The Audiophoolery Thread.

[greg_simons]

Originally Posted by Cathovisor

Propagation velocity is the speed at which a signal travels down a cable. The coax I worked with in the past was 2/3rds of the speed of light, so 5ns/metre. This stuff was significant in the days of analogue TV (especially colour) as it told you the delay between when a signal was sent and when it was received.

Knowing the "velocity constant" of a cable is useful when it comes to Time Domain Reflectometry, but that's a whole different kettle of bananas. Basically you fire an incredibly narrow pulse down an unterminated cable and see how long it takes to come back.

Cheers for that, I was half way there, as usual there's a nugget of real science there but I'm guessing the propagation delay across point seven of a metre of cable isn't significant at audio frequencies.
Greg.

[Julesomega]

QSA is the q-code for "What is the strength of (my) signals" - just sayin'

[Andrew2]

'a sonically-optimized solution'. Ye Gods, I've heard it all now.

[The Philpott]

I hadn't heard the term 'vapourware' before, but yes, i believe that the aforementioned fuses merely exist in someone's mind, rather than in the stores dept. I'm sure they would obligingly cobble one together if an order was made.

Considering that the domestic customer needs specified items insurance to cover any one item or collection that exceeds (for example) £1k-£2k.....such a fuse would effectively be uninsurable in the home, let alone in the mail.

Dave

[Radio Wrangler]

Originally Posted by greg_simons

but I'm guessing the propagation delay across point seven of a metre of cable isn't significant at audio frequencies.
Greg.

This is where the first law of audiophoolery comes in.... That there is no limit to the discrimination of an audiophool's hearing.

There is no proof of this assertion, but it is taken as read like any other religious bedrock. People can also get rather uppity if it is challenged.

From this root factoid, consequences flow.

If discrimination is infinite, then no effect, no matter how small, can be insignificant. Anything which can be imagined, which cannot be proven beyond any doubt to have absolute zero probability, is therefore significant.

Non-audiophools, lacking limitless hearing, do have thresholds below which they cannot hear. So audiophiles can hear things which mere mortals cannot, and those mortals consequently disbelieve all audiophile facts.

I think I'm getting the hang of this philosophy lark...

David

But, But.
How is it that the audiophools bang on about the sonic perfection of their 0.000001 THD amplifiers with its bowling green flat frequency response and are able to ignore the connected loudspeaker system shortcomings that measure distortion in whole numbers and have response graphs that look like the profile of a Toblerone.

(Other brands of lumpy honey flavour chocolates are available).

[greg_simons]

Originally Posted by Radio Wrangler

This is where the first law of audiophoolery comes in.... That there is no limit to the discrimination of an audiophool's hearing.

There is no proof of this assertion, but it is taken as read like any other religious bedrock. People can also get rather uppity if it is challenged.

From this root factoid, consequences flow.

If discrimination is infinite, then no effect, no matter how small, can be insignificant. Anything which can be imagined, which cannot be proven beyond any doubt to have absolute zero probability, is therefore significant.

Non-audiophools, lacking limitless hearing, do have thresholds below which they cannot hear. So audiophiles can hear things which mere mortals cannot, and those mortals consequently disbelieve all audiophile facts.

I think I'm getting the hang of this philosophy lark...

David

Wise words Master Po.
Grasshopper.

[Craig Sawyers]

A paper busting the myth of velocity of propagation at audio frequencies

http://audiosystemsgroup.com/TransLines-LowFreq.pdf

Craig

[Cathovisor]

Exercise for the student:

Calculate the phase difference at 15kHz introduced by 3.5ns of delay, both electrically and acoustically.

[Cathovisor]

Originally Posted by G.Castle

But, But.
How is it that the audiophools bang on about the sonic perfection of their 0.000001 THD amplifiers with its bowling green flat frequency response and are able to ignore the connected loudspeaker system shortcomings that measure distortion in whole numbers and have response graphs that look like the profile of a Toblerone.

(Other brands of lumpy honey flavour chocolates are available).

Or the direct opposite - a ratty old ex-radiogram amplifier (with no nasty negative feedback) built out of military surplus components with two Mazda triodes feeding a 1930s energised loudspeaker?

[Radio Wrangler]

Originally Posted by Cathovisor

Exercise for the student:

Calculate the phase difference at 15kHz introduced by 3.5ns of delay, both electrically and acoustically.

And then calculate how far you have to move your head to achieve the same effect. Students may assume 330m/second velocity of sound waves.

Added merit for comparing this with the stiffness of those wooden braces which victorian photographers used to keep their subjects still for the very long exposures they took, and derive the associated size of forces.

David

Originally Posted by Cathovisor

Or the direct opposite - a ratty old ex-radiogram amplifier (with no nasty negative feedback) built out of military surplus components with two Mazda triodes feeding a 1930s energised loudspeaker?

The problem with this particular type of Phool is that they will buy up a 1930s high end radiogram from an auction with its Pee Ex twenty fives and rape the amp/ power supply from it, and burn the cabinet without a second thought for the restoration work that had been lavished on it by a recently deceased owner.

Yes I know it was their money

If that sounds a very specific scenario that's because it is something that happened quite recently.

Originally Posted by Cathovisor

Exercise for the student:

Calculate the phase difference at 15kHz introduced by 3.5ns of delay, both electrically and acoustically.

Here's my answer:
My slide rule is broken and, the calculation is pointless.

[greg_simons]

Originally Posted by G.Castle

The problem with this particular type of Phool is that they will buy up a 1930s high end radiogram from an auction with its Pee Ex twenty fives and rape the amp/ power supply from it, and burn the cabinet without a second thought for the restoration work that had been lavished on it by a recently deceased owner.

Yes I know it was their money

If that sounds a very specific scenario that's because it is something that happened quite recently.

Horrific, maybe you could elaborate either here or another thread.
Greg.

OK. Here goes. If the moderators consider it inappropriate or in the wrong place I'm sure it will be moved or deleted as required:

Around ten years ago my parents were moving into a house in Kings Lynn, a large nineteen thirties built middle class home where you may not be rich enough to have live in servants, but probably still changed for dinner, which you ate in the evening, and in a separate dining room, while listening to music playing on your new radiogram.

Whilst the house was being decorated, a kindly elderly neighbour introduced himself and my parents and they and he became friends. The man's name was Roy Fenn, a retired bank manager, and an enthusiastic amateur electronics buff, who had been an RAF technician of some sort during the fifties and sixties.

On one occasion, when I visited my people, I had reason to call around to the house next door, it was an Aladins cave of quality furniture and a few pieces of period houshold equipment.

In what would have been described as the drawing room, stood a late nineteen thirties HMV radiogram, that I learned later was an 801AC: the old gentleman was most happy that the set had gained an admirer and told me about its features, how he had painstakingly restored the cabinet, redoing the veneers where damaged, and replaced failed components, rewound transformers, and generally brought it back up to near new condition. His voice was filled with pride as he told me all this, it was easy to see that this old radiogram was the love of his life.

I decided there and then I'd like to add the model to my collection of old and interesting ephemera.

Now these old things are almost as rare as hens teeth, but I did know of one, a Marconiphone version of the same instrument, that was owned by an old mentor of mine who now lived in Gloucester, his was however in a very poor unrestored state: he was in no mind to sell it though as it was going to be his retirement project.

Fast forward to 2020:

In an auction listing I found a marconiphone 801AC for sale, it was described as used "working" but in need of some cosmetic restoration. I put in a bid but there was however the problem of collection, plus the vendor was a rather sketchy character to say the least and ended up withdrawing the item. The vendor then made contact with me and said that I could have the set, and we negotiated a price, I wasn't holding out much hope of it being as described so that was reflected in what I offered, I sent my van driver over to the vendors place and told him not to hand the cheque over if it looked incomplete.

Unfortunately it wasn't anywhere near complete though looked so to my drivers untrained eye, and the original amplifier and turntable was missing, however the cabinet although slightly damaged was whole and a better basis for repair and restoration than my friends in Gloucester, so the remains were sent to him.

Now. More recently, due to my father's ill health I had to arrange for he and my mother to have bungalow accommodation. Whilst we were moving them out and preparing the house for rental, the old gentleman neighbour Roy, was visited on several occasions for various reasons and we struck up a rapport over our shared enthusiasm for all things vintage. I told him of my fruitless quest to find an 801AC. In his words, he said, "My boy if you want one, you shall have this one when I'm gone! Give me your full name and address and I'll put a letter with my papers to that effect and I'll give you a signed letter as well."

The inevitable happened at the end of last year, and Roy passed away, though as it turned out he had made 96 years old, and went quickly when it happened.

Unfortunately for the HMV, I did not find out about Roy's passing until mid February this year, and went on a quest to find out what had happened to the old radiogram, the solicitors who had closed his estate claimed that there were no letters attached to Roy's will, and the set had been sold at auction with several other items of furniture.

Enquiries with the auctioneer led me to the person who had finally bought the HMV, I was told off the record that the winning bid was £84: ironic really as the price of the set originally was 80 guineas or £84 in 1937.

I contacted the buyer, a Mr Marcus, with the intention of offering to buy the set from them, when I met with the guy, the owner of some kind of craft company, he listened to my story intently and at the end of it exclaimed that he wished I'd come a week earlier, as he'd "taken what I wanted out of it and burned the rest of the effer".

The beautiful cabinet, the radio chassis, the EMI K4 autochanger, and even two of the three speakers; and the full collection of original 78's all burned.

He even showed me the remains still in the place where it happened.

Roy had no children they say.

[The Philpott]

Thankyou. Have heard similar bad luck stories; usually involving fire or the scrap man, but sometimes involving theft or companies who have gone into administration/liquidation. Somehow even worse when you know something still exists but you can't get to it. In your case it probably made you wish you hadn't even managed to track down the buyer.

Dave

[Cathovisor]

Returning to something slightly more modern: I'm sure many of us are aware of how 'X' valve with a certain construction and a certain set of codes printed upon it is allegedly sonically superior to any other type - but does this apply to transistors too? Or does the easy "plug and play" of a valve lend itself more to this type of subjectivism than going in with a soldering iron and then proclaiming that a Fairchild transistor sounds better than an RCA one, for example?

[Radio Wrangler]

It's the plug and play aspect which makes valves so vulnerable to wine-tasting. If other components were to be swapped around, soldering irons would be involved and the doing of technical work. Some people proclaim that this is beneath their station, but in reality they don't want to expose their lack of skills.

Noting how some colours of markings on valves denote sonic superiority... valves with their original boxes also carry quite a price premium, so they must sound better. Consequently, the best audiophiles must be able to listen to your system and from what they hear, tell you whether or not you also own the original valve boxes!

David

[Cathovisor]

Originally Posted by Radio Wrangler

It's the plug and play aspect which makes valves so vulnerable to wine-tasting. If other components were to be swapped around, soldering irons would be involved and the doing of technical work. Some people proclaim that this is beneath their station, but in reality they don't want to expose their lack of skills.

Noting how some colours of markings on valves denote sonic superiority... valves with their original boxes also carry quite a price premium, so they must sound better. Consequently, the best audiophiles must be able to listen to your system and from what they hear, tell you whether or not you also own the original valve boxes!

David

If ever a post deserved a "like" button...

[knobtwiddler]

Originally Posted by Cathovisor

...does this apply to transistors too?

If you've looked at the 'Diy audio' group, you'll see plenty of amp building threads where people debate the sonic merits of transistors. I recently found an inspiring 10-page thread where, over a period of months, a member honed a design that used Hitachi MOSFETs. It was fascinating, as he updated it every few days, nibbling away at noise and overshoot until it looked like a good commercial design. On page 10, having dedicated weeks of time to it, another member came along and posted a diatribe against lateral FETs, saying how cold and lifeless they were subjectively, and how he'd wasted his time on the project. The OP (obviously a learned engineer), has never been seen at the group again...

You have to be thick-skinned to post at groups. That's probably why so few of the academically-inclined design engineers I know go near them. I take my hat off to Mr Stenning and his mods for keeping the cabbage throwing at a minimum here. It shows!

edit - to quote the great audio engineer Tim de Paravincini: 'electrons have no memory'.