Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems 565 cracking static type noise from rear DSPs

I have just started experiencing issues with a cracking static type noise coming from both my rear speakers.

Currently running a full 24 bit digital theatre with 500 transport into 518 and 565Z3 with 5500 fronts, 5000HC, 5000 rears and 2 x analog REL subs.

I have tried new cables from 565 to rears and also setting the 565 with sides to check the output.

The static noise is there on both outputs and gets louder with volume increase. When doing a calibration test the white noise is distorted and quieter than it should be. DSP5Ks are both fine.

Any ideas what to try next?

Hello, and welcome to the forum.

Have you made any other recent changes to the system, eg physically moving the kit around etc?

If it's been working normally and stable up until now, and this problem has just appeared, I think I'd get in touch with MrTechGuy (official Meridian service agent for legacy kit) here on the forum, as it does sound like a fault. Especially given the age of the 565.

Cheers

George

Hi Andy and welcome to the forum.

I vaguely remember having a similar issue many years ago but cannot recall the cause or solution. It sounds like a digital locking issue.

Perhaps you could provide a little more information?

What sources are causing the issue? Is it normal red book CD or an AV source with DD or DTS?

What setings do you have in the 518? It is possible to confuse the 22-bit 565 but I doubt it would cause the crackling.

Have you tried swapping over the rear speakers (in case it is a connector issue)?


Supplemental - have you tried different mains outlets for the rears - if the cracking tracks volume that could be an amplifier issue but it is unlikely to affect both at once..

Hello all,

Thanks for the responses.

My 518 is only been used with the 500 transport (my G98 DVD is currently out of action as the CD/DVD drawer is not opening). This is done with digital in and digital out. Settings on 518 are for 24C and noise shape D. I noticed it last night when listening to a CD and changing the DSP modes on the 565 to ProLogic by accident.

Today I was using sources from Sky Q and my LG TV via optical directly into the 565 via a splitter.

The 5Ks were retired to rear duty when I bought some Smiley face 5500s (from a nice chap on this site) back in December (which are stunning). At the time there was some of the same crackling/static but only on one rear Chanel and by the end of the first day of set up it had gone. I have not moved anything for the past 5 months and all was working as it should.

The previous set up used analog rears with two separately fed Rotel Monoblocks feeding my Dynaudio Contour speakers.

Scratchy head moment as I am not sure what else to do. I was going to ask a mate who has a 565 he is not using to do a test before either looking at repair or replacement.

Thanks again for your help on this excellent forum.

Hi Andy,

May be worth temporarily swapping fronts and rears and see if the problem stays with the speakers or with the rear outputs.
You need to work out if the speakers or the processor is the cause of the problem.

Have you ever had the speakers serviced? Crackling noises from DSP5000s could be the start of the breakdown of the load resistors.

Let us know how you get on.

Cheers,

Steve

Hi Steve,

I have switched the output digital lead from the front speakers and switched them around so the input to my rears is the front and the visa versa the front being the surrounds. The rear 5Ks work perfect with no static noise at any volume level. When changing the DSP mode to any surround setting the 55Ks work and sound as they should if they were rears with no static noise. As soon as they are changed back then the static noise is back on the 5Ks. (BTW the noise is very unpleasant and distorted).

So I have proved that the 5Ks work as they should in Stereo and Surround and that the output from the 565 is also working.

Have also reset the 565 with Type 3 and the input today was from the 500/518 digital, so also proved the optical input is fine.

Where to go from here???? Any more ideas?

Thanks for any input.
Andy

Hi Andy,

The only thing I can think of is that one of the cables could be suspect or a possible problem with the I/O board on one of the speakers...

Have you tried re-routing the cable to the 5K's? Just ensure it does not go anywhere near mains cables.

Also, try swapping the 5K's and re-type them (i.e. Left Slave becomes Right Slave and vice versa). Could be the I/O board on one of the 5K's playing up?

Not sure what else to suggest...

Please keep us posted.

Cheers,

Steve

Hi Andy

If your tests suggest that the 5ks, 5.5ks and 565 can all play normally, I think I'd agree with swpnt that cables may be at fault?

When you swapped cables, what ends did you physically move? Was it just a swap round of plugs/sockets at the rear of the 565, or moving the DSP ends by dragging them across the room to switch fronts and rears around?

I'm just wondering if the cable movement has reconnected a dry solder joint or something?

Cheers

George

Hi George/Steve

When I tested the rear 5Ks I just changed the lead at the 565 end and plugged them into the digital front out. That qualified the digital cables working. I did check the balance control L+R in either direction. I have tried 2 x other digital cables from the 565 to the 5Ks while leaving the coms on the existing (buried) cables with no joy.

As suggested by Steve I have re-typed both the 5Ks as the opposite to what they are (LR Surround slave to RR Surround slave and the noise has gone. When I put them back to normal and re-typed, the horrible distorted static noise was back.
Changed them back to the wrong way around and all good again with no noise.

Really confused now. Might swap the two speakers over manually tomorrow to see what results this brings. The mystery continues.

Thanks all for your help so far.

Andy

That's really weird. I have no idea but the process is interesting.

Best of luck

Neil

Hi Andy,

Very strange... Sounds like one of the DSP5000's may have an issue, although as you've only re-typed and not physically moved them, I'm scratching my head!

Do try physically swapping them over and re-typing and see if that resolves the issue.

Cheers,

Steve

Have you tried running directly out of the 500/518? What is the result. If it is the same the speaker is the issue, if not it is the 565