Here is an image showing the output devices, with wired sockets for more transistors. It makes you wonder what it would take to "upgrade" this thing to a 333.
Made in USA!
The Mark Levinsons in the 33x series are known to be plagued by bad Phillips capacitors. However considering this is now a 20 year old, high power, ferrari-of-amps, machine; this is still pretty good. Even better news, is that you can replace these caps with super nice, USA made Cornell Dubilier ones. When the filter and supply caps start to go, you will, most obviously, start to hear the 60Hz hum from the mains. It is important to replace the capacitors immediately as there is a chance that the failing cap may explode or REALLY leak. Further, you don't want your mega buck amp to loose its peaks and raise its noise floor, you can get that anywhere!
I'll save you the save you the suspense. The "leak" was actually a dyna-mat type rubber sound dampener material stuck to the walls of the amp. I believe the failed capacitor was conducting to the opposite rail and over drawing one of the MASSIVE toroidal transformers, thereby causing enough heat to melt the rubber material and have it drip out of the machine.
Here is an image showing the output devices, with wired sockets for more transistors. It makes you wonder what it would take to "upgrade"
this thing to a 333.
This entire amplifier is built about the SIGNAL PATH, not assembly or repair. this thing is a maze of boards and components. Mark the order
and location of everything you take off, and mind your good practices for static electricity control.
I wrapped (and labeled) all of the nice anodized components to not mar them and aid on re-assembly.
Any transformer you will find in this amp is a toroidal one (marked Mark Levinson). It's just a magnificent amp.
I know they are all connected to the same rail, but DC test each cap, these are high energy devices. There should be bleeder resistors in the
circuit, but I'm not going to bet my life on it, nor my pain. If you do get a non-negligable voltage, get on the net and find out how to discharge the capacitors
safely. Like running the caps in to spikes separated by 6 feet of earth outside, gradually moving the spikes in. I do not endorse any method however. This are
dangerous devices. Further, if you are working on an ML 332 that has just been unplugged, the bleeders will not have had time to do their job. There will be
voltage.
Don't fight with these connectors, here's how you get them off: Neutrik D-Series XLR Connector
Mark everything! The order and the component's position. I wrapped all the anodized components in plastic, so as not to mar the finish.
Don't wrap any circuit boards though.
The new power supply capacitors are slightly taller than the originals. You're OK with most options as long as the caps you
choose are less than 6 inches in height. What you need to pay close attention to is the diameter when choosing the caps. I got a perfect match for the filter caps,
and the new power supply caps have only a slightly higher peak DC voltage and are a bout an inch taller.
Here is the Mouser order:
Mouser #: 598-3186GJ503M125DPA Mfr. #: 3186GJ503M125DPA2 Manufacturer: Cornell Dubilier Desc.: Aluminum Electrolytic Capacitors - Screw Terminal 50K Ohm 125Volts 20% RoHS: RoHS Compliant Availability 4 Ships Now $95.04 $380.16 Mouser #: 598-DCMX192T200AC2A Mfr. #: DCMX192T200AC2A Manufacturer: Cornell Dubilier Desc.: Aluminum Electrolytic Capacitors - Screw Terminal 200V 1900uF Case 1.375 x 4.125in RoHS: RoHS Compliant Availability 4 Ships Now $22.74 $90.96
Test the new caps for a voltage as well. I don't know if there can be a perfect static storm or not. Perhaps a guy playing a joke on you at
the factory... There was a small voltage (around 2) in one of the new caps I tested, I wonder how it got there.
