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Post pics of your builds....

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Re: Post pics of your builds....

Postby cobretti » August 12th, 2013, 1:09 pm

Here is an update of my bench supply.
I did some noise measurements and here are the results. I have to say that I changed few components of its original design and also added my own components. Since there are multiple modules, supporting elements and wires running everywhere, sigma11 lost its original integrity so the results are worse from the original.
"Ti" wrote somewhere if I remember correctly that he was able to measure noise around 12uV.

Right channel is slightly worse but not bad:
voltages go from 5.6 11.2 16.8 22.4V

corresponding noise into 100 ohm resistor is: RIGHT channel 12.5 17.8 23 27uV
LEFT channel 8.6 13.3 17.7 20uV

The worst noise I obtained with 50 ohm load resistor at 22.4V was 38uV

Not bad at all I think.
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Re: Post pics of your builds....

Postby cfcubed » September 7th, 2013, 6:48 am

Another β22 lives. I've a thing for heat-sinks & compact builds and these cases fit the bill. They're high quality, have good ventilation and reasonable cost when ordered in multiples.

b22_2ch_front_stacked.jpg

b22_2ch_back.jpg

b22_2ch_insides copy.jpg


As a way to sort of justify getting a table-top CNC setup & learning to use it I'm building two of these same amps, one will go up for sale (probably where you make audio gone:) The engraving is light/subtle because I used a V-bit instead of the more difficult tiny end mills. Also made the ε12/pot/jack/Zobel network board (serving as star ground) & used screw terminals such that any module could be replaced w/o soldering. The power switch is rated @ 250VAC/5A, the umbilical is 3-cond 16 gauge (just fits in the 5A/300V-rated? DIN housings) and the amp's LED lights at ε12 latch. The newer AnTek transformer has an enhanced wrap & "static shield" purple wire to ground, hear no noise stacked even when using Alessandros (Grados).
Very pleased with the build, no surprise but far more work & time when into it then I'd expected/planned. I'll probably only be building the two.
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Re: Post pics of your builds....

Postby amb » September 7th, 2013, 12:54 pm

Fits like a glove! What case is that? And the power switch?
Very nice work!
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Re: Post pics of your builds....

Postby cfcubed » September 7th, 2013, 5:51 pm

Thank you Ti & thanks again for the β22 & other boards used in the amp and build support here & through your store.
Searching ebay for "2107 enclosure case diy" finds the case, I bought 4 at once (lowers the per case shipping fee) & again am very happy with the fit/finish/weight of them.
For power switch, search ebay for "led 19mm latching blue push switch -car", mine happened to be 24v LED supply ones - using resistors to σ22 + / - lines.
Yep the case/β22s/σ22 board fit is about perfect, I revised the ε12/pot/jack/Zobel board to be about 1/2" less deep for the next build, only a bit deeper than the ε12 board, freeing up a bit more room in the amp case.
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Re: Post pics of your builds....

Postby fishski13 » September 8th, 2013, 1:52 am

nice!
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Re: Post pics of your builds....

Postby mikeg88 » September 8th, 2013, 12:53 pm

I like how you made your own board to hold the offset protection circuit and the volume pot at the front of the enclosure. Also nice heat-sinking, and great all-around hardware implementation. Nice job!
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Re: Post pics of your builds....

Postby cfcubed » September 9th, 2013, 5:01 am

Thanks guys. With the over-kill, external heat-sinks amp gets only to "warm" at 140ma bias with most heat outside of case. The availability/price/quality/size of those off-the-shelf cases is what tempted me to go ahead w/CNC & building at least two of them.

WRT front panel/ε12 board - Thanks, yeah like the least # of wires & within-case wiring and don't care for Molex KKs (haven't the proper tool) hence the screw terms.

A small CNC setup is something that's always tempted me & once one's in the house & you're somewhat proficient you're on the prowl for projects for it. So far about 1/2 its projects were related to this (front/back panels, heat-sink mounts, front panel/ε12 board), the other 1/2 things around the house - perfectly round holes are no problem as long as within its work envelope. Still new & learning but its great fun. Posted some of my experiences under same user ID here: http://www.microcarve.com/forum/showthread.php?tid=224
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Re: Post pics of your builds....

Postby Mullet » October 19th, 2013, 8:09 pm

I figured since I used the Sigma 25 in one of my projects I'd put forward my achievement. I used 3 Sigma 25s in this project. 1 Supply was used as 5v power to the DAC board and to an Isolation/Re-clocking board. The other 2 supplies were used to create a bipolar supply of +15v 0v -15v for the buffer section of the DAC. It was a world-wide project. The components came from the US (Amb Sigma 25s), Italy (Amanero USB 384 board), Australia (Acko AKL AMN-S01 Isolator and re-clocking board) and Germany (Curryman ES9023 with Joachim Gerhard Buffer). Finally, the chassis was built in Oregon, US. I slapped everything together and made it work. By the way, it sounds great! Could I have used Sigma 11 instead for the DAC/Reclocking? Sure, but I wanted to keep the footprint down. I'm sure the Sigma 11 would have performed better, but how much would my tin ears notice it? Not really sure. Enjoy the pics!

Image

Image

Image
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Re: Post pics of your builds....

Postby kt88 » October 20th, 2013, 7:49 am

RGB leds? :D

What case is it?
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Re: Post pics of your builds....

Postby Mullet » October 20th, 2013, 9:04 pm

Whassamatta with the RGB LEDs? I work in the TV biz so I have an affinity to those colors.

The case was bought on eBay from 01robo. I actually had him do the chassis to a custom size. His childhood buddy was previously making the chassis, but had a sudden demise. So 01robo decided to continue making the chassis in memory of his friend.

Just curious... as a side thing I had a machinist do the drilling for me. I don't currently have the tools or space to do it. He wanted to continue offering his services and wanted to know what people would pay for drilling holes to spec including square holes for the IEC socket / USB port.
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