Just read the Fremer review of the Ypsilon Hyperion...interesting

[morricab]

you mean the Ypsilon's impedance deviation, poor sine wave, and high distortion in the bass don't matter? as an SS amp with no OPT?

SS without feedback does not have inherently low distortion...in fact they are less linear devices...it's physics. I guess I thought you knew that. The sine wave is not poor and the distortion is largely 2nd order and mostly < 1%, which by all accounts is inaudible. The output impedance is relatively high...for SS but not for a tube amp...again due to no feedback. Transistors are not so low in output impedance...unless you apply feedback. Bass distortion is also not so high, around 1%, which will likely be inaudible since it is mostly 2nd order at low frequency...a range we are not so sensitive to.

You take the feedback off most SS amps and get ready to watch a horror show of measurements because their inherent linearity is so poor.

 

[awsmone]

SS without feedback does not have inherently low distortion...in fact they are less linear devices...it's physics. I guess I thought you knew that. The sine wave is not poor and the distortion is largely 2nd order and mostly < 1%, which by all accounts is inaudible. The output impedance is relatively high...for SS but not for a tube amp...again due to no feedback. Transistors are not so low in output impedance...unless you apply feedback. Bass distortion is also not so high, around 1%, which will likely be inaudible since it is mostly 2nd order at low frequency...a range we are not so sensitive to.

You take the feedback off most SS amps and get ready to watch a horror show of measurements because their inherent linearity is so poor.

+1

Clearly having no nf is a deliberate design choice

The question is not that it measures well but how it sounds

I own the Lamm M1.2 they have NF not much but u can see the bend in the graph indicative of nf

Clearly Ypsilon are not fools, the question is were their design choices are successful in the SQ, MF seems to indicate yes

 

[KeithR]

SS without feedback does not have inherently low distortion...in fact they are less linear devices...it's physics. I guess I thought you knew that. The sine wave is not poor and the distortion is largely 2nd order and mostly < 1%, which by all accounts is inaudible. The output impedance is relatively high...for SS but not for a tube amp...again due to no feedback. Transistors are not so low in output impedance...unless you apply feedback. Bass distortion is also not so high, around 1%, which will likely be inaudible since it is mostly 2nd order at low frequency...a range we are not so sensitive to.

You take the feedback off most SS amps and get ready to watch a horror show of measurements because their inherent linearity is so poor.

You probably also tried to defend the Wavac measurements. Face it, sometimes stuff sucks.

The bigger issue is this is a 400W SS monoblock that is "designed" to drive tough speakers - why on earth would that be satisfactory looking at these measurements. it will become a completely voiced sound, which is exactly what JA conveys.

 

[morricab]

You probably also tried to defend the Wavac measurements. Face it, sometimes stuff sucks.

The bigger issue is this is a 400W SS monoblock that is "designed" to drive tough speakers - why on earth would that be satisfactory looking at these measurements. it will become a completely voiced sound, which is exactly what JA conveys.

Can you say based on the measurements if something will suck?? I think you cannot... I can tell if it has a chance to sound good or not...hint: it is not based on low THD, which Geddes showed has NO correlation with sound quality. His plots in fact showed a slight negative trend...although not statistically significant.

Have you heard either amp? Can you say, "Oh I hear that 0.4% 2nd harmonic ", which would be inaudible even with a pure sine wave let alone actual music. The amp delivers well over 200 watts of power under 1% THD, more than enough for nearly all speakers and rated power at a still perfectly acceptable 1.4%...as long as it is relatively monotonic distortion.

 

[opus112]

Transistors are not so low in output impedance...unless you apply feedback.

This isn't correct for any transistor in the common-collector configuration. In such a topology feedback is intrinsic, internal to the transistor and it therefore comes with a low output impedance. By far the majority of transistor amps use this configuration for the output stage. A small minority use common-emitter, with applied feedback.

 

[morricab]

This isn't correct for any transistor in the common-collector configuration. In such a topology feedback is intrinsic, internal to the transistor and it therefore comes with a low output impedance. By far the majority of transistor amps use this configuration for the output stage. A small minority use common-emitter, with applied feedback.

I guess it depends on what is considered low output impedance. The Hyperion would still be low compared to most tube amps.

 

[microstrip]

You probably also tried to defend the Wavac measurements. Face it, sometimes stuff sucks.

The bigger issue is this is a 400W SS monoblock that is "designed" to drive tough speakers - why on earth would that be satisfactory looking at these measurements. it will become a completely voiced sound, which is exactly what JA conveys.

I think this is the main issue. No one knows exactly how the amplifier will sound considering the measurements - we know that there is very little correlation between typical magazine measurements and sound quality in the high-end. JA in the past has been aware of this fact, commenting on technical issues, writing some warnings and raising questions, but always avoiding such strong negative statements. Why this behavior this time?

 

[awsmone]

I think this is the main issue. No one knows exactly how the amplifier will sound considering the measurements - we know that there is very little correlation between typical magazine measurements and sound quality in the high-end. JA in the past has been aware of this fact, commenting on technical issues, writing some warnings and raising questions, but always avoiding such strong negative statements. Why this behavior this time?

I don’t have a problem with JA s comments which is a cautionary note, perfectly reasonable given the price , the measurements are what they are

But the sound the sound the sound ... is what counts!

MF was most enamoured.... with experience and a top notch system, he didn’t know the measurements when he listened

I do believe it was once said

If you haven’t heard it, your opinion is irrelevant

 

[microstrip]

I don’t have a problem with JA s comments which is a cautionary note, perfectly reasonable given the price , the measurements are what they are

But the sound the sound the sound ... is what counts!

MF was most enamoured.... with experience and a top notch system, he didn’t know the measurements when he listened

I do believe it was once said

If you haven’t heard it, your opinion is irrelevant

We will soon have the review of Jacob Heilbrunn in the The Absolute Sound. He liked them enough to give them a Golden Ear Award. Quoting from TAS http://www.theabsolutesound.com/articles/2017-golden-ear-awards-jacob-heilbrunn/:

" The transparency, detail, and delicacy of this amplifier are indeed quite divine, but its ability to control the bass also rivals, and may even exceed, some of the most high-powered purely solid-state designs. The depth of soundstage is stunning and the treble region is seldom less than seductive. If you’ve always yearned for high power, but shied away from it for fear of sacrificing refinement on the altar of high wattage, the Hyperion may prompt you to think again."

 

[KeithR]

Can you say based on the measurements if something will suck?? I think you cannot... I can tell if it has a chance to sound good or not...hint: it is not based on low THD, which Geddes showed has NO correlation with sound quality. His plots in fact showed a slight negative trend...although not statistically significant.

Have you heard either amp? Can you say, "Oh I hear that 0.4% 2nd harmonic ", which would be inaudible even with a pure sine wave let alone actual music. The amp delivers well over 200 watts of power under 1% THD, more than enough for nearly all speakers and rated power at a still perfectly acceptable 1.4%...as long as it is relatively monotonic distortion.

Our own DDK has said the Wavac sounds as it measures. And I don't agree with you that spewing loads of 2nd harmonic can entirely be masked (nor does JA based on his comments in that review either) - and that's based on my personal in-house experience on a 101db speaker.

200 watts isn't nearly enough for many speakers. Unfortunately you believe your own predisposition which is : no NFB (and usually SET) is awesome no matter what. And there are plenty of SS amps without NFB that measure better.

 

[KeithR]

I think this is the main issue. No one knows exactly how the amplifier will sound considering the measurements - we know that there is very little correlation between typical magazine measurements and sound quality in the high-end. JA in the past has been aware of this fact, commenting on technical issues, writing some warnings and raising questions, but always avoiding such strong negative statements. Why this behavior this time?

That's fine - since you are a pure subjectivist.

Its quite easy to see from measurements that as power is increased, so is distortion so the last speaker you'd want to put on a pair of these is an insensitive one.

 

[KeithR]

I don’t have a problem with JA s comments which is a cautionary note, perfectly reasonable given the price , the measurements are what they are

Exactly - for a 93k amp that people on this forum would automatically assume can work on any speaker.

 

[microstrip]

That's fine - since you are a pure subjectivist.

Its quite easy to see from measurements that as power is increased, so is distortion so the last speaker you'd want to put on a pair of these is an insensitive one.

Surely I am a subjectivist, but not "pure". Since long I know "pure" objectivism does not bring anything of value to the high-end. I try to keep a balanced position between measurements and listening findings. It is why I reacted about such negative excluding comment.

Should I remember that an "insensitive speaker" is a vague and general concept?

Exactly - for a 93k amp that people on this forum would automatically assume can work on any speaker.

IMHO if anyone automatically assumes that one amplifier, irrespective of price, can work on any speaker, he still has a lot to learn about the high-end. Surely YMMV.

BTW, is there any positive reason behind any pure objectivist spending his time reading and debating a 93k amplifier? In the end it seems to me we are all subjectivists!

 

[Al M.]

In the end it seems to me we are all subjectivists!

+ 1

 

[awsmone]

Here is another hybrid with no NF
https://www.stereophile.com/content/aesthetix-atlas-power-amplifier-measurements

The main difference seems to be the interstate transformer which probably gives ultrasound peak and poor squarewave

Ypsilon Aelius 1

JA notes it’s unusual topology will be like a tube amplifier

https://www.stereophile.com/content/ypsilon-aelius-monoblock-power-amplifier-measurements

The squarewave performance is quite different

 

[morricab]

Our own DDK has said the Wavac sounds as it measures. And I don't agree with you that spewing loads of 2nd harmonic can entirely be masked (nor does JA based on his comments in that review either) - and that's based on my personal in-house experience on a 101db speaker.

200 watts isn't nearly enough for many speakers. Unfortunately you believe your own predisposition which is : no NFB (and usually SET) is awesome no matter what. And there are plenty of SS amps without NFB that measure better.

Maybe the Wavac sounds like it measures...so what?

The amp does not spew loads of second harmonic and yes quite a lot can be masked, regardless of your feelings on the matter.

My point about JA's comments is that they seem unusually harsh when compared to some recent SET or tube amp measurements that are objectively worse.

What planet are you on? 200 watts for a 90db speaker will play very loud without a doubt.

Please show me some pure SS amps that have no feedback.

 

[awsmone]

Please show me some pure SS amps that have no feedback.

see above ....well both r hybrid as is the Hyperion....

 

[bonzo75]

Here is another hybrid with no NF
https://www.stereophile.com/content/aesthetix-atlas-power-amplifier-measurements

The main difference seems to be the interstate transformer which probably gives ultrasound peak and poor squarewave

Ypsilon Aelius 1

JA notes it’s unusual topology will be like a tube amplifier

https://www.stereophile.com/content/ypsilon-aelius-monoblock-power-amplifier-measurements

The squarewave performance is quite different

The Aelius does not do drive and bass well. At least one soundlabs and in two vivid G1 set ups, and in one compared to the Luxman. The lux additionally had better Midbass, fullness, stage

 

[Folsom]

Old Luxmans are very pleasurable but maybe not what most audiophiles want.

I am rather curious what the linear distortion levels are on the Ypsilons and LM3s (cant find comments in reviews that would inform me). I know they are pretty bad on the 458's. It is just something I am very sensitive to, and the first thing I judge - most people dont even notice but "microdynamics" are an ok way to describe it but not often described correctly.

I cannot really tell by the review if I would like these or not.

 

[morricab]

see above ....well both r hybrid as is the Hyperion....

Exactly, they are hybrid; however, the Atlas looks to have at least some local feedback in its design based on the stereophile data.