When choosing balanced input, please make sure the INPUT SELECTOR toggle switch, on the back of the amp, is closer to the balanced connector. Selecting Single Ended input, the toggle switch should be closer to the SE input connector.
There are TWO mono Gain switches on the back panel, one for each channel. Each has three gain settings, High, Medium and low. Both of the gain switches have to point to the same gain selected, if not, the balance of the sound will vary in your headphones.
Both balanced connectors, input and output, have identical pins configurations. Left Channel PIN # 1 is POSITIVE PIN # 3 is NEGATIVE Right Channel PIN # 2 is POSITIVE PIN # 4 is NEGATIVE
SR-71B has four Lithium Ion battery pack. It is custom manufactured to our Specs and comes with one year Warranty. SR-71B has life time warranty. Please fully charge the amp before use. Red LED on the charger indicates the battery is charging. Green LED on the charger indicates battery is fully charged.
Connecting SR-71B to a portable player with a single ended line out signal will provide both, a balanced output signal at the balanced headphone connector, due to the phase splitter circuitry, and the single ended output signal at the SE headphone jack.
If SR-71B is fed fully balanced signal from high quality CD player or DAC, it will process the balanced signal, all the way through, in balanced configuration via four independent channels and outputs fully balanced signals at the balanced connector. Single ended output is also active but provides SE signal at the SE headphone jack.