Page 43 - The Art and Science of Analog Circuit Design

We Used to Get Burned a Lot, and We Liked It

inches and the other components sprawled in a two-inch mat below the
chassis.
Transistors made construction more two dimensional. The transistors
weren't tall, generally the size of our TO-39 package of today, and circuit
boards were practical since they didn't have to support heavy or hot com-
ponents. All passive components became short too. A layer -of transistor
circuitry thinned to one inch or less. There was a volume reduction of
about 20:1 over equivalent tube circuits. For industrial electronics, how-
ever, transistors afforded only a 2:1 overall product cost reduction,
In the 1960s, the quality of cabinets really degraded. Transistor equip-
ment was considered cheap, relative to tube gear, and only received
cheesy plastic cases. The paint and decals on the plastic rubbed or flaked
off, and impact could shatter it altogether. Tube equipment, on the other
hand, had enjoyed quality wood casings for decades. Since the tiibe chas-
sis were so large and heavy, furniture-quality cabinets were needed sirn-
ply to transport the electronics. The radios and TVs were so obtrusive in
tube form that manufacturers really made the cabinets fine furniture to
comply with home decor.
Quality in the tube years came to mean both mass and the use of pre-
cious materials. Greater mass meant you could transport or physically
abuse the equipment with no damage. It also meant that the components
would suffer less from thermal changes and microphonics (electrical sen-
sitivity to mechanical vibrations). A really sturdy chassis would not need
alignment of the tuned circuits as often as a flimsy frame. Precious mate-
rials included quality platings—such as chrome or vanadium—of the
chassis, to avoid corrosion and extend useful life. Heavier transformers
allowed more power for better bass response and greater volume. A heav-
ier power transformer would bum out less frequently, as would oversize
power tubes. Components came in quality levels from cheap organic-
based resistors and capacitors that cockroaches could eat to more expen-
sive and long-lived sealed components. The general attitude about
electronics construction was akin to furniture: the more mass and the
more precious the material, the better.
Since the transistor circuits had no thermal nor microphonic problems,
the poorest of cases were given to them. They weighed next to nothing,
and a hard fall wouldn't cause too much damage. Since the products had
no mass nor special materials in their construction, people thought of
transistor products as low-quality. The manufacturers made sure this was
true by using the poorest materials available. The circuit boards did in-
deed tarnish and warp, and the copper could crack and cause opens. The
wires soldered to the boards seemed always stressed from assembly and
often broke. Even the solder had corrosive rosin.
Because the transistor circuits were small, the traditional soldering
guns and irons were far too hot and large to use; we now had to buy new
small irons. We even had to get more delicate probes for oscilloscopes
and voltmeters. These problems were moot; you couldn't effectively
repair transistor stuff then anyway. Even if you could troubleshoot a bad

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