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Old 10th September 2006, 03:41 AM   #1
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Default Completed LM3875

This is from an old Yamaha CD player from a mate which I stripped. Put a new front panel on with some perspex. Then painted and inserted a 20mm LED, Why i call it BT1(bad taste) as everyone was using mini super bright blue LED's i wanted something different.
Tranny is 300VA 25-0-25, with two bridged rectifiers 35amp 400v.
Two rails of filter caps: 10,000uf ea.
4.7uf 50v Elna at the front of each rail
100nf 275v at the end of each rail.
Sanded some plumbing nuts down with some wet & dry then drilled and counter sunk them for the screws and used them for the feet.
10mv & 5mv DC offset, so pretty happy.
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Old 10th September 2006, 03:42 AM   #2
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Default More Pics

Here is a pic of the power supply

EDIT: The caps are 22nf 1000v poly's
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Old 10th September 2006, 03:46 AM   #3
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Default Filter caps

These were put into a 25mm block od perspex. They go all the way down. There is a white perspex plate at the bottom. the rails were made up from enamelled copper wire which i had to scratch away at the corretc distances(Boring )

EDIT: The bleeder resistors are 20w 6K8
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Old 10th September 2006, 03:48 AM   #4
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Default Amp

These were the easiest of course I made sure of my earthing. placed a .5ohm resisitor and a 220nf cap in the earth path.
Mybe it's over-kill, but it is quiet.
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Old 10th September 2006, 03:52 AM   #5
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Default feet

A pic of the feet
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Old 10th September 2006, 07:57 AM   #6
owen is offline owen  United Kingdom
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Looks great, nice attention to detail


Owen
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Old 10th September 2006, 08:26 AM   #7
Nuuk is offline Nuuk  United Kingdom
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Agreed, that's good work with attention to detail and plenty of thought put into it too.

But how does it sound?
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Old 10th September 2006, 08:50 AM   #8
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Default Sound

Nuuk..........sounds great. this is the third LM3875. I had just finished a dual mono LM4780, but was not happy with the sound. It had heaps of power and 40,000uf of filter caps as well, but i think these LM3875's do sound better. I had to try the LM4780, just to see if there was a difference. I think this chip is slightly more cleaner sounding

The LM4780 gives a great punch but lacks the subtleties and the finesse of the LM3875, oh s......t i don't know, it just sounds better

Anyway I'm very happy with the sound
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