High Level
Inputs
(Oval Key
selected)
Main Outputs and Mono switch
The usual ground thumbscrew is provided for
IRIS has seven pairs of main HIGH LEVEL inputs, selected by the seven (oval) KEYS to the right of the phono KEY. All of these inputs proceed at unity gain to the
All of these basically identical inputs are selectable by the input KEY switches. The KEY switches activate a digital system which effects
Excepting phono, all input impedances, for the entire preampli- fier, are in the
To get you to the basic operation of IRIS as quickly as possible, we have deferred the discussion of EPL and TAPE loops to a later section.
The MAIN output jacks are used to feed the power amplifier. Their low output impedance of 316 ohms allows driving long cables if necessary.
The MONO switch effects a passive combining of the stereo channels into monaural, fed through the attenuator system to both line amplifiers. Although rarely used today, this switch is provided for the optimum reproduction of treasured mono recordings, and can be employed to check for exact system balance.
It is highly recommended that where you may have a constant monaural source, such as a mono TV, that you secure a “Y” splitter from an electronics store and feed both preamp chan- nels in parallel. This makes remote operation easier, and avoids accidentally leaving MONO engaged when you switch back to a stereo source.
