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I just want to warn you against Mauimods /Aberdeen Components(actualy the same company)
I ordered and pre-payed a power supply upgrade for Meridian/tact processors.
I recived a faulty product, and returned it - since then it has been impossible to get a reply from the company, I have sent more than 30 emails over the last 3 months - and no reply.
Dennis,

Sorry to hear about your bad experience with Mauimods. Some people sing their praises, but others never get what they pay for.
Originally Posted by ncpl
Shame you didn't take notice of Brucemck2 at the start of this thread as he warned you similarly. Live and learn.
Nick,

Didn't you try the Aberdeen power supply some time ago? I've been trawling the old threads, but I didn't really see any conclusive comments from you?

This has jolted my interest in better power supplies, and if Mauimods aren't trustworthy, maybe there's a good linear PSU alternative. I found lots of information here:
https://www.meridianunplugged.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=41609&page=1
https://www.meridianunplugged.com/u...bb=showflat&Number=120545&page=1
http://www.audiocircle.com/index.php?topic=27713.0
http://uk.farnell.com/linear-technology/slt12-20404-12t/linear-power-supply-nw/dp/1690684
http://www.audiophonics.fr/amplificateurs-diy-alimentations-c-23_108.html
http://www.solahd.com/products/powersupplies/silverline.htm
http://uk.farnell.com/calex/32305b/psu-open-frame-5v-3a-12v-15v-1a/dp/4893890
http://www.Meridian-audio.info/public/technote_tn7a_-_800_series_psu_exchange1%5b3442%5d.pdf
http://www.calex.co.uk/downloads/datasheets/32000_h.pdf

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800 series PSU exchange: XP to UMEC
Old-type PSU: UMEC UPO653S-01
New-type PSU: XP ECM40UT31
Yellow (12V)
Red, Red (5V)
Black, Black (0V)
Blue (-12V)
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I believe the ps in the Meridian G68 is the UPO-653S-01 made by Universal Microelectronics -
http://www.umeu.de/
Its an open frame 3"x5"x1" 90-264VAC switcher producing
+ 5vdc @5A
+12vdc @2A
-12vdc @.5A
1%, 3% & 1% load regulation
50, 120, & 120mv p-p ripple respectively.
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For a alternative drop in solution, Use a Condor GLC-65A.
It is the best I found. Unless someone can suggest a better one.
It looks like all the G-series & 800-series units (and the HD621) run on +/-12V & +5V supplies, which are commonly available from many manufacturers. Switching supplies typically produce 100-200mV ripple and noise, while good linear supplies are down at 1-2mV. That's a 40dB improvement in power supply performance, and regulation is very good as well.

These are the improvements to the internal supplies, but I believe linear supplies cause much less RF emission down the power lines to other equipment. If I recall correctly, Martin Colloms measured 10dB more noise from the system when the 800 was switched on - and he thought that was good going. So even if a switching supply is adequately filtered internally, it probably degrades everything else that's hooked-up. One of the reasons why AV systems tend to sound worse than stereo systems IMHO.

So I think there's plenty of motivation for upgrading the PSU, not only in the player or controller, but potentially in the HD621 as well. This makes me wish I still had my G68D, so I could play with it, and compare with the 861V4. Linear supplies are inevitably bigger and hotter than switching supplies, but there's usually plenty of space in there. Just watch out for disreputable suppliers.

BR, Nick