the same.

Trev, it's lot more quantitative than simply doubling the power. Most cheap amps cannot do that by the way, and very few at any price actually double, good ones come close. What about rise time? Slew rate? You've positioned yourself as the black and white engineer, so you need to describe "good" with numbers.

I already told you, electronics is cheap. There's no reason to think that an expensive amplifier will be better than an inexpensive one at reproducing a square wave if everything else is as good. I think it's you that thinks in black and white.

 

[TrevC]

No, it doesn't sound like euphonic distortion to me. Sounds like a more realistic, less synthetic, midrange with better low level detail. Although there's not a big difference between my amps with my speakers.

My speakers are EV Patrician 800's.

With your speakers having a sensitivity in excess of 100dB/watt, your 2watt amplifier would have almost exactly the same headroom as Vlads 170watt Roksan K2 into a pair of CM1s.

Interesting......

So you can use a really cheap amp with very expensive speakers and it will work well.

 

[TrevC]

Quick question off topic.

So non of you guys believe in a God or something greater than yourself?

Do you all believe only in the science of men?

Firmly believe in God and love science

Evolution?

 

[cheeseboy]

So you can use a really cheap amp with very expensive speakers and it will work well.

for example...

http://www.youtube.com/watch?v=WsPjsA6Cln8

 

[matt49]

...Yeah, and I bet their owners have no sense of humour.

What's with the hugely insulting and totally wide of the mark ad hominem?

And the completely off-topic rant about Patricians? There's nothing to stop you starting a new thread where you can talk about speaker styling and model names as much as you want.

Haven’t you just proved my point?

The thing is, you’re pretty disdainful about most of the choices people on this forum make -- most modern speakers are rubbish; buying new from a shop is a waste of money; a DD turntable is the only proper hi-fi source: OK, I’m exaggerating, but not by much.

Then when someone makes a criticism of your choices (e.g. my entirely uncontroversial comment about euphonic distortion), you get defensive.

That was the point of my obviously OTT rant about your speakers. Though in fairness, I did perhaps overdo it a smidge. Still, it was fun.