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Old 6th Dec 2017, 10:00 am   #38
GrimJosef
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Join Date: Sep 2007
Location: Oxfordshire, UK.
Posts: 4,311
Default Re: Leak Stereo 20 and TL12 Plus in need of recommissioning. Help and Guidance needed

Quote:
Originally Posted by Radio Wrangler View Post
Back in the day of the Leak amps, basic quality resistors were +/-20% tolerance.
10% tolerance parts got a silver band. 5% parts "High stab" got a gold band and that was about it. You didn't dare to ask what their drift over time was like. These percentages were simply how accurate they were at time of manufacture. 2% was for very special parts in measuring instruments ...
The whole of the above post is a very good one. Just one minor clarification - as I understand it the gold band was only for 5% tolerance. 'High stab' meant that the resistance value was stable over time. This commonly involved a different form of construction (e.g. carbon film versus carbon composition) and was indicated by an additional salmon pink band. When I come to restore a vintage piece of kit one of the more worrying signs is the sight of a lot of 5% resistors, so the manufacturer knew that they needed to be within a tight spec, but the absence of any salmon pink, so I now know that they no longer will be .

Cheers,

GJ
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