Boss GT 8 Effects Processor Service Manual

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2 Dec.2004 CAUTIONARY NOTES User data status User data status after each of the following processes is described below. Whenever carrying out procedures that involve deleting or erasing user data, always be sure to back up the user data to some form of external media (refer to Saving and Loading Data). *Executing Test Mode during Factory Reset deletes the user data. PARTS LIST Due to one or more of the following reasons, parts with parts code ******** cannot be supplied as service parts. -Part supplied only as a component in a complete assembly -Copyright does not permit the part to be supplied -Part is sold commercially CIRCUIT BOARD NIU meant that "NOT IN USE " there don't set any contents in the Circuit Diagram. There has silk-screen only in the Circuit Board. SPECIFICATIONS GT-8: Guitar Effects Processor AD Conversion 24 bit + AF method DA Conversion 24 bit Sampling Frequency 44.1 kHz Program Memories 340: 140 (User) + 200 (Preset) Nominal Input Level INPUT: -10 dBu RETURN: -10 dBu Input Impedance ΙΝΠΥΤ: 1 Μ -�� RETURN: 220 -�� Nominal Output Level OUTPUT: 0 dBu SEND: -10 dBu Output Impedance OUTPUT: 2 k -�� SEND: 2 k -�� Digital Output EIAJ CP1201, S/P DIF Dynamic Range 100 dB or greater (IHF-A) Controls < Front Panel > PATCH LEVEL knob (PREAMP/SPEAKER) TYPE knob GAIN knob BASS knob MIDDLE knob TREBLE knob PRESENCE knob LEVEL knob On/Off button TYPE VARIATION button CHANNEL button SOLO button SPEAKER button (OVERDRIVE/DISTORTION) TYPE knob DRIVE knob LEVEL knob On/Off button TYPE VARIATION button (DELAY) FEEDBACK knob LEVEL knob On/Off button TAP button (CHORUS) LEVEL knob On/Off button (REVERB) LEVEL knob On/Off button (COMP) On/Off button (EQ) On/Off button (WAH) On/Off button (LOOP) On/Off button (FX-1) On/Off button (AMP CTL) On/Off button (FX-2) On/Off button (MASTER) MASTER button PATCH/VALUE dial PARAMETER buttons OUTPUT SELECT button EXIT button WRITE button SYSTEM button EFFECT CHAIN button NAME button Process User Data Checking Version number Preserved Factory Reset Deleted System Update Preserved Test Mode Preserved

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3 GT-8 TUNER/BYPASS button CTL/EXP button VARIABLE button MANUAL button BANK pedals Number pedals CTL pedal Expression pedal Expression pedal switch OUTPUT LEVEL knob POWER switch Display 16 characters, 2 lines (backlit LCD) 2 characters, 7 segment LED Connectors INPUT jack OUTPUT jacks L (MONO)/R PHONES jack SEND jack RETURN jack AMP CONTROL jack SUB EXP PEDAL/SUB CTL PEDAL1,2 jack DIGITAL OUT connector (coaxial) MIDI connectors IN/OUT AC Adaptor jack Power Supply AC 14 V; Supply AC adaptor (BOSS BRC series) Current Draw 650 mA Dimensions 515 (W) x 261 (D) x 75 (H) mm 20-5/16 (W) x 10-5/16 (D) x 3 (H) inches Maximum height: 515 (W) x 261 (D) x 107 (H) mm 20-5/16 (W) x 10-5/16 (D) x 4-1/4 (H) inches Weight 4.8 kg/10 lbs 10 oz (excluding AC Adaptor) Accessories AC Adaptor BRC-240AT (#G2457142) BRC-230T (#G245714101) BRC-120T (#G2457144) BRC-100T (#G2457143) Owner's Manual English:(#G6047002) Japanese:(#G6047001) Read This First (leaflet) (#G6047005) USER Patch List (#G6027108) PRESET PATCH LIST (#G6027107) Roland Service (information sheet) (#********) Options Foot Switch: FS-5U, FS-5L Dual Foot Switch: FS-6 Expression Pedal: EV-5 (Roland), FV-300L Foot Switch Cable: PCS-31 (Roland) (1/4 inches Phone Plug (stereo) - 1/4 inches Phone Plug (mono) x 2) MIDI IMPLEMENTATION ENGLISH: (#17041558) JAPANESE: (#17041557) *0 dBu = 0.775Vrms *In the interest of product improvement, the specifications and/or appearance of this unit are subject to change without prior notice. *AF Method (Adaptive Focus method) This is a proprietary method from Roland & BOSS that vastly improves the signal-to-noise (S/N) ratio of the A/D and D/A converters.