Sound Quality Vs. Measurements - Page 710 - diyAudio
Go Back   Home > Forums > Member Areas > The Lounge

The Lounge A place to talk about almost anything but politics and religion.

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 4th September 2012, 05:00 PM   #7091
diyAudio Member
 
Join Date: Mar 2007
Location: Oxfordshire
I discovered H C Lin after being told that Harold Leak firmly told either Mr Tobey or Mr Dinsdale he would see them in court if they were so foolish . They were indignant that his amplifier resembled an article in Wireless World by them . He then added " I am very rich , who is going to win " ? No doubt none of it true ? However it got me looking at who did invent quasi complimentary amplifiers . As Douglas Self points out Tobey and Dinsdale seem to forget Mr Lin when accepting praise . Mr Lin himself mentions a colleague who inspired it . Lin got the biasing sorted out .

One story I know to be true is Mr Leak was approached over a weekend whilst the staff were at a hi fi show . Apparently he was crying the Monday morning afterwards . It had been bought for the then fortune of 3 000 000 over that weekend . Rank bought it . Apparently one of their staff loved hi fi . They were rich with Xerox money . Soon they abandoned the almost military standard of testing . Then surprise surprise reliability suffered . Next it was given to Roland Electronics / Rotel . The source of this Alan Tisdale who was his right hand man . Leak was a significant company . Out of the ashes was born Rotel as we know it , albeit not directly . Naim copied Leak almost to a tee , the way of testing espeacailly .

I am no lawyer . I can see T&D had no chance . The famous RCA amp with LTP ( Naim , Harman Kardon ) is called modified Lin . No offense to T&D and I accept the story is most likely untrue . The Byran amplifier was unmistakably theirs .

Oral History Lin Index RCA Germanium Transistors Audio
https://www.youtube.com/watch?v=49He8QwlAU0
Bryan Amplifiers - Anyone have any Information? - pink fish media
  Reply With Quote
Old 4th September 2012, 07:27 PM   #7092
gpapag is offline gpapag  Greece
diyAudio Member
 
gpapag's Avatar
 
Join Date: Nov 2002
Location: Athens-Greece
Quote:
Originally Posted by bcarso View Post

*Analog Circuit Design, Art, Science, and Personalities".
Thank you Brad

George
__________________
["Second Law is a bitch." - SY] ["The Road To Heaven:Specify the performance & accept the design. The Road To Hell:Specify the design & accept the performance"-Bruno Putzeys]
  Reply With Quote
Old 5th September 2012, 07:40 AM   #7093
dvv is offline dvv  Serbia
diyAudio Member
 
Join Date: Sep 2004
Location: Belgrade, Serbia
Quote:
Originally Posted by nigel pearson View Post
... Soon they abandoned the almost military standard of testing . Then surprise surprise reliability suffered ...
It doesn't take much to understand just how important testing is. Especially now, in this "brave" new world.

About 3 years or so ago, Wima, te German quality capacaitor maker, realized that they were going off the board. Their response was immediate - they reduced the size of their caps, they reduced the prices by quite a bit (if memory serves, they slashed off around 45% of the original price), but they also slashed they warranty, down from 2 years to 6 months.

Since I use a lot of their caps in my products, this was a mixed bag for me, and I believe others using their products as well. On the one hand, slashing prices like that is not good, not great, but stupenduous good news, but on the other hand, cutting their warranty is all bad news. I offer a 5 year warranty for my products, and now I beging to doubt one of my key suppliers. You don't just wake up one morning and say it's a great day, let's slash prices today.

So we (me and my associates) discussed it, and frankly, we were a little scared. We decided to extend our 48 hour or 2 day test period to 7 days. Statistically, if it works for 7 days under high load conditions, and comes out with its guaranteed minimum specs all above the norm, chances of its failing in the field are extremely small.

So what we saved on the price of the caps, we paid for extended testing, new test racks, etc. But we all still sleep soundly. In 11 years of operation, only one unit ever failed, and even that was traced back to a power amp which relied on fuses for "protection" - the amp burned, the fuses remained intact, in all fairness, the amp's fuses AND our internal fuses. Frankly, this is something I am very proud of.

We test components when they come in, not 1 in 100 or 1,000, but 1 in 10. We test and measure individual filter boards and we test the finished product. Sure, it costs time, space and money, but at least we are sure we are selling a fully functional product which works as specified. It does cost money, but we all, and especially myself, feel its money well spent. No buts, no ifs, no maybes.

Leak was a company with a rock solid reputation for the longevity of their products, all of them. After Rank took them over, they very quickly went into oblivion, obviously the Rank people had no idea of how to run an audio company. Even more obviously, they went about it by cutting costs first, and the first victim was Leak's testing procedures, which were said to be second to none. The net result was a cheaper product line, which soon became known for its poor reliability. This sunk the company, and if I were Mr Leak, I'd cry too.

They tried to bring them back once or twice, for example by rebadging a Rotel integrated amp (which, in my view, looked way better than the Rotel version of it), but it never caught on.

Oddly enough, I knew all this when I started out in 2000, and Leak was one of the examples I always had in mind when extensive and sometimes cruel testing procedures were introduced. But we are a small operation, so our logistics are relatively simple, and I always justified them by saying we're in this for the long haul, so we have to pay maximum attention at all times. 12 years down the road, and I think we should extend our test procedures to hit the 10 year warranty period.
__________________
Per Aspera Ad Astra.
  Reply With Quote
Old 5th September 2012, 10:07 AM   #7094
diyAudio Member
 
Join Date: Mar 2007
Location: Oxfordshire
If you look at an early Leak amplifier nothing about it suggests reliability . Equally some of the hastily made Sony's look perfect and were not . Sony were replacing ranges very quickly in the 1980's , no time to spot long term problems . The point is Leak tested every component and every sub assembly . Then every complete product . Rank gradually took it down to testing 1 in 10 amplifiers . They even sort of blamed the UK production staff for problems . Funny part of the story is that Tony Morpath took over the remnants of the Leak branded Rotel disaster . He sold it as Rotel UK ( Game Path Ltd latter ) . I got involved as the first Flat Earther as we were called ( those who prefer turntables ) . I sold it when no one else would and thought the Stan Curtice design RA820 astonishing ( still do ) . Apparently Tony was told by Rotel to sell more or loose the brand . He calmly said he could sell less of the rubbish , but not more . He then said " shame as it is well made rubbish " . Rather than get angry Rotel said if you are so clever why don't you tell us what to make . Apparently the box , PSU and sockets was predetermined . The PCB was the UK bit . Tenuously Rotel came out out of Leak . Reliability of those Rotel is second to none at any price . Stan played a bass guitar through it as he thought if it coped with that it would cope with real music . We debated capacitor choice the other day . That's how Stan did it I'm told . It saved money . I think he said he was very short of budget and wanted a few special components . He redesigned the PCB many times so as to avoid wiring . That got him the money for the parts . It sold in the UK for 79 inc VAT and 25% dealer margin . That was the same price as the discount houses so I could even give students 10% . Fuses were 95% of the repairs . One output transistor a rare exception . I can still remember the bias as 43 mV through 0R22 .

When Rank took over Leak the prices tumbled . Alas so did the reputation . Some how it never recovered . Quad must have been delighted as Leak did what they did better and cheaper . Leak strongly resembled American Acoustic Research in no nonsense science .

I think if done with care Leak would be a brand worth restoring . In fact via Rotel would have been OK . It might even be possible to look at the point where the brand stopped and pretend a logical path of improvement took place over the years . If it were me I would even keep the all NPN output stages . I would also make the TL12 plus in revised form . A superb amplifier not unlike the Heath designs using EL 84 .

Naim did an exact copy of good Leak practice . Julian Vereker even said it saved money as 5% components would do . The tolerances were laid out in bins and paired . Exactly as prototype and no great cost . He once joked to me that Naim had the lowest profit of all UK hi fi companies . He then said , I do spend more on research than them .
  Reply With Quote
Old 5th September 2012, 11:38 AM   #7095
diyAudio Member
 
Join Date: Mar 2007
Location: Oxfordshire
All of you who think there has been progress in Audio listen to this . Where is the hiss ? Where is the distortion ( allow a little and flutter ) . This is a direct transfer and is only a fraction as in data compressed form . I never bettered it .

https://www.youtube.com/watch?v=MPSSx4jYEmg
https://www.youtube.com/watch?v=EY7lvuVjjX4

Use headphones if you can , not computer speakers .
  Reply With Quote
Old 5th September 2012, 08:49 PM   #7096
tvrgeek is offline tvrgeek  United States
diyAudio Member
 
Join Date: Dec 2009
Location: Md
But I have pretty good computer speakers. Mine of course.

I have heard worse. Where is the hiss? Front and center to me! 45dB maybe?
  Reply With Quote
Old 5th September 2012, 09:26 PM   #7097
diyAudio Member
 
vacuphile's Avatar
 
Join Date: Apr 2011
Location: Not where whatever I am looking for is at.
Nigel,

I was deeply moved by this recording, which, being the barbarian that I am, was utterly unbeknown to me. Thanks for posting it.

The technology in no way detracted at any point from the experience. That is quite something for 1944.

vac
__________________
Everything is somewhere. Where the @!#$ is it.
  Reply With Quote
Old 6th September 2012, 12:24 AM   #7098
a.wayne is offline a.wayne  United States
diyAudio Member
 
a.wayne's Avatar
 
Join Date: May 2008
Location: Front Row Center
Quote:
Originally Posted by Wavebourn View Post
No, I don't.
Quote:
Originally Posted by nigel pearson View Post
All of you who think there has been progress in Audio listen to this . Where is the hiss ? Where is the distortion ( allow a little and flutter ) . This is a direct transfer and is only a fraction as in data compressed form . I never bettered it .

https://www.youtube.com/watch?v=MPSSx4jYEmg
https://www.youtube.com/watch?v=EY7lvuVjjX4

Use headphones if you can , not computer speakers .
Fantastic recordings .......
  Reply With Quote
Old 6th September 2012, 01:02 AM   #7099
bcarso is offline bcarso  United States
diyAudio Member
 
Join Date: May 2005
Location: Canoga Park, California
Very impressive recording! And the music and performance ain't too shabby either!
  Reply With Quote
Old 6th September 2012, 02:02 AM   #7100
a.wayne is offline a.wayne  United States
diyAudio Member
 
a.wayne's Avatar
 
Join Date: May 2008
Location: Front Row Center
I cant believe that's a 1944 tape , how is that possible ...?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Quality Control differences = variations in sound quality? KT Class D 3 4th June 2014 12:02 AM
Sound Card for Measurements Marik Solid State 2 2nd January 2012 08:59 PM
Sound Card Recommendations (For Audio Measurements) dchisholm Equipment & Tools 5 16th July 2011 09:40 AM
How to protect sound card during amp measurements? okapi Everything Else 13 2nd September 2008 03:06 PM
Sound cards - test and measurements jackinnj Everything Else 2 5th July 2003 03:02 PM


New To Site? Need Help?

All times are GMT. The time now is 11:39 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2