Phone 716 663-8820 . Fax 716 865-8930 . Email: Sales@whirlwindusa.com . 8S S8 Maximum Output Level +22 dBm Rise Time 6 uS POWER RL87 54321 INPUTS 120 Vac at 60 Hz 230 Vac at 50 Hz 25 watts MAX U.S. AUDIO A DIVISION OF WHIRLWIND INC ROCHESTER, NY USA MONO RIGHT/ : DEBRANCHER AVANT D'OUVRIRATTENTION LEFT MAIN OUT STEREO ALL CONNECTORS BALANCED TIP+, RING-, SLEEVE GND : TO PREVENT ELECTRIC SHOCK DO NOT REMOVE COVER. NO USER SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED SERVICE PERSONNEL. : TO REDUCE THE RISK OF FIRE AND ELECTRIC SHOCK DO NOT EXPOSE THIS EQUIPMENT TO CAUTION ANY TYPE OF RAIN OR MOISTURE. WARNING 6 Stereo Separation >60 dBm Minimum Headphone Impedance 30 ohms Noise One Channel Unity Gain-81 dBm All Channel Unity Gain -78 dBm 987 6 T.H.D. + n <.01% 20-20kHz Range of Gain Controls -60 to +18 dBm Mute Attenuation 60 dBm Total Gain 36 dBm INTRODUCTION THEORY OF OPERATION CONTROLS AND FUNCTIONS BLOCK DIAGRAM Power Consumption .15 Amps Max. A.C. At 120 VAC .15 Amps Max. A.C. At 230 VAC AC Dropout Voltage +105 VAC at 120 V nominal +205 VAC at 230 V nominal BUSSCHANNELVOLUMELEFTBUSSRIGHT LEFTTOPRIGHT MONOBOTTOM + _ + _ JUMPERSFOR120/230VOLTS 8. POWER SWITCH connects AC to the transformer primary and the POWERCHASSIS GROUND . AMPSLOWBLOWHOTNEG POWER LED +18 VOLTS DC-18 VOLTS DCBUSSLEFT BUSSRIGHT _ front panel LED indicates that the unit is working. Both sides of the AC green is earth. MASTERVOLUMEPHONEVOLUMEHEAD + 2. MASTER VOLUME CONTROL determines the amount of signal from + _ PHONESSUM AMPS 1. INPUT LEVEL CONTROL varies the amount of signal sent to the master left and right busses through a range of 60 dBm attenuation at full off to +18 dBm of gain full on. the summing amps that is fed to the left and right outputs. This also has a gain range of -60 to +18 dBm. 3. HEADPHONE VOLUME CONTROL varies the signal at the headphone jack. The signal going into the headphone circuit is pre master fader and independent of the master volume pot. 4. POWER LED indicates that the unit is turned on. 5. HEADPHONE JACK drives stereo headphones with impedances greater than 30 ohms and is wired with left to tip and right to ring. 6. LEFT AND RIGHT INPUT JACKS for each of the 8 channels are balanced 1/4“ TRS. For mono input, the right jack can be used alone and it will ”Y” the signal to both inputs. 7. LEFT AND RIGHT MAIN OUT JACKS controlled by the front master volume pot are balanced 1/4“ TRS and will drive balanced or unbalanced inputs. line are switched and the main fuse is located on the circuit board inside the unit. 9. POWER CORD has a standard 15 amp plug for 120 VAC and has no plug on the Mix 8S 230 VAC model. Black is line, white is neutral and TYPICAL OF 8 HEAD The U.S. Audio Mix 8S is a stereo line level eight channel mixer with separate left and right signal paths. Each of the 8 inputs has left and right balanced 1/4“ input jacks. For mono input, the right jack can be used alone and it will ”Y” the signal to both left and right busses. The signal is actively balanced through differential buffer amps and sent to gain circuits. Each channel has a dual element level control with a gain range of -60 to +18 dBm, allowing user control over a wide range of input audio levels. Unity gain is at the 12 o’clock position for both channel volume and the master volume. Signals from individual channels are summed together and delivered to both master gain stages and to the headphone driver circuit. The left and right master outputs are controlled by a stereo volume pot which has a gain range of -60 to +18 dBm. The 60 dBm of attenuation turns off the audio signal at the main outputs if necessary. The Mix 8S headphone circuit monitors the left and right busses and will drive stereo headphones with impedances greater than 30 ohms. The front panel stereo 1/4“ headphone jack has a volume control with a range of -60 to +18 dB. The signal going into the headphone circuit is a pre master fader. Careful layout of the circuit board and a star grounding scheme ensure no internal ground loops between channels and / or sections of circuitry. Using low noise components, noise is 81 dB below 0 dB at unity gain, with one channel up and 78 dB below 0 dB will all channels up at unity.U.S. Audio has made every effort to ensure that your equipment is Thank you for selecting the U.S. Audio Mix 8S stereo line mixer. This The Mix 8s utilizes a dual transformer power supply which is configured with internal jumpers for 120 VAC 60 Hz or 230 VAC 50 Hz operation.Please inspect your product for any signs of damage during shipping There is an internal fuse on the hot side of the AC cord, and the power switch makes and breaks both the hot and neutral legs of the AC cord.shipper. We recommend that you save your packing material for use in received in the same perfect condition it was when it left the factory. and report them to your dealer so that a claim can be made to the the unlikely event that you need to return yo...