Keeping It Real

I recently did a couple of repairs for a the son of a long-time hi fi customer. The pair of them qualify as full-blown Audioholic HiFi Addicts, each with their own spin on the hobby and each willing to invest in fine gear when they come across it.  In particular he had recently bought a dead-mint MC260. This legendary amp is famous for its build quality and the high specs it meets for distortion, minimum phase shift and wide frequency response. They were famous for putting other so-called HiFi products to shame once the test gear rolled out and measurements were taken.  The MC260 is two 30-watt amps on once chassis with a lot of flexible input configurations. These are full-differential, mostly DC-coupled amplifiers, which requires a lot of extra housekeeping power-supply wise to achieve. This example was near perfect – scratchless, no corrosion, near perfect lettering, etc. He is the second owner. The original McIntosh-branded tubes still graced the unit.  My job was a complete re-cap and setup using reproduction NOS type parts he bought as a kit from a well-known Mac website.  This included 4 twist-lock FTP multi-section cans, which are difficult to remove without damaging anything,  and expensive to purchase new, like $40+ each, dealer net.   The work is painstaking – everything needs to look like factory work when you are done, and to that end we made a lot of pictures before we ripped out parts to replace, so the wiring and placement could be made as close to original as possible. Afterwards, we verified all the voltages per factory, and cleared up a few minor issues that we found  by voltages or resistances being slightly off published factory spec. We then hit the distortion meters and verified both channels met the spec conveniently printed on the side of the amplifier. If you look close on the shot of the distortion meter, you will note that it is set to 0.3% full-scale, and the amp is running about 0.09% at full output. What a cool piece of hardware!  You just don’t find vintage gear this clean very often. This is HiFi to the core.