[jonwb]

I recently purchased the SB3 and power supply components from nicksgem10s (http://www.audiocircle.com/index.php?topic=41722.0). 

I have a couple quick questions about the power supply construction that I'd like to run past you guys.

First, I'm assuming the fuse .5A would go on the hot lead between the IEC connector and the transformer.  Is this correct?

Second, w/ the supplied bits there is 3 feet of Mundorf cryo'd gold/silver hook up wire.  I'm not sure the gauge, but it is similar to that found in CAT5 network cable.  Any ideas on where I would use this wire?  From the PS to the DC jack?  And/or on the AC side too?

Oh, one more question.  Should I run/use a ground wire to/with this box or not?

Thanks,
Jon

[richidoo]

Small gage wire connects PS to SB. Check polarity with a voltmeter against the stock PS before you plug it into the SB!  Use copper solid wire as jumper on the PS settings. PM me if you need help with this, hopefully the Condor instructions are better than the Power-One versions, but it is still easy. Use a Switchcraft #760 plug to connect to SB (copper quality plug - cheap from mouser.com). Use quality solder, like silver eutectic if you have some - not critical for PS.

Ground the aluminum frame of the power supply along with the metal chassis to the mains ground. Everything metal should be very securely grounded together. Bolt the ground connections to frame/chassis with lockwashers, double nuts, circle connectors not spades. Don't skimp here. Solder the hot and neutral to the transformer leads.

Fuse goes on hot.

I use a similar PS made by Power-one. That is an awesome PS you have, with the 3A version. You will love it and will hear a big improvement over the switcher. Eventually think about getting a nice DAC for it, like Altmann DAC.

Have fun, and be careful!! (Double check that polarity so you don't  )
Rich

[jrebman]

John,

Yes, fuse the hot lead between AC inlet and transformer.

2.) The Mundorf wire is 24 AWG so you probably don't want to use it on the AC side.  Depending on how much you have, I'd probably run it from the reservoir caps or voltage regulator out to the umbilical connector.  If you have enough for a triple-braided umbilical, try that with the single wire hot and the others, ground, but most likely you 'll still want to shield the umbilical and terminate the shield at the ground connection at the PS end of the umbilical.  I may give this a try myself with my Welborne supply.

3.) Grounding is up to you -- my Welborne supply doesn't use any grounding, and most likely you'll be better off with no ground connection to the chassis.

Just my opinions, of course and other's advice will surely vary.

-- Jim

[Wayne1]

First, I'm assuming the fuse .5A would go on the hot lead between the IEC connector and the transformer.  Is this correct?

Second, w/ the supplied bits there is 3 feet of Mundorf cryo'd gold/silver hook up wire.  I'm not sure the gauge, but it is similar to that found in CAT5 network cable.  Any ideas on where I would use this wire?  From the PS to the DC jack?  And/or on the AC side too?

Oh, one more question.  Should I run/use a ground wire to/with this box or not?

Thanks,
Jon

The fuse should be wired in between the hot pin of the IEC and the transformer,

The SB3 can draw a little over 1 amp with the display on full brightness.

In theory, 29 awg and larger wire can handle this amount of current.

I prefer to use a bit larger gauge for the power supply. Typically 18 to 20 gauge.

For safety reasons, I would suggest you run a wire from the case to the IEC ground.

[mgalusha]

I connect the IEC ground to the chassis for safety as well but I don't connect the DC output ground to the chassis.

[jonwb]

The fuse should be wired in between the hot pin of the IEC and the transformer,

The SB3 can draw a little over 1 amp with the display on full brightness.

In theory, 29 awg and larger wire can handle this amount of current.

I prefer to use a bit larger gauge for the power supply. Typically 18 to 20 gauge.

For safety reasons, I would suggest you run a wire from the case to the IEC ground.

Thanks for the reply Wayne and mgalusha...

I think the fuse(s) I have are .5A.  I'm (obviously) not too electrically savy, but I do know that .5A on the 120VAC side is worth more than .5A on the 5VDC side (I should look more closely at the fuse and see the voltage rating).  Assuming that's true (of course not knowing what the efficiency of the PS is), do you think the .5A fuse I have is adequate?

I'm not sure what the exact gauge of the thin (supplied) wire is, nor am I sure for what purpose it was intended.  I was just thinking of using it between the PS and the jack in the enclosure w/ something thicker on the AC side.  Perhaps even between the PS unit and the SB unit.

Jon

[jrebman]

Thanks for the reply Wayne and mgalusha...

I'm not sure what the exact gauge of the thin (supplied) wire is,

You're welcome. :

If you don't believe me when I tell you it is 24 AWG or .5 mm, you can always call cryo-parts.com and ask Lee.  I just bought 20 feet of it today.

[jonwb]

I think I'm going blind... 

For some reason I didn't even see the replies from Rich and Jim!  Thanks guys! Very good tips.

I should have the switchcraft plug(s) on Monday.  I have the end plate for one of my boxes machined.  Turned out pretty good.  Of course its a bit of a pain cutting the hole for the IEC connector, but the aluminum is pretty easy to work with.  I'll post some pics probably next week when I finish one of the units.

Thanks,
Jon

[mgalusha]

I think the fuse(s) I have are .5A.  I'm (obviously) not too electrically savy, but I do know that .5A on the 120VAC side is worth more than .5A on the 5VDC side (I should look more closely at the fuse and see the voltage rating).  Assuming that's true (of course not knowing what the efficiency of the PS is), do you think the .5A fuse I have is adequate?

Yes and I'd go with a slow blow. The only thing (other than failure) that will normally cause the fuse to blow would be the inrush of current at turn on, hence the slow blow.

If the SB was drawing 1A@5V, which it will, this works out to about .1A on the AC inlet. This assumes the secondary winding voltage is about 12V, a 10:1 voltage and 1:10 current reduction from the AC to the DC output. Of course that would be if everything were 100% efficient, which it won't be but even at 50% you're only looking at 200mA current draw from the mains.

Mike

[jonwb]

Well I finished one of the two power supplies.  Here are a couple pics:





Sorry the pics are so small.  I tried to shrink them for the good of AC and ended up shrinking them too much and overwrote the originals.  Anyway, the build was pretty straight forward.  The trickiest part really is putting the holes in the case so it still looks respectable.  This particular PS is destined for my Dad.  He is using it w/ a stock SB3.  So I didn't use the fancy silver wire in his.  I tried it w/ my Bolder modified SB2.  It worked great right off the bat.  I used 16ga. stranded copper wire on the AC side.  I used a pair of 24ga (I think) wires from CAT5 cable for each GRND & +5VDC.  Output is steady at 5.026VDC. 

Its sounds quite good.  All I have to compare it to is a slightly upgraded ELPAC type unit I had been using.  That unit worked notably better than the stock wallwart, but I was wondering if I was meeting my SB2's potential as that PS was a 1A unit.  This new PS (3A output) seems to give me a bit more weight.  The sound has more body.  The highs seem cleaner and the hole sound stage seems more dynamic.  I'm anxious to get the other one built for myself w/ the silver wire and probably something a bit fancier for the DC cable.

Thanks again for the advice guys.  I'll post some better pics of the other unit once I get it built.

[JoshK]

What size extruded did you use?

[jonwb]

What size extruded did you use?

Some rough measurments (outside):  (W) 5-3/4 x (L) 8 x (H) 2-3/4

To be honest I'm not sure where nicksgem10s bought the cases from, but the Condor supply fits in there quite well.

Jon

[JoshK]

Thanks...I have one of those corcoms and I am too lazy to measure it.   

[nicksgem10s]

Nice work Jon.  That came out way better than if I would have attempted it.

I was directed to ebay for the aluminum case for the project which I found from the seller with ebay id

abakuscom

It looks like he still has some for sale.  This makes me want to try the project again.

I look forward to hearing about how your 2nd one turns out.  Thanks for sharing your pictures and experience.

Great Job.

Nick

[jonwb]

Nice work Jon.  That came out way better than if I would have attempted it.

Thanks! 

It looks like he still has some for sale. 

Yep, here's the link. 

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=230144275971

The Condor supply fits in there pretty well.  The trick is getting it spaced up off the bottom the correct amount (the Condor PS does not have a flat bottom).  I used a bunch of washers stacked up to get the height just right.  As you can see there is some flexibility w/ the location in the box; I more or less centered the transformer in the middle so it would be evenly weighted.  FWIW, the box is warm to the touch when its plugged in. 

Josh if you have the same Condor supply I would snag one of those cases if I were you.  Good size and the end plates are made of a pretty soft aluminum which makes the machining easier.  I laid out the end plate holes in AutoCAD and printed it out 1:1 scale, taped it to the end plate itself and then used a center punch through the paper template to mark the hole centers for the DC connector and fuse holder.  For the IEC connector I cut out of the paper template the shape (based on my measurements) and used a marker to trace it onto the plate.  Then I drilled a bunch of holes to get the bulk of the mat'l out of there and used a small end-mill bit on a machine we have a work to clean up the hole to size.  I then put the connector in the hole, squared it up and used the connector itself to mark its screw holes (then center punched them for drilling). 

Sorry for being so long winded I just thought this info might help if someone wanted to do this... the Condor supply looks to be getting a little harder to come by.  Here are a couple links:

http://www.alliedelec.com/Search/ProductDetail.asp?SKU=744-0089
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=320078446947

Jon

[crooner]

Condor PS units are excellent. Your finished unit looks very nice.

I'm using a medical grade 12A version on my latest PS.

With some tweaks here and there it bests my earlier 3A supply.

[F-100]

Well I finished one of the two power supplies.  Here are a couple pics:

Hey Dude,
  Your PS sure looks like mine. Are they twin brothers???

[F-100]

Condor PS units are excellent. Your finished unit looks very nice.

I'm using a medical grade 12A version on my latest PS.

With some tweaks here and there it bests my earlier 3A supply.

Crooner,
  That is some serious PS you got there. What are those 3 black things on the right side of the picture. Are they ferrite beads?? How much improvement do you notice on this one over your old Power-One PS?

[lonewolfny42]

So....which one works better ?

Hey Dude,
  Your PS sure looks like mine. Are they twin brothers???

[F-100]

So....which one works better ?

Hey Dude,
  Your PS sure looks like mine. Are they twin brothers???

That is a tough question. 

My PS have some upgrade parts (Elna Cerafine & Blackgate caps) so I think I have an edge over his stock Condor.