For sale is a McIntosh MC-2150 power amplifier capable of a continuous 150WPC into an 8 Ohm load or 300W mono! This is a very rare power amplifier - only around 390 of these were made for the 5 years they were produced (1982-1987) with this one being a slightly later example. This design includes the super cool built in tester on the front that counts down quickly through a handful of self-tests before allowing any output to the speakers. This is not our first time encountering this type of Mac design and thus we know how to rebuild these boards as well as the rest of the circuits/boards in these old McIntosh designs so that they will continue to work exactly as they should for many years to come! More details as well as details of the cosmetic and electronic restoration are discussed below.

There are not a lot of reviews on this amplifier but in all reality, it sounds exactly like all of it's other cousins from this era (in a good way...they all kicks serious ass!). There are many amps that share essentially the same driver boards underneath and very similar power amplifier designs/output stages that are used throughout the 80's Mac power amplifiers. This amp sounds like the MC-2255 we restored fairly recently as well as the MC2250, MC2120, MC2125 and other amps that share the same second-generation McIntosh solid state power amplifier design - albeit we consider this version more of a 3rd generation or later revision of the second generation designs with the built in self tester. But again, these are all actually very similar amps that all share the same driver boards and common driver board issues which we know how to address and prevent many potential future issues!

Cosmetically the amplifier is in fantastic mint condition really with really just the tiniest little faceplate mark on the bottom towards the middle and a few marks on the transformer stickers...Really you've got to be nitpicky to find the issues with this bad boy! We purchased it from the original owner which is always our preferred method for acquiring gear...especially when it's been so obviously well cared for!

Electronically the amplifier first was disassembled and all board are clearly labeled and then removed. The first thing we do is attack the driver boards - we replace all electrolytic and tantalum capacitors throughout as well as any other obviously heat stressed components...and then we flip the boards over and touch up every single solder joint throughout. The solder is a big issue on the boards from this series as well as the edge connector solder and even though it's a tedious task with such densely packed boards...we've fixed many issues on these amps by simply going over all of the solder and flowing in some fresh leaded solder after recapping them.

Next the front panel boards were addressed - really specifically the power supply board that also drives the front panel countdown/self test setup as well as the power supplies for various lower current sections of the amp auxiliary circuits. This board was first completely recapped, then had any heat stressed components replaced as well as upgrading a few transistors to modern more reliable types where needed. Lastly, as was done with the other boards, all solder was touched up because these 80's Mac's seem to have a lot of solder-related issues.

The green lamps are replaced with LED's and the limit lamps are replaced with new correct voltage lamps. This circuit does not like LED's for the limit circuit and they shouldn't be lighting up ever anyways after the initial turn on unless you're really pushing the amps limits :)

The main filter caps still tested perfect which is our general experience with these 80's Mac amps - the ones in this amp are testing above their rated capacitance still and ESR/dissipation factor are well within spec. In circuit performance verifies they are still perfectly sealed and performing flawlessly with zero hum audible ever from the amplifier even into our most sensitive speakers.

Lastly the bias and DC offset were checked and touched up as needed to get everything performing to it's best abilities. The amp performs flawlessly in all aspects after restoration and really is a truly incredible performer that captures the beauty of the McIntosh autoformer output stage beautifully. This beast of an amplifier is plug and play ready to go for many years to come. All controls are carefully cleaned for dropout free operation and all performance aspects are verified both on the bench and in our personal system.

The amplifier will be shipped carefully so it arrives as it left here. We put a lot of work into restoring these amps and always ship so that even the heavy handed carriers can't hurt anything. We know how to package these amps - similar to how McIntosh does for many amps - by putting the top side down so all of the weight (the power and output/auto transformers) is towards the bottom of the package - and everything is carefully fitted so that nothing can shift around in the box.