Measurements & Sound Quality

[mansr]

3 minutes ago, DuckToller said:

Frank,

which are the measurements you find necessary and sufficient for good sound???

Number of solder joints.

[Ralf11]

I will third, that Nelson Pass is both honest and forthright.  I have an old Adcom... maybe should get a Threshold too?

 

If I were to take time off from other things, I'd DIY one of his designs myself.

[fas42]

6 minutes ago, DuckToller said:

Frank,

which are the measurements you find necessary and sufficient for good sound???
Tom
 

 

If I knew that, I would sell it as a product ... .

 

Unfortunately, I'm relying on my ears as much as anyone here who chases optimum sound - another lifetime, perhaps I'll get around to it, .

 

As implied in mansr's response, it's detecting the influence of poor integrity of the overall system, which in part is caused by poor standards of some connections. So, there would be some sort of signal correlated noise present which needs to be measured - this would be certainly possible to detect; it just needs to be researched to come up with an ideal test signal.

[Jud]

35 minutes ago, jabbr said:

 

Nelson Pass is honest. Minimal BS. It is terrific that he can be open about his designs, provide his schematics for hobbyists and make money at the same time. We need more of this. He deserves every penny he makes and more. If you can solder and follow directions, you too can build one of his amps. If you can't then you can pay $$$$. Or get an old refurbished Adcom. Seems very fair to me.

 

Though to be absolutely fair, he doesn't release the current commercial designs.  But a not very old Pass amp for a fairly low cost is an excellent deal.

[sandyk]

10 minutes ago, Jud said:

 

Though to be absolutely fair, he doesn't release the current commercial designs.  But a not very old Pass amp for a fairly low cost is an excellent deal.

 Hi Jud

 The cost would be prohibitive for DIY people to construct Nelson Pass's big Class A monoblocks for example, given the marked discounts he would obtain for quantity purchases of components, transformers, metal work etc. even if he did offer the designs.

 Then of course, his designs would be exploited by Asian manufacturers, even if he stipulated non commercial use only of his intellectual property.

 

Regards

Alex 

[Jud]

15 minutes ago, sandyk said:

 Hi Jud

 The cost would be prohibitive for DIY people to construct Nelson Pass's big Class A monoblocks for example, given the marked discounts he would obtain for quantity purchases of components, transformers, metal work etc. even if he did offer the designs.

 Then of course, his designs would be exploited by Asian manufacturers, even if he stipulated non commercial use only of his intellectual property.

 

Regards

Alex 

 

Not really. If you look at the DIY Audio thread for the X amps, which were reasonably recent Class A commercial designs, I believe prices being discussed a few years ago were in the range of $400/channel for monoblocks, slightly less for stereo.

[crenca]

2 hours ago, Jud said:

 

Since measurements are more accurate than the ear, I wonder what "tweaks" are needed.

 

Off the top of my head I don't remember - I recall watching a couple of interviews on Youtube where he explains his design method and use of measurements a year or two back.

 

edit:  this might be one, but the one I am really thinking of was at least an hour I believe:  

 

[crenca]

2 hours ago, Jud said:

 

Since measurements are more accurate than the ear, I wonder what "tweaks" are needed.

 

Oh, I don't believe it is useful to say that measurements are more "accurate" than the ear, or vice versa.  Different domains.  I think you can only correlate statistically.  Perhaps a psychoacoustic guy will chime in...

[sandyk]

12 minutes ago, Jud said:

 

Not really. If you look at the DIY Audio thread for the X amps, which were reasonably recent Class A commercial designs, I believe prices being discussed a few years ago were in the range of $400/channel for monoblocks, slightly less for stereo.

 Hi Jud

 I meant the big Class A monoblocks. i.e. 100W/ Channel for example.

 I have heard these, and they are quite big with substantial heat sinks and metal work ,as you would expect due to the large power output in Class A.

 Even my own 15W/Ch. Class A amplifier dissipates almost 100W of heat, so imagine the heat from these beasts in Summer .

Regards

Alex

[jabbr]

2 hours ago, Jud said:

 

Though to be absolutely fair, he doesn't release the current commercial designs.  But a not very old Pass amp for a fairly low cost is an excellent deal.

 

Who else releases schematics of older designs, let alone current? 

 

$400/channel might almost get you the case, then there’s heatsinks, transformers, yeah maybe the electronics are about $400 in volume  

[STC]

The cost of a highly praised amp....?

 

A recent comment by someone who did some trouble shooting on the unit. 

 

“Cost of components and manufacturing <£250.  Cost of hype £4,750.  EMC shielding = 0.  Summary = rubbish......”

[fas42]

2 hours ago, crenca said:

 

Oh, I don't believe it is useful to say that measurements are more "accurate" than the ear, or vice versa.  Different domains.  I think you can only correlate statistically.  Perhaps a psychoacoustic guy will chime in...

 

Far from "a psychoacoustic guy", but as someone who has twigged onto this term relatively late in the day - the way the brain reacts to annoying anomalies is where the real action is. My first bit of kit that performed well had "all the right measurements", which is initially why I was happy to buy it - but certainly didn't stand on its hind legs straight out of the boxes. I spent plenty of time listening to all the kit that was around back then, and I was reassured that my choices were good, even in their raw state - and then that situation progressed to a continuous cycle of learning exercises, where I would become aware of slight flaws in the sound, and tried things, to see if I could eliminate what I heard as not being quite right ... then, one day ...

[Jud]

2 hours ago, sandyk said:

 Hi Jud

 I meant the big Class A monoblocks. i.e. 100W/ Channel for example.

 I have heard these, and they are quite big with substantial heat sinks and metal work ,as you would expect due to the large power output in Class A.

 Even my own 15W/Ch. Class A amplifier dissipates almost 100W of heat, so imagine the heat from these beasts in Summer .

Regards

Alex

 

Alex, there was (may still be) an incredibly thorough website by a Pennsylvania professor who built a couple of these. The fellow also was active in the DIY Audio thread about this amp.  Yes, these are the big ones.  The price may or may not have been exclusive of case, but as I recall there were people who managed to get sources for those that weren't too bad either.

 

I'm at a holiday party at the moment, but will see if I can find links, perhaps tomorrow.

[kumakuma]

30 minutes ago, fas42 said:

 and then that situation progressed to a continuous cycle of learning exercises, where I would become aware of slight flaws in the sound, and tried things, to see if I could eliminate what I heard as not being quite right ... then, one day ...

 

Your doctor prescribed Clomipramine for your OCD?

[Sal1950]

I tip my hat to Nelson Pass, he is very open about his designs, shares a lot of knowledge, etc. He's described a bit of his sound goals for the different lines of amps, how he has circuits tuned to produce different end results, etc. Unlike many of both manufacturers and lay audiophiles, he doesn't hide the fact the it isn't all about High Fidelity but more about producing a sound that is pleasing to a particular group of listeners. IMHO he is a pro's pro when it comes to understanding measurements and relating them to a sound type. Measurements can tell you everything you need to know about how a component will or does sound, you just need the knowledge and experience to figure that out.

[fas42]

OCD? Is that what they call an interest in debugging, these days?

[diecaster]

23 minutes ago, Sal1950 said:

Measurements can tell you everything you need to know about how a component will or does sound, you just need the knowledge and experience to figure that out.

 

What measurements, exactly, tell you how a component will or does sound? Please provide the whole list.

[fas42]

Just noted this,

 

Quote

Fundamentally, what interests me most about amplifiers are the differences in sound created by different topologies and the characteristics of the active gain devices.

 

, from https://www.stereophile.com/content/nelson-pass-circuit-topology-and-end-science.

Immediately tells me I wouldn't be interested in his designs, because he's chasing an active tone control - just insert the right weakness, to add the required flavouring ...

[kumakuma]

6 minutes ago, fas42 said:

OCD? Is that what they call an interest in debugging, these days?

 

I was thinking more of your posting history here on this site.

[Jud]

37 minutes ago, Sal1950 said:

Measurements can tell you everything you need to know about how a component will or does sound,

 

I'm thinking I may have read Nelson Pass saying something more along the lines that Crenca mentioned Andrew Jones saying, that final adjustments might be done with the aid of ears.

[Jud]

1 hour ago, Jud said:

 

Alex, there was (may still be) an incredibly thorough website by a Pennsylvania professor who built a couple of these. The fellow also was active in the DIY Audio thread about this amp.  Yes, these are the big ones.  The price may or may not have been exclusive of case, but as I recall there were people who managed to get sources for those that weren't too bad either.

 

I'm at a holiday party at the moment, but will see if I can find links, perhaps tomorrow.

 

http://www.facstaff.bucknell.edu/esantane/movies/aleph-x.html#Version

[Sal1950]

23 minutes ago, Jud said:

 

I'm thinking I may have read Nelson Pass saying something more along the lines that Crenca mentioned Andrew Jones saying, that final adjustments might be done with the aid of ears.

If my post made it sound like I was attributing that comment to Mr Pass, that was a mis-communication on my part. That sentence was strictly MHO. 

[Sal1950]

45 minutes ago, diecaster said:

 

What measurements, exactly, tell you how a component will or does sound? Please provide the whole list.

lt would be much easier for you to get a EE degree yourself. No one could supply that level of information in a simple forum post.

[jabbr]

31 minutes ago, Jud said:

 

http://www.facstaff.bucknell.edu/esantane/movies/aleph-x.html#Version

Great article!

[diecaster]

18 minutes ago, Sal1950 said:

lt would be much easier for you to get a EE degree yourself. No one could supply that level of information in a simple forum post.

 

No, I want to know which tests you think tell us how an amp will sound.