McIntosh MC275 Amplifier

"The original McIntosh 275 is the most desireable piece of vintage audio electronics originally available to consumers on the collector market today. Their value is substantially cosmetic and this unit should hold up much better than the original in terms of appearance, as it is stainless steel and is polished or quality triple-chromed (depending on version.) However, the circuit is simplified, the transformers are of a much less expensive construction method and the circuit is built substantially on one PCB, which has been proven troublesome in the past on guitar amplifiers and in Audio research and other very expensive high end amplifiers as well. Given the price of this unit I suggest spending a little more on a mint original, or a little less on a rusty one and having its chassis rechromed to CCCA standards by a automotive chrome shop."

"Thanks for asking these questions. If you look at a schematic of the reissue of the MC275 you see there are only two and not three windings for the primary. The new transformers are an EI laminated unit and are wound by Schumacher on early ones and inhouse on later ones but they are NOT interchangeable and Mc will NOT sell the new one as a part because it won't fit the old ones.

The originals are C-core wound using quad formvar wire for the primaries.

Putting power tubes on pc bards is a proven principle for disaster as anyone who has had to work on modern guitar amplifiers can testify. ARC does this and they have had some massive failures too.

That 90% of high end audio saloon products have went this way is a sign that cost cutting has put any consideration of longevity aside. PCB construction is only marginally compatible with vacuum tube circuits using any substantial voltages and currents."