John Warren

The inconvenience and expense is what attracted me to tube amplification.

The 1979 collapse of Advent. Advent Corporation Leaves Cambridge | News | The Harvard Crimson (thecrimson.com) And its headquarters before leaving for New Hampshire (it was on life support a few years before the move). After about 1976 or so their products weren't great. Cambridge was too expensive for manufacturing even back then.

In 1964 this building (today) was once the home of Acoustic Research (AR) 24 Thorndike St., Cambridge, MA. They also occupied 21 Thorndike a bit of the way down the road. They had a showroom there too.

McGee Radio Co., 1901 McGee St., Kansas City, Missouri. 1964 catalog. Then: And now:

I was at the Capitol Audiofest last year and the crowd was mixed, large fraction of over 50 but young folks too. That said, there was much more to choose from in the 60s, 70s and 80s. The extremes today are better than those during the vintage years. The real high-end loudspeaker systems today are just at a different level, way, way better drivers and enclosure materials.

Raw birch veneer.

Paint or veneer.

Boron is not a RE, it's classified as a Metalloid.

Here's an example of using a distortion analyzer, one channel is not behaving. The trouble channel will output 5VRMS with 1%THD. A listening test alone would not catch this given 5VRMS can be quite loud and <1%THD isn't terrible for a tube amp. It will show up in the tube pin voltages however as a significant departure from SM requirements.

Recently completed 240. Was in rough shape. Kept the transformers, boards, pots and switches and bottom chassis cover, just about everything else replaced. Sometime in its history the original films were replaced with Multicaps. Other past modifications performed on it caused addition headaches as well. For those of you considering restoring your MC-XX or MC-2XX the service manuals provide expected DC voltages at each tube socket pin, no signal applied at the inputs. If you do not have access to a distortion analyzer, rating the voltages with a Fluke or bench top DMM and writing them down is the next best thing and, if there's significant deviations, the %THD will suffer. Presuming they're within the ranges identified and your tubes are in reasonable condition, your amp should perform with low distortion.

This forum was the first I migrated to after giving up on Usenet. The unmoderated rec.audio newsgroups became toxic, flame wars. Every thread degraded to a shouting match.

He's looking for work? Also, not all cabinet shops do veneer work, they source it to outside suppliers. Does your bud do his own veneering? Does he know how to match veneers or source the right stuff? Reason why I'm asking is I've had issues with suppliers I've worked with in the past. They're used to making kitchen cabinets but have little appreciation for the details needed for "structural" loudspeaker enclosures.

Mineral spirits or Turpentine will work well. Both are very pungent, but Turp isn't as toxic.

Home entertainment setups w/large screens, cable TV interconnects, active subwoofers, and main power amps (2, 4 and 6 channel) can get noisy if 3-prong power cords from various components are plugged into different wall sockets. The Jensen transformers break loops that can occur from this sort of thing. They're broad bandwidth, low distortion, work well.