[andyr]

Mmmm, this is a very interesting thread which has had some heavy input ... which I would say I am not competent to engage with but, since Bill dragged my name into it (I'm not aware of another AKSA "Andy" owner, Bill?), I guess I will throw a few currants into the dough!  

You're it Andy.  The reason I mentioned you is that I know you actually design and listen to amps.  This is not to slight others, people like Kyrill, who obviously have a lot of experience with tweaking and listening, and whose posts I also enjoy, and opinions I respect, it is simply the name that came to mind when I penned my post. 

Thanks
Bill

Alas, Bill, I must tell you that I do not design amps ... only CF-composite subchassis for the LP12!   

I don't need to design amps - I have a mate who does that for me!     But I have been fiddling around with DIY hifi for 35 years and do listen a lot!   

Regards,

Andy

[bhobba]

The reason the singer moved forward when the amplifier was changed seems fairly straightforward to me.  The higher output impedance of the SET amplifier interacted with the complex impedance load of the speaker and boosted the midrange relative to the other amp.  I actually think that would be easily measurable.  Am I wrong?

Your explanation may be correct - or may not be.  Scientifically possible explanations should always be checked experimentally.  I would say the situation is rather complex, and more experimentation needs to done to get to the root of it.  Witness how long it took Hugh to create the LifeForce.  If I read what he writes correctly, he believes even greater improvements are possible.

Thanks
Bill

[bhobba]

No matter how much one thinks is objective we are still influenced by our biases. Is it the speaker or the amp contributing 50% or 90% to the quality  sound. How can you really tell.How can you really be sure unless you test it out properly. Is it not how things work together and how this black art of successful combination is mastered that's important. Great amps, top speakers and sources can still sound crap if they do not complement each other . Its how we coax out the full potential of each component as a whole which is most important but  eludes most of us.
A cutting edge amp and speakers can be made to sound exceptional and can be made to sound bad. A crappy amp and speakers will more than struggle  to sound cutting edge.

Is this what this discussion is all about because I was not entirely sure

My intent in posting was to simply chronicle my changing views on audio.  It has, understandably, since it touches on issues at the core of the subjectivity vs objective debate dear to the heart of many audiophiles, generated a fair amount of discussion.  Which is good - IMHO.  At least I find the the responces illuminating and of value regardless of exactly what position a person takes in the debate.  As to issues of blind listening in audio, despite Peter Aczels characterisation of John Atkinson as a 'black hat', he has written what I think are relevant and lucid articles on it:
http://www.stereophile.com/features/113/index.html
http://www.stereophile.com/asweseeit/705awsi/

Of particular interest to me is the discounting of the facts by those that claim blind test after blind test has shown all amplifiers sound the same.  The tests they tout as proving their position simply do not do that:
'The next step in the analysis was to see if it made any difference in responses whether the amps being compared were the same or different. It sure did! The data in Table 3 show that a difference was correctly identified over 64% of the time, but that sameness was correctly picked only about 38% of the time. This difference in results, at these numbers of responses, is way, way beyond the possibility of chance ("highly significant," in statistical terms). Of further interest, Adcom first, followed by VTL, was slightly better identified than the other way around (see Table 2). However, when there was no difference, it didn't make any difference which was the same, Adcom/Adcom being misidentified as often as VTL/VTL. Although there was again some inter-session variation in the specific proportion of correct responses to the four possible amplifier pairings, none of it went much against the overall trend.'

The fact such evidence is ignored is, to me, quite interesting.

Thanks
Bill

[LM]

My intent in posting was to simply chronicle my changing views on audio.

Bill, so was mine in my initial response and yes the danger of any response is the near certainty that polarized discussion will ensue.  My main point was that early on I accepted the general ‘rule of thumb’ on faith that amps didn’t matter much and I simply don’t accept that any more.

Steven makes the extremely valid point of the room being a major influence in the sound.  Could not agree more but my 40/40/20 was a relative weighting (my opinion) assuming those components as variables in a fixed room.  This I guess is always a problem in forum responses, what I had in my mind about the room I did not really convey.

Likewise, Theo makes the point of a well-matched system as a whole being bigger than the sum of its components.  Again I totally agree and maybe that’s why individual components such as the amp can have such a significant effect (to me) when swapped, seemingly out of proportion to what makes sense against the traditional view.

Finally Andy, I take your point about music being primarily emotional and that emotion being a primary differentiator, absolutely.  However, that was not quite the point I was meaning to convey in my example.  Some people look at those ‘spot the differences’ puzzles for ages, can’t see any and swear (until shown) that ‘there are no differences’.  If they learn to ‘scan’ segments progressively, they will pick up the differences in no time.

This is rather the same thing I’ve found in listening to ‘pick the differences’.  Whilst it is a great way to judge the overall emotional impact you talked about, if I listen to the musical piece as a whole, I can rarely use this to tell one component from another.  I might judge that the system has shortcomings rather than a specific component.  If however, I focus on specific areas such as base V treble, or the spatial relationships between instruments, tonal discrimination etc, the aural differences (if any) are then a lot easier to discern between components.  Whether you call that training or experience, the more I worked on my listening the better I got at discriminating.

Which brings me to the final point.  At the end of the day, picking or thinking that you can pick minor differences is totally irrelevant for the sake of it unless it helps you positively get to a final pleasing balanced system.  To me, listening and then making up my own mind is far more important than all the specifications, reviews or DBT results in the world regardless of their worth as a guide.  It doesn’t matter if I’m right, wrong or delusional, I only have to satisfy me.

[AKSA]

Lyn, Bill,

Thanks for your very interesting insights.

Bill, you raised a comment I had earlier made here:

...he believes even greater improvements are possible.

I think it's inevitable, and I think the benefits will be chiefly in that impossibly vague area of musicality, or engagement, if you will.  Every week now I see new topologies appearing on the net, discussed briefly, then discarded because they are old news.  Recently I saw something very interesting, a pure current drive to the voltage amplifier, which I believe could have legs.  But until I or someone else builds it, then we will never know.  There is such a gulf between what we believe we know and what is actually available, and known.  There are still a few think my Glass Harmony is the best amp I've done (tube front end, SS mosfet SE output stage), but personally I think the Soraya is the best by quite a margin.  I live in hope I'll get better and better.....

But, as one wise sage remarked recently, even if its the best amp in the world, the trick is to get the buying punters to actually care, and then make the purchase!!

Cheers,

Hugh

[gerado]

Hi Bill
I agree with the sentiment of your arguments completely.  I hope I did not come across otherwise. This is a great topic and educational to hear so many varied opinions.
I may not be standing at the same spot you are on everything at this point of time but as you correctly stated one can change their stance depending of further experience and good counter reasoning and evidence. Every one is correct if it works for them. Fun is the ultimate aim of the game.

I havent read your links, but will soon, always interested in varying points of view and information.
Fixed and dismissive attitudes I am not keen about , but it is still interesting to listen and try and understand why people have such strong views.

Where I stand presently. I think ones expectations influence the perception of what they hear more than any physical factors. I have fallen for this and still do. Enter a lovely, furnished room, with prior knowledge of very expensive equipment that you probably always lusted after,  brands of distinction, and odds on you will walk away feeling impressed. However live with it for months , let the shine come off and listen to a lot of alternative set ups and then you start hearing holes in the whole set up. Whats happening here? Is it Lyns dots in the sky concept coming into play , a true improvement in appreciation through learning or that anything new half decent always sounds better. Personally I think its the former, otherwise Im stuffed ,briefly happy but chronically dissatisfied.
Through a short time and a lot of exposure I think I have learned to recognize and dissect out of the equation the expectations I form a lot earlier than I used to, but still sucked in initially for a time nevertheless. Others like Lyn, Hugh and Andy (who I owe a lot for their help in my re education ) can cut through it all much faster.

A good design(not always related to cost: note LF100 ) should always reproduce the source signal faithfully if that was the design intention. How it sounds to different individuals will depend on preferences and expectations.

I have no idea if its 60/20/20, 40/40/20 or what ever other combination weighing in contributing to sound quality and my enjoyment. All I know is I can spot the differences between equipment and sometimes spot differences when there are none!

.....and we havent even touched cables and line conditioners yet

[andyr]

.....and we havent even touched cables and line conditioners yet

Nor even how one solid-core wire will sound different, one direction to the other!      

Regards,

Andy

[Davey]

PM received.

Sorry, I didn't realize the "Glass Harmony" amplifier actually has a solid-state output stage.  It's a bit confusing to call an amplifier with a transistor output stage a Single-Ended Triode. 

Dave.

Dave,

The Zout of the SET 'Glass Harmony' is 50 milliohms, down there with conventional global fb SS. 

I've PMed you on the other matter, which I won't discuss any more here.

Cheers,

Hugh

[kyrill]

so the question still remains, no

[Davey]

Yep, shot down again.

Well, at least I had a theory. 

Dave.

[bhobba]

Well, at least I had a theory. 

And keep coming up with theories - just realize they need to be checked from experiment.  My theory on why the glass harmony sounds so good is that negative feedback in an amp needs to be used judiciously.  Too much, while reducing distortion further, will mean it can not respond to transients as quickly, and can make amps sound 'lifeless'.  Valves have inherently greater linearity in the usual voltage range put out by preamps than solid state devices, and require less feedback.  The higher output impedance can be corrected by a transistor of FET voltage follower with low output impedance allowing the valve to operate optimally.  Such setups require little or no overall feedback, relying mostly on local feedback in the valve input stage, and voltage follower. While I think it is a reasonable explanation it does need to be checked experimentally.

Thanks
Bill

[AKSA]

Dave,

Yes, I second that from Bill, at least you tried.  And you were not shot down, not by a long, or a short, shot.  I appreciate your input, in fact.

I don't know the answer either, if that's any consolation.  But the imaging on that amp is extraordinary, though not as sharp as the Soraya.  I had one listener, a German with a great love for Thelonius Monk, who would sit for hours in front of the GH with a beatific smile on his face.  He LOVED that amp!  But I could only play them on a cool day.

I never did sell the Glass Harmony commercially, tricky to make, and hugely inefficient (150W of heat for 28W of audio    ), so I don't feel too bad about the SET false advertising.  In truth, about 90% of the sonic qualities devolve from the 6SL7 front end, which is t-barred, runs at a combined 3.2mA with B+ of 340V.  Once you know the phone number of a tube, you can really bring out the sonics......

Cheers,

Hugh

[kyrill]

Hugh: " Once you know the phone number of a tube, you can really bring out the sonics......"

I have received my sleeve matched NOS ECC189 / 6ES8 SIEMENS   X 5

and the first 2 sounded after 12 hrs play equal to the Siemens CCA !!
very deep sound stage, musical and utterly relaxed very much better than the original stock
and i paid 28 UK pounds for 5 pcs.

The GK-1 was not designed around the 7308 or CCA so the NOS 6ES8 is a winner

One but.  this is  observed by my ears on very mediocre speakers although i bypassed the tweeter cap with
Vishay Roederstein MKP1837   0,01mF MKP 100VDC – 1% tolerance
but these speakers could discern differences between stock, e88cc e188cc CCA and now this one
But still there must be more subtle differences the kitchenspeaker cannot distinguish

So the designer of the GK-1 knows the phone number of the 6ES8 
but a tube not* very appreciated in audio land
*at this very moment ZERO for sale on Ebay and zero on Audiogon

with such low sales there must still be 1000-ands in boxes somewhere or in dustbins

[Davey]

Well, obviously some experimentation might have revealed some clues.  Speculating is fun because it's....speculating. 

However, I think if you turned me loose with both amps and the speaker system that was used I could have come up with the answer.  Most of that type of thing is measurable...if you know where/how to look.

Dave.

[AKSA]

Dave,

If we assume that you did not set out to insult me, can I ask: 

How much money do you have invested in measurement equipment, in retail dollars?

There is a price of admission, and I'd be interested to know just how much.

Cheers,

Hugh

[Davey]

What is it with you Hugh?  You think...again...I'm taking a cheap shot at you?

This type of defensive posture doesn't become you.

If you must know, I have access to tens of thousands of dollars worth of test equipment via my workplace.  I have some on my test bench at home too.  Would you like an itemized list?

Dave.

[AKSA]

Davey,

This is the issue;  the high cost of measurement equipment.

I have a 100MHz Tek CRO, several DVMs, function generators and a simple Leader distortion meter.  These were all purchased used to save money, so I rely heavily on listener tests as well as the basic measurements.

Since relatively few of the measurements one commonly sees in high end spec sheets directly correlate with sound quality, and things like FR and linearity can be divined fairly easily with CROs and simple voltage/current measurements, I choose to avoid use of advanced distortion analysers because I don't believe, for me at least, they are worth the money.

I don't believe you are aware just how confrontational you sometimes appear in this forum.  This may be due to the sterile medium which fosters misunderstandings and slights, but in any event, let's forget it and get on with fruitful discussion.

I'm deeply involved in a really tricky SMD layout at present, and it's driving me bananas.  Do you have any experience in such matters, perhaps you could help?  I'd appreciate some professional input as I'm taking too much time and stabbing in the dark too much for my liking.  It's mostly 0805 Rs and SOT26 chips.

Cheers,

Hugh