Inexpensive linear power supply for DUET and DACs

Wayne1 · « **on:** 9 Jun 2009, 09:11 pm »

Parts Express is offering a very good price on this variable power supply, part number 120-536

Under $20.00.

It can output 9 volts at 2 amps. Perfect for the DUET.

It can also output 12 volts @ 2 amps. This should work just fine with quite a few DAC's that use wallwarts.

I received one late last week. I took it apart today. It IS inexpensively built. I decided to see if maybe it could be made to sound a bit better. I replaced the filter, reservoir and bypass caps. I also upgraded the regulator used. It took a bit to fit everything back in the box, but it was worth it.

There was quite an improvement over the stock PE supply. The PS supply in stock form is quieter and supplies more dynamics then the stock wallwart that comes with the DUET.

It does not sound as good as one of my Standard supplies but it is VERY good for the price.

I am looking of someone who has a stock PE supply to compare it to the modded supply and post their thoughts.

Please PM or E-mail me if you are interested. If others think the mods are worth it, I will offer them on the website for about $100.00 without the PS. I can also build various cables to connect to a DUET or most DC plugs.

The PS does not output 5 volts in stock form. If anyone is interested in using this supply for 5 volt, I can mod it to do that. Just drop me a PM about it.

This mod will not be on the BOLDER Cable website, yet. Please contact me directly if you are interested.

Wayne1 · « **Reply #1 on:** 25 Jun 2009, 01:59 pm »

The modded PE supply is on it's way to a "beta tester" for evaluation. I built a DC cable for it and sent it out yesterday.

Hopefully, we will get some feedback on this little PS.

I think it is a great value and upgrade for any device that uses a switching wallwart.

I can modify the unit to output just about any voltage from 3.3 to 12 volts DC at 2 amps.

I can build DC cable to fit most connectors.

Wayne1 · « **Reply #2 on:** 7 Dec 2009, 06:05 pm »

I just noticed today that the power supply at Parts Express has been back ordered to February 20, 2010.

Parts Express Power Supply

MCM Electronics offers the same power supply but wants $28.00 for it.

MCM Power Supply

If you want a nice linear power supply to replace the factory wall wart for your Squeeze Box, DAC or other low voltage project, I can highly recommend this supply. I do offer mods for it Power Supply mods and I can change the voltage to 5 volts, if you wish to run a SB3.

For a review of the modded power supply please check out this thread.

nbndtrain · « **Reply #3 on:** 25 Jan 2010, 10:47 pm »

I ordered one from MCM since Parts Express moved their backorder date out. Measuring the DC output though, I am getting really high output on all settings. 9v is measuring at 18v. Any suggestions? My multimeter isn't great, but the stock Duet wall wart measures right at 9v. The 3v setting on the linear measures at 10v, is that safe to use?

Wayne1 · « **Reply #4 on:** 25 Jan 2010, 10:52 pm »

I would check your meter setting to make certain. I have measured quite a few of these supplies and they all were dead on the voltage.

It may be possible that the power supply was bounced around in shipping. The voltage selector switches between different resistors to set the voltage out of the regulator. Contact who you bought it from to see if they will replace it.

If not, send it to me and I'l take a look at it for you.

nbndtrain · « **Reply #5 on:** 26 Jan 2010, 01:01 am »

Thanks Wayne1 for the heads up on this power supply, and offering to look at it. I opened it up and the pcb is cracked, and it's definitely way out of wack. Will be calling MCM in the AM. Hopefully a painless exchange. I am in Denver, so hope to meet you some time.

nbndtrain · « **Reply #6 on:** 1 Feb 2010, 08:43 pm »

Received the replacement from MCM, and it measured out correctly. Sound is much fuller, better stereo seperation, and don't have to crank the treble anymore. Great, inexpensive upgrade, and definitely shows that power supply upgrades can yield a lot of performance gains.

Wayne1 · « **Reply #7 on:** 2 Feb 2010, 01:53 am »

Quote from: nbndtrain on 1 Feb 2010, 08:43 pm

...definitely shows that power supply upgrades can yield a lot of performance gains.

Just think about what your DUET would sound like with an even better power supply

pianoguy · « **Reply #8 on:** 13 Mar 2010, 02:07 am »

I am interested in this item and curious about its benefits. I was also wondering what the appropriate cable is to run from the binding posts on this power supply to the Duet (i.e. what is the exact size of the DC plug that I would need to order?)

The main problem for me is that I live in Canada. To get the power supply and cable sent here after conversion/taxes/shipping, it appears that it is going to raise the cost to $50-70 CAN, depending on the shipping method I choose. Unfortunately, it's not so economical anymore.

I don't suppose anyone is aware of a similar product is available in Canada?

srb · « **Reply #9 on:** 13 Mar 2010, 02:58 am »

Quote from: pianoguy on 13 Mar 2010, 02:07 am

I don't suppose anyone is aware of a similar product is available in Canada?

Newark has Canadian sales offices. You might want to give them a call and see if this product can be shipped from a Canadian location, or if ordering from the canada.newark.com website will eliminate additional fees.

http://canada.newark.com/mcm/mw122a/multi-voltage-regulated-power-supply/dp/51B412?Ntt=mw122a

Steve

eclein · « **Reply #10 on:** 5 May 2010, 04:37 pm »

I finally got around to ordering the power supply you suggested Wayne. Its due today, I just pick the right connector from the set and switch the PS to 9V correct?? I have a Duet and look forward to trying this power supply...If I don't blow it up I'll post about results if thats OK??
Ed L.

Wayne1 · « **Reply #11 on:** 5 May 2010, 04:42 pm »

Ed,

Make sure the polarity is correct. The center pin should be positive.

You should be able to hear an immediate difference. This will change a bit over the course of two weeks. If you want even better sound, send it to me for some mods.

Next level up would be one of the power supplies I make.

I have no problem with you posting your thoughts on the PS here.

mr_bill · « **Reply #12 on:** 5 May 2010, 05:33 pm »

Wayne,
I just purchased this same set - power supply and attachment connectors.
Regarding polarity - isn't there only one way to put the connector on the cord?
Thanks.

Wayne1 · « **Reply #13 on:** 5 May 2010, 05:38 pm »

Quote from: mr_bill on 5 May 2010, 05:33 pm

Wayne,
I just purchased this same set - power supply and attachment connectors.
Regarding polarity - isn't there only one way to put the connector on the cord?
Thanks.

I don't know. I have only used the transformer. I have built cables to use with the DUET. There are the positive and negative connectors on the front of the PS. Just make sure they are connected correctly. I always measure voltage at the connector just to make sure nothing is connected wrong.

eclein · « **Reply #14 on:** 5 May 2010, 05:52 pm »

Haha..it couldn't just be easy.
The plugs can go in either way to the end of the cord...I'm matching the + side of the plug with the receptacle side marked "tip"??
Does that sound correct?
Also the wire that connects to the PS itself has of course two wires one of which has a white line so I'm assuming thats the + one?
I think I'm right, its logical and Wayne you did say to make sure center pin was positive, thats considered "tip" isn't??
If you don't hear from me I blew up....

eclein · « **Reply #15 on:** 5 May 2010, 06:16 pm »

OK...I'm alive and well, nothing is getting hot so I think I hooked it up right...I'm shocked at how much better everything sounds.
Immediately noticed more detail and tighter low end...cymbals sound clean and metallic like they should, I love it THANKS Wayne!!!
If anyone is out there and hasn't done this simple tweak, go for it, best bang for my buck yet!!!

Wayne1 · « **Reply #16 on:** 5 May 2010, 07:12 pm »

Quote from: eclein on 5 May 2010, 06:16 pm

I'm shocked at how much better everything sounds.
Immediately noticed more detail and tighter low end...cymbals sound clean and metallic like they should, I love it THANKS Wayne!!!

Ed,

I'm really glad you hear the same thing I do with a linear PS vs the stock switcher. Make sure the stock PS is unplugged from the wall. The noise it makes can travel through your AC to pollute the rest of your stereo. The same thing happens with most switching PS. Keep your computers, cell phone chargers, etc as far away from your stereo as possible.

Nick77 · « **Reply #17 on:** 5 May 2010, 08:30 pm »

Quote from: eclein on 5 May 2010, 06:16 pm

OK...I'm alive and well, nothing is getting hot so I think I hooked it up right...I'm shocked at how much better everything sounds.
Immediately noticed more detail and tighter low end...cymbals sound clean and metallic like they should, I love it THANKS Wayne!!!
If anyone is out there and hasn't done this simple tweak, go for it, best bang for my buck yet!!!

When your ready to really kit it up another notch, send that puppy to Wayne.

mr_bill · « **Reply #18 on:** 5 May 2010, 08:42 pm »

Can this power supply also be used with the new Touch or is the new switching power supply better than the PE supply?

Wayne1 · « **Reply #19 on:** 5 May 2010, 08:56 pm »

The Touch requires 5 volts and 3 amps, at least, if it is going to be used with a USB hard drive.

While the PE PS can be modded to output 5 volts, it will be running really hot driving even just the Touch.

The stock switcher is not any better with the Touch compared to the one with the SB3. It just has a ferrite collar on it to reduce some of the noise. It is still really harsh, in comparison to a good linear.