Vacuum Tube Warm Up; Rear Panel Inputs And Outputs - DYNACO Stereo 80 Owner's Manual

Vacuum Tube Warm-Up
Although a vacuum tube power amplifier begins to work in as little as 15 seconds after being switched on,
it is important to allow a 3 minute warm-up period before using the amplifier.
Output tubes can be slightly damaged each time they are forced into use before being warmed-up,
resulting in non-optimum sound and shorter tube life. If one listens to music during the warm-up period,
one may notice that the output volume of the amplifier changes as the tubes warm up.
We recommend that you wait at least 3 minutes after switching the amplifier on before using it. On the
Stereo 80, waiting about one minute after the four bias lamps turn from "green" to "off" is a proper
(minimum) warm-up period. (See section entitled Bias Adjustments - general)

Rear Panel Inputs and Outputs

Inputs
There are two input jacks located on the rear panel of the amplifier - labeled Left and Right. These
connect to your preamplifier Line Outputs.
Never plug in, or disconnect, interconnect cables from other components to the
amplifier when it is turned on. To do so could cause a fuse to blow or even damage the
speakers.
Outputs
Match the impedance of your speakers to the amplifier by connecting the positive (+) speaker wire of
each channel to its corresponding 2 ohm, 4 ohm, or 8 ohm red binding post. Connect the negative (-)
speaker wire from each channel to its corresponding black binding post.
You can safely connect or disconnect speaker cables to/from the amplifier while it is turned on. It is best
at those times to turn down volume control(s) on any equipment connected to the amplifier inputs.
(Nevertheless, care should be taken to not touch bare speaker wires together if one end of the speaker
cable is connected to the amplifier.)
4