DIY power supply for squeeze box

crooner · « **Reply #20 on:** 10 Apr 2007, 03:35 pm »

That's a nice looking PS!
I thought about using a single large cap like your 63V Cerafine. However, I happened to have a couple of smaller Cerafines in my parts bin so I used those in parallel. The advantage of using smaller caps in parallel , specially low ESR types, is a much "faster" power supply. A technique frequently seen in power amplifier circuits by Bryston and Creek.

I am about to embark in the MKIII project Power Supply. I will be using a medical grade Condor open frame unit rated at 12 amps. It should occupy the whole space of my black anodized box. Since this supply has a huge filter cap, I plan to replace it with several smaller caps in parallel plus a better quality bypass than the one I'm using right now.

I will also replace the DIN connectors for the DC cable with top quality XLR Neutrix.

I hope the larger supply doesn't hum too much and runs cool.

Stay tuned for pics when I start working on it!

Quote from: F-100 on 10 Apr 2007, 02:37 pm

Hi Crooner,
Here are some pics of Tanchiro58 and my DIY power supply. With all the upgrades, this power supply is rock solid.

This pic was taken before I added the bypass cap across the big Elna Cerafine 10,000uF/63v and replaced the two diodes with Hex Fred.

F-100 · « **Reply #21 on:** 10 Apr 2007, 05:07 pm »

Thanks Crooner and I'm looking forward to learn more about your MKIII project Power Supply.
Please keep us posted on your progress.

F-100 · « **Reply #22 on:** 10 Apr 2007, 05:09 pm »

Quote from: JoshK on 10 Apr 2007, 03:12 pm

I have a 1u chassis that I'd like to transplant the SB into so that I can have room to try such things.

JoshK,
Do you have any pic of this 1 chassis?? Thaniks

JoshK · « **Reply #23 on:** 10 Apr 2007, 05:47 pm »

I haven't taken a picture of it yet. I bought it from Bill @ Response Audio when he was selling off some extra chassis's. It is all aluminum, silver... I can take a picture if you like.

F-100 · « **Reply #24 on:** 10 Apr 2007, 06:17 pm »

I think I saw a pic of that chassis before ....
I'm also in the hunt for a bigger chassis to house the SB3 too but still haven't found one that I like yet.

JoshK · « **Reply #25 on:** 10 Apr 2007, 06:25 pm »

What style are you looking for?

F-100 · « **Reply #26 on:** 10 Apr 2007, 07:48 pm »

Not sure yet!! Something that look artistic and exotic. aa

crooner · « **Reply #27 on:** 10 Apr 2007, 08:11 pm »

Quote from: F-100 on 10 Apr 2007, 06:17 pm

I think I saw a pic of that chassis before ....
I'm also in the hunt for a bigger chassis to house the SB3 too but still haven't found one that I like yet.

The SB3's form factor doesn't lend itself to an audio style chassis.

I also have plans for a custom case. I have just acquired a SB2 for this purpose. Technically it is functionally identical to the SB3 with a big difference: the display is on a separate PCB, attached to the motherboard via ribbon cable. This makes installation on a custom case quite easy.

tanchiro58 · « **Reply #28 on:** 12 Apr 2007, 12:03 am »

Quote from: JoshK on 10 Apr 2007, 03:14 pm

At this point, I don't know if it is worthwhile, but if there is min orders or other impedances to ordering the tx's, do any of you guys want to get together for a mini-groupbuy on these transformers. I am willing to pick one up to test out.

Hi JoshK,

I would like to try for the best sound. Please count me in. Thanks.

Regards,
Tan

JoshK · « **Reply #29 on:** 12 Apr 2007, 01:49 am »

ok, so there are two of us...anyone else down/

2wo · « **Reply #30 on:** 12 Apr 2007, 03:31 am »

Yea, I'm game...John

rotcoddam · « **Reply #31 on:** 12 Apr 2007, 04:02 am »

Josh,
Count me in for one. Marty

Builder Brad · « **Reply #32 on:** 12 Apr 2007, 09:59 am »

Hi Crooner + F-100

nice power supply builds.

I also have one of those 3 amp Power One modules, although I managed to melt the transformer when I mis read-the connection info and left one of the wrong links in place. I will still use the Power One pcb and now intend to add a different EI core transformer - the thing is I dont know the AC output voltages on the pins marked A-AT-A - I could guess at around 4-0-4, but as you both have working units, would you mind measuring those voltages please?

Brad

Builder Brad · « **Reply #33 on:** 12 Apr 2007, 10:00 am »

Hi Josh,

I would alos be interested in a couple of those 1:1 digital isolation transformers, although hopefully postage to the UK will not cause any problems.

Builder Brad · « **Reply #34 on:** 12 Apr 2007, 10:04 am »

Josh,

count me in - postage should not be a problem.

Brad

tanchiro58 · « **Reply #35 on:** 12 Apr 2007, 11:44 am »

Quote from: Builder Brad on 12 Apr 2007, 10:04 am

Josh,

count me in - postage should not be a problem.

Brad

Brad,

Search for www.scientificonversion.com or email kathyparker@scientificonversion.com to order the SC974-02 lead free since you are located in UK (we use a lead one). There is no different sonically and physically but the price. I bought one that costs USD16.00 for a Non Lead Free. You will be very happy with your SB3 after completing this mod. Good luck.

tanchiro58 · « **Reply #36 on:** 12 Apr 2007, 11:57 am »

Quote from: Builder Brad on 12 Apr 2007, 09:59 am

Hi Crooner + F-100

nice power supply builds.

I also have one of those 3 amp Power One modules, although I managed to melt the transformer when I mis read-the connection info and left one of the wrong links in place. I will still use the Power One pcb and now intend to add a different EI core transformer - the thing is I dont know the AC output voltages on the pins marked A-AT-A - I could guess at around 4-0-4, but as you both have working units, would you mind measuring those voltages please?

Brad

A-AT-A have an equal voltage of 9 Volts. Each A connects to each diode and AT to the positive of the main PS capacitor (as you see in F100 pics the Elna Cerafine one). Any question please feel free to ask me. For the EI tranny replace is it not worth for you, just get another new PS-One (ask F100 for info) . Good luck.

Cheers,
Tan

Builder Brad · « **Reply #37 on:** 12 Apr 2007, 12:27 pm »

Hi Tan,

thank-you.

do you mean 9v AC between A-A, with AT measuring 4.5v from either A pin?

I am not worried about the lead free option as I still have plenty of leaded solder

the Power One PS cost £30 so its worth me replacing the transformer, which I can do for less than £10, unless you know of a source of lower cost Power one modules? should I talk to F100 about this?

Brad

tanchiro58 · « **Reply #38 on:** 12 Apr 2007, 12:47 pm »

Quote from: Builder Brad on 12 Apr 2007, 12:27 pm

Hi Tan,

thank-you.

do you mean 9v AC between A-A, with AT measuring 4.5v from either A pin?

I am not worried about the lead free option as I still have plenty of leaded solder

the Power One PS cost £30 so its worth me replacing the transformer, which I can do for less than £10, unless you know of a source of lower cost Power one modules? should I talk to F100 about this?

Brad

Brad,

When I replaced the wires (for the best performance I use pure copper silver plated wire) in the PS-One I measure each A-AT was 9VAC not 4.5V. I did not measure A-A. For the tranny of PS-One Hammond tranny is a good candidate unless you get a toroidal one which I know is the most low noise and expensive one.

Tan.

JoshK · « **Reply #39 on:** 12 Apr 2007, 01:32 pm »

Tan, toroids have a lower magnet field generation (not quite the right terminology) but they are not what I call 'low noise' meaning they pass all the noise that is on the line much more readily than a comparable EI. This is because they are wideband, which really isn't a benefit in power supply noise.

Plitron makes what they call a low noise toriod and in essense it is a narrower band toroid. Toroids also typically have more interwinding capacitance between the primary and secondary, so filtered crap gets back into the supply more readily as well. I have Occam to thank for my brief education in transformers.