Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems 568 digital volume issue

In the spirit of Halloween, I'm reanimating this thread to report some developments. I finally sourced the right kind of DIN plug and cobbled together a "DSP33 Reset Plug". Weeks passed, as the speakers are in a remote location, until a visit was planned.

I immediately pressed the Reset Plug into service, and noted a set of apparently happy blinks from the DSP33 LEDs which I assume indicated success. And when the system was awoken from its long slumber, all worked well.

HOWEVER, after a while the problem reappeared, with the volume control mostly ignored by the speakers. Upon examination, I found the Meridian 568 quite warm, with the components directly above and below adding a lot of heat to the 568. I moved things a bit to give the 568 some breathing room, and the volume situation improved. Not perfect, but good enough. The volume is still controlled in fits and starts, with the DSP33s responding only after the volume has moved by 8-15 notches.

So, it turns out to be a 568 COMMS issue that is temperature sensitive. When stone cold, it works perfectly. When at average operating temperature, it's usable but imperfect. When extra warm, it's quite bad. The DSP33 reset was a red herring. Strange, eh?

Cheers,
Roger

When I stacked my 500 kit, I raised the feet of my 568 to give a bit more airflow - iirc the grill for the optional fan is below. I cannot temember why I did it, but probably prevention being better than cure and the original feet were in need of a bit of tlc.

Ah yes. Feet. Mine came from the previous owner with none, so the poor thing was sitting RIGHT on top of a toasty piece of kit below.

Planning a new cooler spot for the 568,
Roger

Yes please do it.
The 568 insides get quite warm, even hot: the regulators stabilise around 60ºC (I measured up to 65ºC inside) thus several elcaps will shorten its life a bit.
Regards,
Josep

I just wanted to mention that I was able to find a new shelf for my feverish 568, and the strange volume issues have been solved. Sincere thanks to all for your help.

Happy new year,
Roger