Chinese PSU voltage range

[brian2957]

As a few people have asked me this question I thought it best to start a new thread . I bought one of these http://www.ebay.co.uk/itm/25VA-24V-Hifi-linear-power-supply-amp-DAC-external-PSU-with-display-/111591718795?pt=LH_DefaultDomain_3&hash=item19fb627f8b from Grant ( struth ) a couple of weeks ago and have been using it ever since with my Amptastic Mini-1 ( set at 13.5V ) . For some reason the seller doesn't point out in his Ebay listing that these PSUs can be adjusted. This morning I had a bit of a play and had the PSU adjusted down to 5V minimum and 24V maximum so these appear to be quite flexible . I've compared this PSU to the PSU supplied with the Mini-1 and it does make for an audible upgrade in SQ .

http://i172.photobucket.com/albums/w2/brian2957/P1010482_zps6sizfnlg.jpg (http://s172.photobucket.com/user/brian2957/media/P1010482_zps6sizfnlg.jpg.html)

The adjustment can be made via the little brass screw to the rear of the transformer . Sorry but I'm not an electronics engineer ( nor a photographer for that matter :rolleyes: )so I don't know what these parts are called .
I also found that changing the cable and the plug on the DC cable was a worthwhile exercise . http://www.ebay.co.uk/itm/OYAIDE-DC-2-1G-AUDIOPHILE-GRADE-DC-POWER-PLUG-FITS-ARCAM-R-DAC-/150868469857?pt=LH_DefaultDomain_3&hash=item2320762861 Not cheap but excellent qualiity .
Tools required are a Philips screwdriver , an Allen key , and a little flat headed screwdriver . All available from the £1 shop . :D

[Firebottle]

Good one Brian. The part is a multi-turn pot (potentiometer).

:) Alan

[struth]

what do you mean you dont know what its called Brian...its a thingie :eyebrows:

[brian2957]

Thanks Alan . I thought it was called a Dooverlackie ( adjustable ) or summat Grant :D

[struth]

Thanks Alan . I thought it was called a Dooverlackie ( adjustable ) or summat Grant :D

:D

[maxrob200]

Thingameebob.

I ordered one of these so it's good to know that the voltage is adjustable. Does it come up on the display or does the voltage need to be measured using a multi meter

[brian2957]

It comes up on the display .

[agk]

Might be quite a handy box if the ampage was higher.

[Wakefield Turntables]

OK, forgive the really stupid question. Could one of these be used to power a turntable? I'm thinking my 301 which needs ~17W. :scratch:

[brian2957]

Works very well with the Mini-1 Andrew .

[brian2957]

OK, forgive the really stupid question. Could one of these be used to power a turntable? I'm thinking my 301 which needs ~17W. :scratch:

Sorry , I don't know mate . One for the experts on here .

[awkwardbydesign]

Bear in mind that with these regulators, the further the output voltage is from the DC voltage into them, the hotter they will get. The voltage you lose has to go somewhere, and heat is the usual place. So you will have less current available at lower voltages, as I understand it.

[agk]

Works very well with the Mini-1 Andrew .

I don't doubt it but at the right ampage (4/5 rather than the 1 of that supply) it'd probably be a killer listen.

[337alant]

The Linear technology make some very high quality positive voltage regulators in the LT1083-1086 series with amperage up to 7.5 amps dependent on In/out voltage but these are far superior to your standard LM317 regs
http://cds.linear.com/docs/en/datasheet/108345fg.pdf
Alan

[awkwardbydesign]

The Linear technology make some very high quality positive voltage regulators in the LT1083-1086 series with amperage up to 7.5 amps dependent on In/out voltage but these are far superior to your standard LM317 regs
http://cds.linear.com/docs/en/datasheet/108345fg.pdf
Alan

It does seem that the usual current limits apply, but a 7.5A regulator will come in very handy for me. I would pick my transformer to suit.
"Like any of the IC power regulators, the LT1083 has safe
area protection. The safe area protection decreases the
current limit as input-to-output voltage increases and
keeps the power transistor inside a safe operating region
for all values of input-to-output voltage. The LT1083
protection is designed to provide some output current
at all values of input-to-output voltage up to the device
breakdown."

[Ali Tait]

This one looks a bit more useful-

http://www.ebay.co.uk/itm/111583509613?redirect=mobile

[Firebottle]

That looks more the biz, the case is even earthed.

Plus the regulator pass transistors are actually mounted onto the big side heat sinks. If you look at the cheaper £125 model that comes up underneath the listing, the single transistor is mounted on a very small heatsink :mental:

:) alan

[brian2957]

That's the same seller for the two I have . This one is much dearer though .

[Firebottle]

Yes but it offers 5 times the output power ;)

[Ali Tait]

Might get one to power the phono stage..

[brian2957]

This is the one I'll be using with the Amptastic when it's returned from loan duty http://www.ebay.co.uk/itm/30W-DC12V-HiFi-Linear-power-supply-Regulated-PSU-for-DAC-headphone-amp-CL-215-/111544612626?pt=LH_DefaultDomain_3&hash=item19f893b712

[luvpies]

Hi which of the PSU's from this seller would be perfect for my Caiman II with V6 upgrade

Thanks
John

[brian2957]

Both will do the job , however I prefer this one which is a bit more expensive http://www.ebay.co.uk/itm/30W-DC12V-HiFi-Linear-power-supply-Regulated-PSU-for-DAC-headphone-amp-CL-215-/111544612626?pt=LH_DefaultDomain_3&hash=item19f893b712&clk_rvr_id=846270913050&afsrc=1&rmvSB=true
Both will adjust to the required voltage and come in similar cases .
Just to take things a little further these PSUs respond very positively to upgrades to the DC cable ( ie better cable and DC plug http://www.ebay.co.uk/itm/OYAIDE-DC-2-1G-AUDIOPHILE-GRADE-DC-POWER-PLUG-FITS-ARCAM-R-DAC-/150868469857?pt=LH_DefaultDomain_3&hash=item2320762861 ). Not cheap , but a worthwhile upgrade .

[luvpies]

Both will do the job , however I prefer this one which is a bit more expensive http://www.ebay.co.uk/itm/30W-DC12V-HiFi-Linear-power-supply-Regulated-PSU-for-DAC-headphone-amp-CL-215-/111544612626?pt=LH_DefaultDomain_3&hash=item19f893b712&clk_rvr_id=846270913050&afsrc=1&rmvSB=true
Both will adjust to the required voltage and come in similar cases .
Just to take things a little further these PSUs respond very positively to upgrades to the DC cable ( ie better cable and DC plug http://www.ebay.co.uk/itm/OYAIDE-DC-2-1G-AUDIOPHILE-GRADE-DC-POWER-PLUG-FITS-ARCAM-R-DAC-/150868469857?pt=LH_DefaultDomain_3&hash=item2320762861 ). Not cheap , but a worthwhile upgrade .

Thanks Brian nice one

[337alant]

You could build your own as well of course
Below is a one I built for my Young dac power supply it has an adjustable output voltage and 1.5A
Old Dac case used, Encapsulated transformer, Qspeed fast rectifiers with tripple low ERS muse cap wit Inductor / resister filtering between caps for better ripple smoothing and the Voltage regulator is an avondale TPR2 (Tracking Pre Regulator) it made a massive improvement to the young dac and is a nice quiet 18V DC supply

https://c1.staticflickr.com/9/8517/8556711131_74956611bd_c.jpg (https://flic.kr/p/e38o7g)Young Dac power supply (https://flic.kr/p/e38o7g) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

https://c1.staticflickr.com/9/8228/8556716031_1fda6e8f04_c.jpg (https://flic.kr/p/e38pyK)Young Dac power supply 2 (https://flic.kr/p/e38pyK) by Alan Towell (https://www.flickr.com/photos/69508926@N05/), on Flickr

Alan

[luvpies]

Nice Alan, but I haven't got a clue and have never used a soldering iron dude, wish I had the skills

[Beobloke]

OK, forgive the really stupid question. Could one of these be used to power a turntable? I'm thinking my 301 which needs ~17W. :scratch:

Doesn't look like anyone ever responded to this for you, but the answer is no. The 301 uses an AC synchronous motor that requires 115 or 230Vac input - the PSU being discussed here outputs 24Vdc.

[Desmo]

There's also a 5v version of this unit which is perfect for those of you with Raspberry Pi based DACs. You need to modify the cable to suit, but it's a very easy job, with just 2 wires to solder.

[drpetar]

Yup, I already took one of these 5v/2.5a PSUs (http://www.ebay.co.uk/itm/111312388829?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT) , though didn't make any soldering, just bought one of these adapters (http://www.ebay.co.uk/itm/371327538387?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT).

BTW the PSU shows most of the time 5.20 V, is that normal?

[Desmo]

Thanks for the link, but I did not want to put an additional connector into the chain, so I got hold of a nice high quality USB cable that I used as the basis for my custom lead.

I have three of these PSUs and have checked the display voltages on each of them with my multimeter, on the whole, the display on the units is a little higher than the readings on my multimeter. For the Pi, I have set the voltage by multimeter to exactly 5.0v, and the display on the unit reads 5.04v so pretty close. If you are worried, then it's easy to adjust the PSU by turning the brass screw on the trim pot inside the unit.

[drpetar]

Great, thanks for the info. :thumbsup: I haven't opened the PSU so far and was wondering if it is adjustable as the Brian's one.