SB power supplies?

lcrim · « **on:** 20 May 2006, 04:00 am »

Surfed over to the Slimdevices forum last night and found a thread that was basically a sales thread for a guy who is using that forum to peddle his power supplies. Seemed surprised that the Slimdevices guys weren't thrilled w/ the idea. He wants $175 and I expect its better than the switcher delivered w/ the unit but no idea how much better.
I've been using an Elpac unit from Allied that was a little DIY and $50 but was wondering about the hospital grade PS's. I use a SN Chibi Dac w/ mine so the analog mods don't really interest me but was wondering what others finally ended up with?

Occam · « **Reply #1 on:** 20 May 2006, 02:50 pm »

Larry,

Jabberwokkie simply bought the remaining stock of PowerOne 5v 3amps linear open frame supplies @$2.50ea from Cascade Surplus (and elsewhere), and put them in a Consite chassis. It slightly irks me that he denied other DIYers the opportunity to do their own at such low cost, but his lack of a clue is of more concern. In the week prior to the offer, he asked some rather basic questions as how to use them. And while those, and other surplus versions from PowerOne/InternationalPower/Condor are reasonable 723 based regulators (same as your Elpac if its a linear), the electrolytic capacitors are degraded due to age and should be replaced with something like Panasonic FMs. If you think his stuffing them into a chassis and installing the requisite knick knacks is worth the $175, fine, but don't expect better performance than your present Elpac.
You can still get the InternationalPower equivalent of those open frame linears from http://www.alltronics.com/cgi-bin/category.cgi?&category=41&start=43 , for $10, but I don't see the point if you've already the Elpac.
WRT medical linears, they don't offer significantly different performance than non medical versions. Medical versions simply have limited (by standards) leakage to ground. Unless you're going to operate your DAC in a hospital, I don't see the benefit.

lcrim · « **Reply #2 on:** 20 May 2006, 08:15 pm »

The Elpac PS that I bought from Allied is Mfrs p/n WM075-1950-D5, Allied Stk#879-0900 @ https://www.alliedelec.com/Search/SearchResults.asp?SearchQuery=WM075-1950-D5&Submit.x=24&Submit.y=4
I didn't specify the barrel connector so I received one w/ a DIN plug that had 4 wires and when tested one was +5.2 V DC, one was -5.2V DC one was the common and an additional ground wire. I think if you specify the barrel connector instead, it will be plug and play.
Please don't tell me its a switcher because it made a big improvement over the stock one.

edit: I'm including this because I got PM'ed about it.

Charles Calkins · « **Reply #3 on:** 20 May 2006, 08:51 pm »

Icrim:
I bought the WMO75-1950 with the barrel connector. Honestly I couldn't tell a difference in it sounding better than the stock switcher that came with the SB3. It worked okay for a week or so and then went completely bonkers. I went back to the switcher and since then everything is okay. I did finally read the fine print on it and it says to use with computer equipment only. Maybe they make one for use with gear like the SB3.

Cheers
Charlie

Occam · « **Reply #4 on:** 20 May 2006, 10:20 pm »

Quote

I didn't specify the barrel connector so I received one w/ a DIN plug that had 4 wires and when tested one was +5.2 V DC, one was -5.2V DC one was the common and an additional ground wire. I think if you specify the barrel connector instead, it will be plug and play.

Larry,

Its is indeed a single voltage (nominally +5vdc) linear supply. Your DIN 5 plug is configued as shown on the pdf you may download from the link you provided. The is no connection to the mains ground on that plug, but rather, a 'common'. The reason you measured -5.2vdc as opposed to +5.2vdc on one of your measurements is that you measured with the wires reversed. You'll see this from the DIN 5 configuration.

Charles - Excellent! This will allow you to save $$ on upgrades.

pm314 · « **Reply #5 on:** 21 May 2006, 01:41 am »

Quote from: Charles Calkins

Icrim:
I bought the WMO75-1950 with the barrel connector. Honestly I couldn't tell a difference in it sounding better than the stock switcher that came with the SB3. It worked okay for a week or so and then went completely bonkers. I went back to the switcher and since then everything is okay. I did finally read the fine print on it and it says to use with computer equipment only. Maybe they make one for use with gear like the SB3.

Cheers
Charlie

Interesting.....I've been using that same ps for a few months now without any problems. I think it sounds better but was not blown away by it.

Nick B · « **Reply #6 on:** 21 May 2006, 02:13 am »

Charlie It's quite interesting that you can get such good performance from the stock ps. Mine made the sound very harsh and luckily I stumbled onto the Aberdeen. Maybe some day I'll study electronics and attempt some DIY Regards Nick

Wayne1 · « **Reply #7 on:** 2 Jun 2006, 05:55 pm »

I was a bit curious about why Charles had a problem with his Elpac PS. I had recently listened to one and found it quite good.
Listening session at TweekGeek's

I got in contact with Charles and arranged to purchase his Elpac from him.

I received it yesterday. I opened it up today and did a few measurments. With no load, it was measuring 5.2 volts DC. I moved it around on my bench and the DC voltage dropped to 4.5. The SqueezeBox does not like DC below 4.85. I poked around the circuit board a bit and found a hairline crack in the trace going from the diodes to the filter cap. I jumpered the trace and all was well.

While I had the unit apart, I took a little time and replaced some parts. I changed the diodes to HexFreds and the filter cap to a higher value Panasonic, Low ESR, FC series. The resevoir cap was changed to an Os-Con cap I had on hand.

I compared the stock Elpac to the modded one in my HT system. I am running a modded SB2 digital out to a modded Panasonic SA-XR70

There was quite an improvement as I switched between the stock Elpac and the modded one. The modded one had improved dynamics, better high end and tighter bass.

All in all, a very nice change. If you can find the Elpac PS, I do think they are very nice and well worth the money.

JDUBS · « **Reply #8 on:** 8 Jun 2006, 02:24 am »

Quote from: Wayne1

I was a bit curious about why Charles had a problem with his Elpac PS. I had recently listened to one and found it quite good.
Listening session at TweekGeek's

I got in contact with Charles and arranged to purchase his Elpac from him.

I received it yesterday. I opened it up today and did a few measurments. With no load, it was measuring 5.2 volts DC. I moved it around on my bench and the DC voltage dropped to 4.5. The Squee ...

Wayne

Excellent info! Quick question, how did you go about getting underneath the Elpac's board? It's closely attached to the transformer which seems like it might be glued down.

Thanks!
Jim

Charles Calkins · « **Reply #9 on:** 8 Jun 2006, 02:38 am »

Yes I had problems with the Elpac power supply. Wayne seems to have found a defect in it and has rebuilt it to his satisfaction.
However I still say that when the Elpac was up and running in my system I couldn't hear a difference. Even before it went bonkers.
I'm very sure that an upgraded power supply for the SB3 helps. Everybody seems to think so. Far being for me to question the experts.
But I'll be darned if I'm going to spend $600 or $900 or $1200 on a power supply. Now if somebody says they have one that's the cats meow for say $100 to $200 now they have my attention!!

Cheers
Charlie

mgalusha · « **Reply #10 on:** 8 Jun 2006, 02:58 am »

Quote from: Charles Calkins

Now if somebody says they have one that's the cats meow for say $100 to $200 now they have my attention!!

You may get your wish Charles.

Wayne dropped by this evening with your rebuilt Elpac and a stock Elpac. Apparently yours had a cracked circuit trace so when he was repairing it a few modifications were done just to see if they would be cost effective. In my system there was a noticable improvement with the tweeked Elpac vs the stock one. He's thinking about offering mods to that PS for a very reasonable price, I don't know what price he'll end up at but what he was indicating would be closer to the low end of what you listed above and that was the PS plus the mods.

The sound wasn't as good as the mega buck PS but given the cost it was very nice IMO.

Mike

Wayne1 · « **Reply #11 on:** 8 Jun 2006, 01:36 pm »

Quote from: JDUBS

Wayne

Excellent info! Quick question, how did you go about getting underneath the Elpac's board? It's closely attached to the transformer which seems like it might be glued down.

Thanks!
Jim

The transformer is held in place with some VERY sticky double-sided tape. You have to be very careful and have the right tools to be able to remove the transformer without damaging the case. The leads from the transformer are attatched to the board with a very large amount of solder. You will need a solder sucker or vacuum powered de-soldering station to remove all the solder so you can work on the board. The traces on the board are very thin. Too much heat will cause the trace to come off the board.

I started on this "project" because I was impressed with the sound of the stock Elpac. I wanted to hear what it would sound like with mods. I was also curious as to why Charles didn't hear a difference between the SB switcher and Elpac. I bought the Elpac from him to satisify both goals.

I did not listen to Charles' Elpac first. I measured low voltage and repaired that first. Then I proceeded to replace parts. I think the changes are very noticable and all for the better. One AC member is sending me his Elpac to mod already. Hopefully he will post on the differences he hears when he gets it back.

The owner of the stock Elpac should be returning from vacation shortly. I will loan him the modded one to compare it to his stock one through his modded SB3 to a modded DAC 60. If both folks are pleased with the differences, I will offer a mod service for the Elpac PS. It will be between $75.00-$100.00 for the mods. I do not have any of the Elpac PS.

I will go into this a bit more in the BOLDER Circle.

Charles Calkins · « **Reply #12 on:** 8 Jun 2006, 03:39 pm »

After reading what Mike and Wayne had to say about my Elpac power supply I'm kind of thinking that it was on the borderline of not working when I had it hooked up to the SB3. Perhaps that is why I could never hear a difference.
So I think I'll get another Elpac and ship it to Wayne for mods. Who knows maybe this new one will have the same problem as the other. I'll let Wayne take care of it before I hook it up here.

Cheers
Charlie

lcrim · « **Reply #13 on:** 15 Jun 2006, 02:50 pm »

I sent my Elpac ps to Wayne on Monday for mods and received it back at work today. Very fast turnaround, thanks Wayne.
The SB3 that this powers is otherwise stock and has a coax out to a SN Chibi Dac. So I have something to look forward to when I get home tonight.

Wayne1 · « **Reply #14 on:** 15 Jun 2006, 03:29 pm »

Let us know what you think of the changes, Larry.

The gentleman who lent me the ELPAC in the first place came back from vacation last Friday. I gave him his modded SB3, stock Elpac and lent him the modded Elpac. He was back down here a few days later wanting his ELPAC modded

He should be picking it up tomorrow.

He is running a modded SB3 (with Silver Slipstream Bybee in the digital line) digital out to a modded DAC 60.

There is more information on the ELPAC mods here

lcrim · « **Reply #15 on:** 16 Jun 2006, 06:50 pm »

Follow Up-
Plugged in the modded Elpac PS- After listening late into the night, overall, my initial impression is that there is a huge reduction in harshness, one of those things that you don't realize until you hear the improvement. A very,very cost effective improvement.
The system where this SB3 works has been purposely pushed towards a big, warm tone. The preamp is a AE-3 which has NOS 6SN7GT-B's and the Decware Select amp has a ridiculously pricey 7308/E188CC as a signal tube all of which help slant the sound towards a very textured feel. The Elpac mods work to reduce grain or hardness further while reducing smearing. The gain knob on the preamp dropped w/o a loss of detail or dynamics. A very nice addition, I think.

Tweaker · « **Reply #16 on:** 16 Jun 2006, 08:14 pm »

Quote

There is more information on the ELPAC mods here

The link sent me to J&R Music World

Wayne1 · « **Reply #17 on:** 16 Jun 2006, 08:45 pm »

Sorry

That link was from another post on another topic.

I have fixed that link.

Here is another one.

Charles Calkins · « **Reply #18 on:** 27 Jun 2006, 12:18 am »

Hi Guys:
  I bought a new Elpac power supply because Wayne found a booboo in my old one. I sold it to Wayne and after he looked at it he found the problem and fixed it.
I've had the new Elpac P.S. up and running for almost two weeks. Works fine. No problems.
Today I went back to the stock P.S. because I'm sending the Elpac to Wayne for mods.
However even though I know this Elpac P.S. has no booboo's I still can't hear a significant difference in playback versus the stock P.S. I guess I should be. Everybody seems to think it's a big improvement over the stock P.S. I don't think I got ear problems. Maybe I do and Don't know. I wonder if the quality of the power coming into my house has something to do with it. The meters on my Belkin PF 40's read 124.5 right now. They never go below 122 or so. Does that seem high compared to what others have?
Goofy isn't it!!!

   Cheers
   Charlie