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Old 4th November 2012, 07:52 PM   #1
Einric is offline Einric  United States
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Default LM4780 Dual Parallel Project

Hey everyone I am finally getting started on my LM4780 Dual Parallel project.
I have gone with AudioSector LM4780 kits and will be running them on a single power supply.
I am running an Antek AS-2224 Toroid, I know the voltage will be a little high but I have been running on a chip in stereo on it for about a year without any issues and a MUCH smaller heatsink.
I am currently deciding on power supply setup, CRCLC or 10kuf "snubberized" with additional 10kuf tank capacitance at the amp boards.
The project is progressing slowly but well.

Any thoughts about my power layout?
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Old 4th November 2012, 11:25 PM   #2
AndrewT is offline AndrewT  Scotland
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Peter must be tossing in his sleep at your suggestion of using his kit in this manner !
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Old 4th November 2012, 11:44 PM   #3
Einric is offline Einric  United States
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Why do you say that Andrew?
I haven't decided how I am going to use my power supply yet.
I may do the CRC or I may do just tank capacitors at the board rail input.
I just don't know yet.
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Old 5th November 2012, 09:15 AM   #4
AndrewT is offline AndrewT  Scotland
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Audiosector, run by Peter, has a philosophy of only using at amplifier smoothing and only using relatively low values of electrolytics here.
A bit like oversized MF decoupling right at the amplifier, where most would use 100uF to 220uF, Peter advocates around 1500uF for best overall sound quality.

But he does not use conventional smoothing capacitance at the transformer/rectifiers.

Your proposed arrangement is completely at odds with Peter's philosophy and yet you have bought into his product.
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Old 5th November 2012, 12:30 PM   #5
Einric is offline Einric  United States
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I have bought his product and love it very much.
I'm trying to build an amp that will not be touched after this assembly.
That being said I would like a stiff supply with very low ripple and energy storage.
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Old 12th November 2012, 05:37 PM   #6
Einric is offline Einric  United States
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Default Chassis & Layout

Here is my loose chassis and layout.
What do you think?
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Old 28th November 2012, 02:23 AM   #7
Einric is offline Einric  United States
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Default Chassis Frame Completed

The chassis frame has been completed.
Here is my final layout.
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File Type: jpg 100_1841.jpg (578.7 KB, 236 views)
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Old 1st December 2012, 03:23 AM   #8
Einric is offline Einric  United States
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Default Top & Bottom Installed

The top & bottom are installed with spacing for ventilation.
The bottom is 1/8" Diamond Plate and the top is .093" PlexiGlass.
I put the top on spacers for ventilation.
The diamond plate is installed with the tread upward.
This allows for an evenly spaced gap all down both sides for good natural cooling.
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File Type: jpg Bottom Diamond Plate.JPG (330.2 KB, 55 views)
File Type: jpg Top Spacer.JPG (389.9 KB, 29 views)
File Type: jpg Chassis Finished.jpg (508.2 KB, 45 views)
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Old 1st December 2012, 07:15 PM   #9
Einric is offline Einric  United States
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Default Rear Panel Completed

I was lucky enough to get my cut for the IEC Socket to work out perfectly.
I had to use my bandsaw to make the cutout because my 50's Dremel scrollsaw just wouldn't cut 1/8" aluminum.
Luckily enough the opening cut with the bandsaw is completely covered by the bottom bezel of the IEC Socket.
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Old 1st December 2012, 09:05 PM   #10
Einric is offline Einric  United States
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Default Silicone Thermal Pad

I have some of these silicone thermal pads recovered from a dead amp.
Are you required to use thermal compound with them?
The amp I pulled them off of had no thermal compound.
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