Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems The new Clean Debate about Clean power supplies

I know it doesn't make sense to me either just because its an audio product. High end audio product! The cost factor is the only reason I can figure. As well as keeping the G series as a lower level product line under the 800 series. My experience is with ITE and telecom products so a cheap out sourced supply can cut cost.

Ron

I have really no experience with power supplies but this is an interesting debate none the less. How does the power supplies of the G-series line compare to the 800 series? What is used in the 800's?

Well Guys! Guess what?

The 568.2mm is linear! It has a transformer with multiple taps and separate regulation on every board.

Looks like someone else will have to try this tweak on a G68. I don't know where I read it had a switcher. I think the 598 has a switcher. I'll open that up next since I need to add my SDI output.

Oh well! I feel better knowing its a linear. Noise spectrum is unmeasureable. Ambient noise too high although not bad.

Ron

Ron,

Very interesting report.

I wonder why M changed to a switching supply in the G68?

Thanks

By the way...no line filter in the 568.2!

They have a ferrite bead with one turn around the AC line inputs. I'm adding some ferrites to the output taps of the transformer to help attenuate any noise going to the analog board. I'll add one to the digital section as well. Easy to do just a snap on bead. I'll add a couple extra beads to the AC lines as well. Can't hurt.

Finding out that the 568 has analog supply might tell the story why some think the G series is brighter sounding than the 568. Interesting thought.

Ron

My guess would be that Meridian decided to use a SMPS in the G Series to allow worldwide input voltage compatibility without different models for different markets.

I can't think of any better reason!

Ron

Ron,

When I open up my pre/pro's, one of the reasons I do it is to apply Pro Gold to any of the connectors I can undo internally.

May be worth doing if you have some and its still open.

Also interesting that there is no IEC/filter combo. My G68 doesnt have one anymore either - hahahaha!

BTW - My G68 had a ferrite ring (from the factory) immediately after the IEC/switch/filter combo. The line & neutral incoming power supply wires were wrapped one time through it. I moved it to the ground wire, as Anthony does.

Steve,

I didn't have any Pro Gold. It was easy to open up the 568.2.

With a line filter in the G68 the ferrite must be a leftover from the 500 series. Just never removed. These would most likely be in there for EMI reasons. Radiated emissions to pass approvals. A ground ferrite is good to attenuate noise on ground but your RCA's and XLR connections will all act like antennas and pick up external noise. My thought is to use them for common mode noise. Pass L/N/G through the ferrite. I added a few extra ferrites and one has all three lines through the ferrite. I float my safety ground any way. Sounds better in my system. The amplifiers are grounded. I only like to ground at one end. And even there I use AC grounding through a cap on every line. Thats what sounds the best in my system. I had yard work to do today so haven't auditioned the extra ferrites. Might not make much of a difference but I figured I had them so I might as well try it.

Ron

By the way they probably needed the line filter in the G68 because the switching supply is noisy and it wouldn't pass emissions requirements with out it. Just a thought.

Ron

System sounded a tad more laid back with the extra ferrites. What really sounded better is I removed my 598 from the same power tap on my AC regulation that my 568 was plugged into. Much more laid back soundstage now. Vocals even smoother with more depth and palpable soundstage. WOW! Could it be the 598 switching supply...or maybe the line filter in the 598 dumping supply noise to ground? Guess I still need to do more investigation. Does the 598 have a line filter? Will know soon I haven't opened it up yet. Its amazing how interaction between components on the AC power side came make so much of a difference sometimes.

Ron

While I was put off with the tone of Anthony's response, still I wonder if it would be fair for us to ask you for measurements confirming that adding the ferrite beads and changing the power tap for your 598 resulting in measurable changes which would account for the "much more laid back sound stage" you are hearing.

Please understand that this is not directed at you Ronomy; it is intended to be a thought provoking rhetorical question.