Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Power supply upgrade

Hi Albert, sorry for the late reply. Yes, I did install a 105W supply in one of my 861's, and it sounded fantastic. Good as the G68/LPS is, the 861/LPS is clearly better. However, fitting the 105W supply was difficult. It may just have been a learning experience for me, but the space taken up by the capacitor board made it difficult to fit the LPS mountings. If you wanted to go that route, I would make very sure that its all going to work. In particular, its important to be able to install and remove all the electrical and mechanical interfaces with the PSU in its installed position. On the whole, I would recomend the CP498 for the 861; there's really not much wrong with that. If you fitted a CP498 you would be be very happy with it.

Regards, Nick

Thanks Nick.Not late at all.I'm going to make it external.I have customized the case of my external power.I will post some pics once it finish.

Hi all

I've got a Meridian 800DAX v4 with a dying power supply. The power supply still works but, after reading these pages twice, I'm figuring that I have a 5 Volt issue.

Nick, you said that these units need 5.2 Volts I believe and that even the act of metering the 5 Volt line sometimes interfered enough with the voltage as to stop the Meridian unit from properly starting up. Well, that's what my symptom looks like.

My question is, won't the new linear power supply I choose need to be adjustable enough to be able to get all the way up to 5.2V DC for it to work?

A Power supply I'm considering is a Acopian type but the 5 Volt adjustment is only 0.5 Volt. Should I assume this adjustment isn't enough and that it won't work?

Thanks in advance. HUGELY helpful thread

Tas

Hi Tas

If the PSU will go to 5.5V, then you're covered with room to spare? I'll let the experts answer, but I'd have thought that 10% adjustment on the 5V line is quite a generous margin?

Cheers

George

Hi George,

Thanks for the speedy reply! Your comment makes complete sense and, based on everything I've read here, I figure you're right.

Now that I re-think my question I realise I've made a mistake. I need accurate -/+12 Volt and 5.2 Volt power. Both the HDCC-150W-A and the Acopian supplies will do that. My mistake... sorry.

I'll go sit in the corner now!

Cheers, Tas

Tas, if you want to go up to 5.2V, I think you have to fit a voltage limiter to the display. See the Meridian technical paper on changing SMPS. I would stick to 5.1V. All PSU's should give you that control, no problem. The Acopian supplies look to be very good (but I bought a 115V version for myself by mistake

Nick

This is correct. There is a watchdog IC that is retrofitted in place of an existing capacitor and the center leg is hardwired to a trace. This is to keep the display from locking up if I recall correctly.

I was aware of this voltage sensitivity a long time ago and I think now as I thought then that it is poor electronic design to require such close tolerances in commercial hi-fi equipment. It's asking for trouble. You only need a bit of drift and your reputation is damaged.

Gentlemen,

Thank you very much. I was indeed wondering about that particular issue of the watchdog IC. 5.1 Volts DC it is!

Just on the Acopian Power Supply, in case anyone here is interested, I bought my new 250 Volt supply from a US eBay seller who got these boxes from a local Areospace company sale. The two units he has (both are 3V51212T11A which is the 120 Watt, overvoltage protected, version) retail from Acopian for $US600 each and I offered this seller $US65 which he accepted. Yes, I said $US65! I couldn't resist despite the fact that my first preference would've been to have used a FG Tektronik NMC 105 supply internally.

In case anyone is interested, this seller has one more Acopian PSU remaining.

The price is a huge bargain. Hope someone here can make use of it.

Thanks again everyone for all your help. I'm indebted

Tas

I love my G91A very much, is there a LPSU solution for it?

Nick,

The CP498 LPSU you recommend seems to be discontinued. What is the next unit you would recommend?

All the talk of failing power supplies has me worried and I think I should upgrade the PSU in my 861v4 before it blows and takes other circuits with it.

I'm looking into the health check, but at $1,000 plus labor and shipping, it seems like a steep price. The 5 year warranty would be nice but at this price, I'm not sure if it's worth it.

I think it's a very fair price, upgrade to a Meridian spec LPSU and have piece of mind for the next 5 years. Also it improves the units value should you wish to move it on at a later date.

Personally if I were in the market for an 861v4, I'd prefer one with a Meridian Linear PSU than a 3rd party one.

Regards,
Carl