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Old 4th April 2008, 10:28 AM   #541
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Default My biggest concern would be noise at idle (as I listen to my NAD 216's hissing away)

Rob, The 10 transistor boards from the original design which I have, and listen to quite often, do not make any noise at all with my ear right next to the speaker. The board layout, design and choice of components for this project produces an amplifier good enough that I sold off my Mcintosh equipment and replaced with these Leach amps --- except the MR-78.
You would not have to populate the board with anymore output devices than you need to drive your particular speakers. The On Semi 4281 devices are not cheap and if you match them leaving out a few could save a tidy sum.

BOB,
Did I read your last post correctly where you have the files for ONE complete board with frontend/output together? Tad
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Old 4th April 2008, 12:36 PM   #542
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Not quite Tad -- I have separate files for each board for production.

In addition, Jens combined the front end board and the extended output board into one panel to take maximum advantage or the $33 special. That way we can get 5 prototype boards (minimum order) for $132 + shipping + $50 multiple part fee instead of having to pay $132 + shipping twice. It saves $100 in prototype costs.

The front end and super amp output combination adds up to 62 in^2 with a 60 in^2 limit for the special.

On a down note, the gerbers were generated without part numbering on the silkscreens. I've asked Jens to regenerate them, but he may be busy for a while.

Professor Leach's boards didn't have part numbers. While not impossible to build it is a bit more tedious. I've put the prototype boards on hold until we know whether we'll be able to get part numbered silk screens.
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Old 4th April 2008, 02:05 PM   #543
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sorry but I am confused
Are there going to be designed additional front end regulated supply board
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Old 4th April 2008, 02:27 PM   #544
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Sam -

Jens will not have time to do another regulator board for this project. There is another group buy of his PSU2.2 brewing, see the WIKI. It can be scaled to higher voltages. I've got a set scaled to 65V with a parts list on my web page.

There will be one front end board, specifically a super amp. If you compare the Low TIM and Super amp schematics, you'll see that by omitting a few parts and placing a few jumpers you can convert a super amp front end to a standard low TIM.

Hope this helps.
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Old 4th April 2008, 04:16 PM   #545
rob3262 is offline rob3262  United States
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Default The On Semi 4281 devices are not cheap

I smell another Group Buy...
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Old 5th April 2008, 06:41 AM   #546
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Quote:
Originally posted by BobEllis
Not quite Tad -- I have separate files for each board for production.

In addition, Jens combined the front end board and the extended output board into one panel to take maximum advantage or the $33 special. That way we can get 5 prototype boards (minimum order) for $132 + shipping + $50 multiple part fee instead of having to pay $132 + shipping twice. It saves $100 in prototype costs.

The front end and super amp output combination adds up to 62 in^2 with a 60 in^2 limit for the special.

On a down note, the gerbers were generated without part numbering on the silkscreens. I've asked Jens to regenerate them, but he may be busy for a while.

Professor Leach's boards didn't have part numbers. While not impossible to build it is a bit more tedious. I've put the prototype boards on hold until we know whether we'll be able to get part numbered silk screens.
hi all, I'm at the hospital at the moment - My wife gave birth to our first child 3 days ago......everything is fine.

Ill see what I can do when we get home!
///Jens
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Old 5th April 2008, 08:18 AM   #547
loek is offline loek  Netherlands
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Default child

Hi Jens, congratulations with your child, sun or daughter?
Take your time for the family, thats more important at the moment.
Cheers, Loek
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Old 5th April 2008, 08:33 AM   #548
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Default everything is fine

Jens, I am very happy for you and congradulations to a new DAD. TAD
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Old 5th April 2008, 11:32 AM   #549
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Congratulations and best wishes to all your family.
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Old 5th April 2008, 12:34 PM   #550
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Congratulations Jens and Mrs. R! But, as the saying goes, without pictures there is no project

Psst! [whisper] You might want to be sure she doesn't catch you posting on this board for the next few days. [/whisper]

Seriously, Jens, don't rush. We can wait. You have MUCH more important things to do at the moment.

//Bob
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