Boulder 1008 Phono Preamplifier Owners Manual V1.0 10/20/2009 Boulder Amplifiers, Inc. 3235 Prairie Ave. Boulder, CO 80301 www.boulderamp.
TABLE OF CONTENTS GETTING STARTED Placement of the 1008 Phono Preamplifier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 Connecting to the Mains Outlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2 Connecting to a Turntable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-3 Phono Cables Diagram. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EQUALIZATION Equalization Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-1 RIAA Reproduce Curve. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2 FFRR Reproduce Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3 EMI Reproduce Curve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GETTING STARTED PLACEMENT OF THE 1008 PHONO PREAMPLIFIER Your Boulder 1008 Preamplifier is designed to reduce interference from external magnetic and radio fields (RF). While placement is not critical, known magnetic fields should be avoided. Power transformers in other pieces of nearby equipment should be kept away by 1 foot or more. Because the preamplifier is heavy, a solid, stable surface should be used. The 1008 will generate some heat, so it should be allowed to have good air circulation.
r CONNECTING TO THE MAINS OUTLET Your 1008 Phono Preamplifier is supplied with a mains cord suitable to the location where it was purchased. Make certain that the “O” is pushed on the rocker switch before connecting to your mains. Your 1008 has been configured for the voltage suited to your location. Exact voltage and frequency specifications are located on the rear panel, right of the AC mains connector.
CONNECTING TO A TURNTABLE RIGHT INPUT #1 1-3 CHASSIS LEFT GROUND INPUT #1 TERMINALS Balanced inputs are provided for connecting up to two turntables to the 1008. To avoid hum pickup in the cabling, it is important to follow these instructions. Do not connect pin 1 (chassis/ ground) to either pin 2 or 3 at any point in the cable, turntable chassis, or tonearm. Pins 2 and 3 must only connect directly to the cartridge pins. This can be accomplished by several wiring schemes shown on the next page.
PHONO CABLES 1008 PHONO INPUT CARTRIDGE 2-POS INPUT 3-POS INPUT 1-POS INPUT TURNTABLE CHASSIS CHASSIS 1008 PHONO INPUT CARTRIDGE 2-POS INPUT 3-POS INPUT N.C.
CONNECTING TO A BALANCED INPUT PREAMPLIFIER For maximum sonic advantage, connect your 1008 Preamplifier’s balanced outputs to balanced inputs such as provided on all Boulder Preamplifiers. With the 1008’s low output impedance, distances of more than 50 meters between Phono Preamplifier and Line Preamplifier are practical. Connect each preamplifiers input to the connectors labeled “OUTPUT.
CONNECTING TO AN UNBALANCED INPUT PREAMPLIFIER A special cable is required to make this connection. This cable connects pin 1 to the shield and pin 2 to the center pin. It leaves the output pin 3 unconnected. Connecting the unused output pin (usually pin 3) to ground will cause excessive ground currents and degrade performance. Use an ohmmeter or continuity checker to determine how a cable is wired.
CARTRIDGE SET UP PERSONALITY CARD Each 1008 input has two slots for personality cards, one for left, and one for right channels. The cards serve two functions– a switch to set the electronics for the type of cartridge used at that input, and places to solder the custom load termination resistor and capacitor. The 1008 is shipped with all 4 cards installed in the rear panel. The cards are set to MC, and have a load resistor installed to set the input impedance to 100Ω.
MOVING COIL OR MOVING MAGNET SELECTION Set the switch to either Moving Coil (MC) or Moving Magnet (MM) depending on your type of cartridge. In the MC position, the maximum input resistance is 1,000Ω without additional components installed on the card. All four of the cards are shipped with a resistor to bring the impedance down to 100Ω, which is recommended for MC. Also in the MC position, an additional low noise, 26 dB gain stage is inserted at the input.
CARTRIDGE LOADING – RESISTIVE R1 2-3 For MC cartridges, the maximum resistive load is 1,000Ω. This is the value when there is no resistor added to the Personality Card. This value may be lowered by adding a resistor (as shown) at R1 whose value is calculated by the following: R1 = 1/(1/RDESIRED – .001) Some typical values are: Desired R (Ω) R1 (Ω) 50 52.3 100 110 200 249 500 1,000 For MM cartridges, the maximum resistive load is 47kΩ.
CARTRIDGE LOADING – CAPACITIVE CONNECT CAPACITOR FROM ONE LEFT HOLE TO ONE RIGHT HOLE 2-4 The 1008 Phono Preamplifier inputs have only “parasitic” capacitance of less than 50 pF directly across the cartridge inputs. If desired, additional capacitance can be added on the personality card at C1. The capacitor chosen should be 50 pF less than the desired value. Solder holes are provided for two different size capacitors. There are two pairs of holes as shown, two at left and two at right.
OPERATION POWERING UP With all your connections made, you are ready to listen to your Boulder 1008 Phono Preamplifier. Push on the “I” of the rocker switch on the rear panel of the 1008. No indication on the front panel will be shown. Press the STANDBY pushbutton on the front of the 1008. The STANDBY indicator will be amber. The MUTE indicator will be red and the output will be muted for the first 35 seconds to allow for circuit warm up.
INPUT SELECTION The Boulder 1008 Phono Preamplifier provides inputs for 2 cartridges. These can be from one or more turntables. Only one of these inputs can be used at a time. Select an input by pressing one of the pushbuttons labeled “INPUT 1” and “INPUT 2”. The 1008 will immediately mute the outputs and the MUTE indicator will be red for 3 seconds. After that time, the output will be unmuted and the MUTE indicator will be off.
EQUALIZATION The Boulder 1008 Phono Preamplifier provides the standard RIAA record equalization curve, along with the EMI, Columbia, and FFRR curves. See the Equalization section for more details. Select the RIAA equalization curve by pressing the pushbutton labeled RIAA. All three remaining curves may be selected by using the pushbutton labeled ALT EQ. Various alternate EQs are selected by repeatedly pushing “ALT EQ” until the desired LED is red.
LOW CUT FILTER The Boulder 1008 Phono Preamplifier uses a 3 pole (18 dB/octave) low cut filter which is -3db at 10 Hz. Because this filter is fairly steep, its effect is virtually negligible in the audio band. It is recommended that it be kept turned on in order to avoid excessive woofer travel caused by imperfect records. Select the low cut filter by pressing the pushbutton labeled LOW CUT. The indicator will then be amber. To completely turn off the filter, again press the pushbutton labeled LOW CUT.
MUTE The Boulder 1008 Phono Preamplifier provides an output mute feature which is turned on by two different methods. First, the outputs are muted for 35 seconds when the 1008 is first turned on. The 1008 is also muted for 3 seconds when an input or equalization pushbutton is pressed. The MUTE indicator will be red. Second, the outputs may be muted at any time for your convenience by simply pressing the MUTE pushbutton. the MUTE indicator will be red. To unmute, press the MUTE pushbutton again.
EQUALIZATION EQUALIZATION CURVES The Boulder 1008 Phono Preamplifier uses one of four equalization curves selected by the front panel pushbuttons labeled RIAA and ALT EQ. The 1008 is shipped with four standard EQ options: RIAA, FFRR, EMI, and Colombia. The following pages show the four equalization curves. All graphs are referenced to 0 dB at 1 kHz.
RIAA REPRODUCE EQUALIZATION REF 0 DB AT 1 KHZ 4-2 EQUALIZATION
FFRR REPRODUCE EQUALIZATION REF 0 DB AT 1 KHZ 4-3 EQUALIZATION
EMI REPRODUCE EQUALIZATION REF 0 DB AT 1 KHZ 4-4 EQUALIZATION
COLUMBIA REPRODUCE EQUALIZATION REF 0 DB AT 1 KHZ 4-5 EQUALIZATION
USING A RECORDER CONNECTIONS A recording device may be connected to the Boulder 1008 Phono Preamplifier. You may use balanced or unbalanced connections for both input and outputs as previously described in the sections on connecting sources and power amplifiers. Either of the outputs may be connected to the input of your recording device.
1008 AUDIO BLOCK DIAGRAM 1 PHONO INPUTS CARTRIDGE LOADING ON PERSONALITY CARD 2 1K LOW NOISE 26 dB GAIN FOR MC 47K MM BYPASS RIAA EMI COL PLAYBACK GAIN AND EQUALIZATION FFRR 10 HZ / 3-POLE LOW CUT FILTER BYPASS BALANCED OUTPUT BUFFER MAIN OUTPUTS STEREO MONO 6-1 APPENDIX FROM / TO OTHER CHANNEL
BOULDER 1008 PHONO PREAMPLIFIER SPECIFICATIONS Inputs 2 Balanced, Converts to Unbalanced Input Impedance, Maximum MC: 1000 Ω; MM: 47kΩ 1kHz Gain, RIAA MC: 70, MM: 44 Noise (EIN), MC 98 nanovolts Flat, 20 Hz to 20kHz Outputs 2 Balanced, use as Main or Record Maximum Output Level 16 Vrms Distortion, THD 0.01% Frequency Response, 20 Hz to 20 kHz RIAA: ±0.10 dB Crosstalk, L to R or R to L >100 dB or better 20 Hz to 20kHz Output Impedance 100Ω Balanced Preamp Size, W X H X D 18.0 x 5.0 x 15.
SYMPTOM No power indication on 1008 TROUBLESHOOTING CAUSE Power switch is not in ON position Turn on power switch Home circuit breaker is tripped Reset circuit breaker 1008 is not plugged in Low AC line voltage Power supply fuse blown Amber power indication on 1008, but no sound is heard Defective 1008 1008 is muted, MUTE indication is Amber No signal from turntable No signal out to preamplifier Hum through loudspeakers 6-3 APPENDIX REMEDY 1008 is faulty Connect to an AC outlet Have AC line c
SYMPTOM One channel is louder than the other TROUBLESHOOTING CAUSE MM/MC switch is not set the same on both Set MM/MC switches on channels personality cards to the same setting Cartridge loading is not equal Tonality or frequency response is incorrect Wrong equalization setting is selected Will not come out of Mute 6-4 APPENDIX REMEDY 1008 has not been stabilized after turn-on Check cartridge loads on personality cards Press ALTERNATE EQ button to select proper EQ setting Wait 35 seconds for 1008
NOTES Serial Number ________ 6-5 APPENDIX
