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

I'll start.

For any mod or change that claims improved bass.

Use MRC plots before and after to see if you can show the difference.

I suggest 3 Clean Runs before and after the change and record plots of at least 2 speakers.

Be sure everything else is stable, speaker positions, cushions on the couch etc. everything.

George, one problem I can see is that when I run several MRC's back-to-back, with as near to identical positions as can be had, I don't get consistent decay times anyway. Not sure if you find the same thing happening. They can vary by 10+ms between runs.

Therefore, with this degree of variability, it might be impossible to measure effects that might be orders of magnitude smaller.

It is not unlike the "snake-oil cables" thread I ran a few months back. My ears could hear a difference in performance into the 8k's but I'd be amazed if it was something that could be measured via an spl meter. The changes were just too subtle and not really related to levels. More about textures in sounds etc.

Ironically, you may recall that I tried to stay well clear of the Punch and Judy name calling about cables to avoid what sadly occured in the original thread here.

However, in the same vein as that thread, I'd like to know if the PSU changes do yield +ve changes in G68/568's, particularly in DSP setups, and why that is.

Ronomy, I hope you can pursue this to some extent. Do keep us posted.

cheers

Nick,

I'll try repeated runs and see what I get.
I should rerun it anyway.

I too am interested in any experiments Ron does, I highly respect his opinion, even though I might not agree 100%. But that's ok.

George

George,

MRC isn't the only way to tighten bass response. Bass tightness varies with every recording yet the decay times don't change in the room. I can lower my sub by 1dB on a track and get tighter bass. Cleaner bass lines will sound tighter. Extra high end frequency extension can make the bass sound tighter and less bloated. Almost the same as lowering the sub. Yet the room doesn't change. The long decay time people are measuring are there rooms. Unless your in an anechoic chamber your not going to measure any major differences. There are other factors...The tighter bass is most likely from less distorted bass or cleaner top end making the bass sound tighter. Also better dynamics do to cleaner power will make bass sound tighter. The plots will look the same.

Hell the other day I lifted my speaker cables off the carpet and WOW! More air in the soundstage yet bass sounded thin. Image sounded flatter. I was reading a Mapleshades flyer and I had read this before that setting your cables on the carpet is bad because of the added storage capacitance by the cheap dielectric in the carpet. It smears the imaging because this capacitance interfers with the EM field around the cable. I'm not sure I really liked them lifted off the carpet. I put them back down and it immediately sounded back to the way it was before I lifted them. My cables have very thin teflon insulation on them so while on the carpet the copper is very close to the carpet. I've tried this before with other garden hose like cables and didn't hear a difference. But they had thick outer insulation on them. I still need to check again to make sure my ears were not tricking me. I tend to go back and forth till I'm sure it isn't just me or the air pressure due to low pressure/high pressure weather fronts moving through or my mood at the time. So many factors can fool our ears. Like you know the weather has been up and down here in Mass the past few days.

It still was a big difference...it really surprised me. It just goes to show how small changes can sometimes make a big difference. Not always good for over all sound.

Ron

Here is Stevens original link

for the G68 power supply mod

http://www.audiocircle.com/circles/viewtopic.php?t=27713

Ron,

I totally agree MRC is not the only thing that will tighten bass. But to my understanding it should give you a pretty good signature of what you are getting.

Even if there was a difference I can see a debate now debating over which is better :-)

Debating is fun. I was surprised how fast that last one took off out of hand. Yikes! Like wild fire. We can't all agree. We all have our own opinions base on our experiences and knowledge. We just all need to show respect for each other even when we don't agree. For the most part I think we do. This is the best forum I've ever been on. Other than a few posts going sour it has been fun here. There is a lot of good knowledge here.

Cheers,

Ron

What I would like to know is since switched mode power supplies are known for the amount of RF noise that they produce whether it would be benificial to perhaps focus on a linear type power supply.

Having seen the guts of the G68J and G68D I know that there's plenty of space in there.

Any thoughts on this?

Cheers

Richard

Like was discussed in the previous thread it might just be overkill.

The PCB regulators, filter caps and good circuit design might make a more expensive power supply moot.

I certainly respect Stevens opinion that he heard improvements. And his review raised my eye brow, but that's it. I'd personally like to see more structured tests.

Merdian didn't use a solid gold cabinet either? Would that be overkill?
Merdian has never tried to be a Krell with 1/4 inch steel and 1/2 thick aluminum face plates. Their focus is on correcting errors in software and other clever circuits.

I'm not saying a better supply wouldn't help but there are certainly reasons why it might not be needed.

All of these "Do mains cables/PSUs affect sound quality?" type discussions are doomed to founder in disputes because the effects are very subjective and, as mentioned above, probably can't be practically measured. All you can say is that, to your ears, the sound is "different" using alternative components.

I am not sure what is "better" or "worse" any more - I just know what pleases me and I have no wish to enforce my opinions on others.

Hi Malcolm,

That's a good point but one key aspect here is the sharing of that knowledge so that you have at least some idea of what is or is not working for others....giving you the options.

OTT e.g. if a whole stack of Hiker's here all agreed that putting an apple on top of your player made it more amazing, you probably would try it

You wouldn't need specs for it (or maybe you would ) but ultimately only your ears would be judge.

Point is really (for me) that it's good to know what options are available. Some we will dismiss, so we will try and reject and some we will adopt in our systems.

How we dismiss an option or idea is the where it went wrong this week.

I agree with Malcolm on this. I'm amazed that the outcome of modifications/tweaks are assessed in such a subjective and unscientific manner. I don't think MRC plots are the answer either, as they are just too variable to provide any meaningfull comparative data. Blind listening tests(with n= >10) are the only way determine if what your ears are receiving has changed in reality.

Cliff