Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems DSP life expectancy

Also, if those black caps are a different brand than the light blue caps, maybe somebody was there before you. The trace on the bottom of the PCB my have burned up, requiring a jumper. I would replace all those electos. Most of the original ones around the regulators will test at a fraction of their rated value.

I don’t think it was repaired. There is an ADDed transistor there !!

I plan to open it’s sister to see if it has the same mod.

Looks like a factory change from new to me.

By the way the S/N is 306245 in the photo above.

Transistor? Huh. That sounds custom. ha.

That transistor is in 4 different DSP5000's bought from 2 places. One pair bought new direct from Meridian.

I just checked another pair, S/N 305805 and it has the MOD too.

This photo shows the part number on the transistor. It's the small black transistor.

I didn't embed picture so you get the full resolution of original.

Image of added Transistor LARGE IMAGE

Interesting. If you find or make a diagram let us know.

I would replace the resistors with ones of the same value but a higher rating. The ceramics will be ok.

I used Kiwame 5W which are available in both 680R and 330R. The leads also fit through the holes in the board. Look out for lifting tracks and repair these at the same time.

Also while you have got the amp board off, replace the caps (electrolytic + 4 supersounds) as well. Not much additional cost or effort but well worth it.

The modification in your picture looks to be around the thermal shutdown circuit and not related to the power supply.

Email sent to the address in your profile.

I think we found the same Resistors Meridian uses (at least the same package).
I believe they are 4 Watt Wire Wound in a Ceramic Case.

I found them at Newark.Com (from UK Warehouse), DigiKey.com has one but not both in stock.

SBCHE4330RJ 330 Ohm 4W

SBCHE4680RJ 680 Ohm 4W

We also measured the Voltage going into the Regulator in Standby and Not Loaded.

With 680 Ohm it's like 33 Volts.
With 330 Ohm it's like 39 Volts.

The output, which is what matters was 15V in either case.

The regulator Max Input Spec is 37.

In case anyone hasn't seen what this looks like.

Wound needing attention



In Surgery Prep

Nice one Doctor DSP.

Awesome work and great to have the photos on the site. I replaced them on my smiley 5000s and was surprised by the range of 'burning' on those resistors. One pair was pretty bad, the other not so bad.

I have an old pair of 18-bitters that are pushing 30 years old and those resistors still look great. I wonder why the resistors on the 24/96 seem to go bad faster?

We are also wondering why the 18bit ones don’t fail. Mine look perfect too.

Has anyone replaced the amps in the 5000s? Any suggestion for replacement parts?