Monday, October 6, 2008

The Hurrier I go the Behinder I Get

I am hopelessly behind in posting my restoration efforts. I was missing a camera for a few weeks... Waiting in the wings are write ups for the Marantz 2230, the Nikko 815, the Toshiba 330 pre/power pair, and the JVC JR-S200 receiver. Oh, and I forgot: the Marantz 115B tuner, part of a set with the 3600 preamp and the 250 power amp, both awaiting the soldering iron. Oh, and the Advent 300 restoration shoot out awaits. So, consider this next item an apertif: the Realistic Minimus 1 speaker.

Orion says the Minimus 1 was produced from '69 to '73, my college years! While the Minimus 7 is a common item, this pair of Minimus 1's is the only pair I have ever seen. Maybe I don't get out enough. But doing a bit of research on ebay shows that in the last 90 days 270 7's have been auctioned, compared to only a single pair of 1's with blown woofers. That's rare.

Yes, that is real walnut veneer. They are slightly larger than the Minimus 7, well built but with something funky going on in the back:

Note the 3 posts: you can augment the high frequency balance via strapping the middle post. Here is what is going on inside.

This is looking through the woofer hole at the crossover. The 3 posts are visible, although a bit obscured with polyester fuzz. The post at the right, missing the screw, hence the dark center, is actually the leftmost, positive terminal. (Remember, we are flipped!)

There is a 6.8mfd cap on the tweeter. This was my reason for being here, one of the pair was a bit dull sounding, so presumably one (or both) of the caps was aging. Both were replaced with film. And I managed to keep the burns to a minimum in the tight space, thanks for asking.

The crossover is a second order on the tweeter with a wire round resistor taming it a bit. The tweeter coil is actually at the far left in the picture. The woofer filter is a first order (ie. just the coil at the right) but strapping the middle post adds the wire wound resistor at the bottom to dial the woofer back a bit. 'Increased' high frequency is really diminished low frequency. So, back in the day your $60 bought you a nicely finished two way with 5 components in the crossover. In just a few years the trend would be a single cap on the tweeter and zip on the woofer (eg. the EPI 100.)

The Minimus 1's have a solid following on ebay with good reason. Working pairs seem to go for about $75, a bit more than their original cost in the early '70s. They look great, very '60s-ish with the sparkle cloth grill and very well done veneer. They are very musical performers despite limitations at either end of the spectrum. The woofer quality is such that I have wondered if it is scavenged for other projects. Buy 'em if you find them at your local thrift!

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