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Old 16th November 2003, 03:04 PM   #1
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Location: Toronto, Canada
Default My humble A30

Hi all,

I completed this about a month ago. I finally managed to borrow
a digital camera to snap a few pictures.

But first, a big thank-you to Mr. Pass for sharing with us his
wonderful designs and his tremendous support to the DIY community.
Many thanks also go the other members of diyaudio who provided much
technical guidance and inspiration. (Too many to list here!)

This is my first completed project and it has been a great learning
experience.

I stuck close to the original A30 schematics. The only significant
part substitution I made was the use of IRFP044's for the output
devices, since I already have some on hand.

The PS uses a 500VA, 2x20 transformer with four 62000uF filter caps
and the rails are at +/-25V. The heatsinks are 11x11 pieces from
the R-theta group buy. PCB's are based on Mark Finnis' designs
(Thanks Mark!) DC offsets are 35mV (R) and 25mV (L).

And yes, I did use blue LED's

Cheers,
Dennis
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Old 16th November 2003, 03:06 PM   #2
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Default one from the inside...

Warning: Messy construction ahead!
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Old 16th November 2003, 03:10 PM   #3
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Default ...and one from the back...

I had trouble soldering the copper Cardas binding posts
so I ended up using these. (I couldn't get the solder to
flow properly. Any suggestions?)
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Old 16th November 2003, 03:21 PM   #4
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use a slightly higher wattage soldering iron..the copper somehow acts like a heatsink and draws the heat away...which might be why your solder is not flowint well...or maybe u can try tinning your wire and the binding post before actually soldering the whole thing in...
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Old 16th November 2003, 08:22 PM   #5
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Very impressive,

You have taken real pride with this project and its well engineered.

It deserves a 5 star rating *****.

Ian

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Old 16th November 2003, 10:14 PM   #6
B.L. is offline B.L.  Poland
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I am looking at power supply...

1. broad copper plates for lower impedance (?)
2. resistors for higher impedance (?)

inconsistency?
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Old 16th November 2003, 11:09 PM   #7
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The copper is a convenient means of a conductor for mounting on the capacitors. The resistors are the CRC filter to reduce the AC ripple.

The pics on the X Aleph thread (page 38-41) by Mr Pass of the XA 200 show a similar arrangement.

Ian
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Old 17th November 2003, 12:36 AM   #8
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any luck trying to solder the posts?? I hate to see a good amp with a lousy binding post...
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Old 17th November 2003, 01:51 AM   #9
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Great Job Dennis!!

How's it sound?

WRT the Cardas posts, as li_gangyi said, get a higher wattage iron and tin the solder cup at the end of the post first.
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Old 17th November 2003, 01:55 AM   #10
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I got all of them to solder well with a 50W iron which I borrowed from my Dad...I only have a 25W one...I guess it will also do the job...but with more time...
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