Another fun build. Driver and phase splitter. - Page 4 - UK Vintage Radio Repair and Restoration Discussion Forum

Radio Wrangler · 14th Apr 2014, 2:39 pm

Back in the late 60's and early 70's the designers at the main audio companies thought they knew it all as did the readers of Wireless World, Hifi News and Record Review etc.

Amplifiers were produced with vanishingly low amounts of distortion, flat frequency responses and low noise. What more was there to do?

Some listeners were not happy though with many amplifiers. What's more they could reliably tell the good 'uns from the bad 'uns by ear. So there wasn't any tomfoolery. The listeners were right. The designers were wrong.

Subsequent investigatio showed that some amplifiers behaved very badly indeed when slewing fast. Some would stick a while if clipped. They did noce numbers on sinewave tests, but showed failings on real programme material.

I first came across this through discovering Matti Otala's designs for a well-behaved amplifier. Subsequent designs fixed the problems.

What we're left with is a lingering folklore which says all measurements are bad and that the best ears can hear things the best instruments can't detect. Quite a number of people subscribe to it. On top of this there is a ready supply of charlatans and snake oil merchants cashing in on it, as well as a lot of innocent victims of the emperor's new clothes syndrome.

A reasonable approch is to recognise that both ears and instruments have told us important things in the past, to recognise that instruments are not good if they're not being used to measure the right things, to recognise that human perception is highly suggestible and that one can lead oneself up the garden path even if there is no snake oil merchant to do the job.

Listening is good, but it does take careful conditions to eliminate suggestion. Measurement is good, but it does take care to interpret results. and to be sure that measurements are comprehensive.

It took both views to get us the good stuff we have today.

It only took a number of snake oil merchants to get us the high priced silliness we also have. My offer to show TubeGlow how Leaks, Quads and ST70s were designed was real and well-intentioned. (And still stands)

Hey Kalee... I think you may just have created a rationale which could be used to sell directional resistors

David

David

David

14th Apr 2014, 2:39 pm	#61
Radio Wrangler Moderator Join Date: Mar 2012 Location: Fife, Scotland, UK. Posts: 22,858	Re: Another fun build. Driver and phase splitter. Back in the late 60's and early 70's the designers at the main audio companies thought they knew it all as did the readers of Wireless World, Hifi News and Record Review etc. Amplifiers were produced with vanishingly low amounts of distortion, flat frequency responses and low noise. What more was there to do? Some listeners were not happy though with many amplifiers. What's more they could reliably tell the good 'uns from the bad 'uns by ear. So there wasn't any tomfoolery. The listeners were right. The designers were wrong. Subsequent investigatio showed that some amplifiers behaved very badly indeed when slewing fast. Some would stick a while if clipped. They did noce numbers on sinewave tests, but showed failings on real programme material. I first came across this through discovering Matti Otala's designs for a well-behaved amplifier. Subsequent designs fixed the problems. What we're left with is a lingering folklore which says all measurements are bad and that the best ears can hear things the best instruments can't detect. Quite a number of people subscribe to it. On top of this there is a ready supply of charlatans and snake oil merchants cashing in on it, as well as a lot of innocent victims of the emperor's new clothes syndrome. A reasonable approch is to recognise that both ears and instruments have told us important things in the past, to recognise that instruments are not good if they're not being used to measure the right things, to recognise that human perception is highly suggestible and that one can lead oneself up the garden path even if there is no snake oil merchant to do the job. Listening is good, but it does take careful conditions to eliminate suggestion. Measurement is good, but it does take care to interpret results. and to be sure that measurements are comprehensive. It took both views to get us the good stuff we have today. It only took a number of snake oil merchants to get us the high priced silliness we also have. My offer to show TubeGlow how Leaks, Quads and ST70s were designed was real and well-intentioned. (And still stands) Hey Kalee... I think you may just have created a rationale which could be used to sell directional resistors David David David __________________ Can't afford the volcanic island yet, but the plans for my monorail and the goons' uniforms are done