Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion HiFi & HT Chat The Philosophy of Tweaking Equipment

Wow Bryon you're a mad man! How does it sound?

It sounds excellent. Improvements include... greater resolution, greater dynamic range, lower noise floor, more natural harmonics, more precise imaging.

I can't say I regret any of the mods. I know there is a school of thought that mods are sacrilegious, and that the manufacturer knows best. I don't doubt for a second that Meridian knows more than I do, but I am also aware of the fact that every design is a compromise between performance and price. In many cases, that results in the use of suboptimal parts. Exhibit A is Meridian's choice of power supplies, which are chosen for price rather than performance, IMO.

I know some folks believe that modding results in sound that is different, not better. I don't doubt that, in some cases, they are right. But the collective results of my adventures in modding has left me with the belief that it is the most cost effective way to improve a system.

Bryon

It would seem that the just released 808 tells you that there is a case for modding. From what I can read, it looks like they have changed the power supply for a toroidal power supply. Why not the 861 or the G series?

"818 Reference Audio Core features a power supply design built around a true toroidal transformer for minimum noise and maximum signal integrity."

The removal of all the video cards makes great sense, being as no one really uses them with the HD621. I wonder if you pulled out all the video cards and pushed all the cards you need to one side in the 861, if there is rooms for this new Meridian "true toroidal transformer".

I removed a total of 5 cards from my G68ADV. The results were eye opening -- a BIG improvement in sound quality. I suspect the improvement was attributable to three things: interference, current draw, and heat. With the unused cards removed, there is less of all three.

I was having problems with my G68 at the time, so I don't know if the improvement I experienced is generalizable to other G68's or other Meridian products, but I suspect that it is.

It is an absolutely trivial modification, and completely reversible. Just store the unused cards in a very safe place.

Bryon

It's almost worth doing to reduce the quiescent power usage in standby... As you say, no-one uses the G68ADV for video.

This does help prove Meridian's point regarding not having HDMI inside the processors for sound quality reasons.

Steve.

VK and Steve - I agree with both of you.

The problem of heat buildup is worth expanding upon. In many ways, the modular design of the G68 is brilliantly elegant. But IMO, the single biggest design flaw is inadequate ventilation, which is a consequence of...

1. Its largely sealed exterior.
2. The fact that the PCB's are stacked horizontally.
3. The vertical proximity of the PCB's.
4. The placement of the fan.
5. The absence of feet.
6. The number of PCB's (in the ADV in particular).
7. The recent choice of power supply (XP Power).

Some of these decisions were probably cosmetic (the largely seal exterior, the absence of feet, the vertical proximity of the PCB's to lower the unit's overall height), some ergonomic (horizontal placement of PCB's = intuitive RCA's on rear panel), some market driven (more PCB's = more functionality) some budgetary (the power supply), and some unavoidable consequences of other design characteristics (the placement of the fan). Collectively, these design choices result in a toaster. As everyone knows, that's bad for sound and reliability.

It's worth noting that the new G68 power supply from XP Power runs much hotter than the earlier G68 power supply from Universal Microelectronics, which failed in so many units (including mine). Like the UM PSU, the XP PSU is a switching mode power supply, so it should run relatively cool. Unfortunately, it does not. :-(

Most of the items on the list above can be changed through modification, if someone is so inclined. I can say that, after addressing most of the items above, my G68 is cold to the touch even after hours of operation, and it is much happier because of it.

Bryon

Your modifications seem extensive, thorough and impressive. It makes me wonder why you bought a Meridian platform to modify. As your changes were so extensive could you not have started out with something cheaper and achieved a similar result?

That's a fair question. The answer is that I never planned to mod the unit when I bought it. Then the power supply died. Meridian's replacement power supply sounded significantly worse, IMO. So I hired a modder to create a custom power supply. That was my first step onto the slippery slope. Soon I was asking him to replace the clock, the op amps, etc...

After I got the unit back from the modder, it developed a freezing problem, which was being caused by heat buildup. So I did some mods of my own to minimize heat. I discovered that the more circuits I removed from the unit, the better it sounded. So I wound up removing 5 cards, disconnecting the power button, and cutting out the blue LED's.

At the end of it all, I have what may be the most modded G68 in existence.

Bryon

Bravo!

I guess this was why I bought a G61, though, it never had the "extras" I new I would never use anyway.

I wonder if these mods are more noticeable in an analogue setup though. For people with DSP's, is it such a clear cut improvement. Anyone with any experience ?

I guess the G61 is less of a modders paradise, because of the smaller space.

Cheers
Greg

Some of the mods I've done are relevant only to the analog output, e.g., op amps, analog output buffer, analog output capacitors.

Others mods I've done could potentially help the digital output, e.g., better clock, better power supply, better RCA connectors, removal of unused circuitry to reduce heat and interference. To varying degrees, these mods can be effective at reducing noise and jitter.

Having said that, I don't know much about Meridian's DSP speakers, other than they sound wonderful. In particular, I don't know how they handle jitter. If DSP speakers reclock the digital data stream, and if the reclocking is done with a very high precision clock, then many of the mods above might be superfluous to a Meridian digital setup.

Of course, the DSPs themselves could always be modded... :-)

Bryon