Fishman_Prefix_Plus_Manual 电路图.pdf

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1、USERS GUIDE RadioFans.CN 收音机爱 好者资料库 This fine instrument is equipped with a FISHMAN PREFIX PLUS ACOUSTIC GUITAR SYSTEM. Please read these instructions care- fully. If you have any questions or problems, please call our CUS- TOMER SERVICE LINE at (978) 988-9665. The PREFIX PLUS is an instrument-mount

2、ed pickup / preamp sys- tem that offers total control of your amplified guitar sound. THE PICKUP The PREFIX PLUS ACOUSTIC GUITAR SYSTEM includes the FISH- MAN ACOUSTIC MATRIX pickup; made with a unique co- polymer sensing material available exclusively from Fishman. This technology is not available

3、from any other manufacturer. The sensing material exhibits a sensitivity and dynamic range that far surpasses all other known sensing materials. The ACOUSTIC MATRIX transducer is a fully EMI shielded, multi-layer sandwich of co-polymer strips that run the length of the pickup. This design allows the

4、 pickup to sense the motion of the entire saddle length, providing superb string to string balance, as well as sensitivity to both the strings and top of the instrument. THE PREAMP The PREFIX PLUS preamp module incorporates a unique flip-top battery compartment for easy access. A variable NOTCH filt

5、er, shelv- ing BASS the image you see is similar, but the per- spective is shifted. When you move to the right, the image appears to move to your left. Continued . ONBOARD ACOUSTIC GUITAR SYSTEM 9 PHASE, Continued from Page 8 WHAT IS THE PHASE SWITCH FOR? The phase switch is useful for two reasons:

6、1. Due to the interactive and changing nature of phase, acoustic amplification depends on maintaining optimum phase relationships between amplified instruments, sound systems and venues. 2. Since an industry standard for polarity has not been established for all sound equipment, the phase switch can

7、 compensate for any unintentional differences that might occur between instrument and sound system. APPLICATIONS In any situation where the instrument faces a loudspeaker, there will be an inter- active phase relationship between the two. This usually occurs with stage amps, side fill and floor moni

8、tors at close distances. LOW VOLUME AMPLIFICATION At low volumes, when an instrument and speaker are at similar levels and are in phase, the sound is full and solid, with the lower frequencies emphasized. When a miced instrument and speaker are out of phase at low levels, the bass frequencies cancel

9、 out to some extent. The resulting sound is somewhat unnat- ural and unbalanced compared to in phase. HIGH VOLUME LEVELS At high volume levels, when an instrument and speaker are in phase, the sound pressure from the speaker will excite the instruments sound chamber, creating a feedback loop at the

10、instruments lowest octave. This cavity resonance feed- back can be dealt with by putting the instrument and speaker out of phase or by adding equalization. A. USING THE PHASE SWITCH TO REDUCE FEEDBACK. Inverting the PHASE switch will put the instrument and speaker out of phase with each other, cance

11、lling the low frequency feedback. If you move from your position on stage more than a few feet, you may have to invert the PHASE switch again to maintain an out of phase relationship between the miced instrument and speaker. Continued . FISHMAN PREFIX PLUS 10 PHASE, Continued from Page 9 Heres why:

12、A typical guitar has a cavity resonance of about 100 Hz. This is the frequency that generally feeds back when the guitar and speaker are in phase. 100 Hz has a wavelength of about 11 feet. Phase inverts 180 for every 1/2 a frequencys wavelength. In this case, 1/2 the wavelength is about 5 1/2 feet.

13、If you set your PHASE switch to eliminate cavity resonance (out of phase) and then move 5 1/2 feet towards or away from the speaker, you will effectively put the miced guitar/speaker relationship at 100 Hz back in phase;in the line of fire for low frequency feedback. B. USING THE NOTCH FILTER TO RED

14、UCE FEEDBACK Notching out instrument cavity resonance will eliminate the low frequency feed- back problem completely. The advantages to using notching equalization are: The physical distance from the speaker will no longer be a factor for potential low frequency feedback. The miced instrument/speake

15、r can remain in phase, maintaining a more nat- ural and balanced response. The PHASE switch on the ONBOARD BLENDER in effect electronically moves your instruments position relative to the speaker by inverting the phase 180 every time you flip it. SPECIFICATIONS Nominal Input Level:-20 dBV Input Over

16、load:(20 Hz - 20 kHz)-2 dBV Input Impedance:20 M Ohms Output Impedance:Less than 3.5 k Ohms Nominal Output Level:-12 dBV THD:Less than .04 %, -20 dBV input Signal to Noise Ratio:77 dB (A weighted referred to nominal -20 dBV input) Current Drain:Less than 3.5 mA Power Supply:9V Alkaline battery (esti

17、mated 160 hours continuous use with low battery indicator at 6.5V) Notch Filter Range:40Hz - 500 Hz (-15 dB) Bass Control Range: 12 dB at 60 Hz 3 dB at 350 Hz Treble Control Range: 12 dB at 10 kHz 3 dB at 2.4 kHz Contour Control Range: 12dB (adjustable from 250 Hz to 10 kHz) Q = 0.5 Brilliance Contr

18、ol Range: 9 dB at 10 kHz 3 dB Bandwidth 7 kHz All specifications subject to change without notice. ONBOARD ACOUSTIC GUITAR SYSTEM 11 INSTALLATION BY A QUALIFIED PROFESSIONAL REPAIRMAN IS STRONGLY RECOMMENDED. FISHMAN TRANSDUCERS WILL NOT BE RESPONSIBLE FOR ANY DAMAGES THAT MAY RESULT FROM IMPROPER I

19、NSTALLATION. The FISHMAN PREFIX PLUS ACOUSTIC GUITAR SYSTEM is warranted to function for a period of One (1) Year from the date of purchase. If the unit fails to function properly within the warranty period, free repair and the option of replacement or refund in the event that FISHMAN is unable to m

20、ake repair are FISHMANs only obligations. This warranty does not cover any consequential damages or damage to the unit due to misuse, accident, or neglect. FISHMAN retains the right to make such determination on the basis of factory inspection. Products returned to FISHMAN for repair or replacement

21、must be shipped in accordance with the Return Policy, as follows. This warranty remains valid only if repairs are performed by FISHMAN. This warranty gives you specific legal rights and you may also have other rights which may vary from state to state. RETURN POLICY To return products to FISHMAN TRA

22、NSDUCERS, you must follow these steps. 1. Call FISHMAN TRANSDUCERS at 978-988-9199 for a Return Authorization Number (“RAN”). 2. Enclose a copy of the original Bill of Sale as evidence of the date of purchase, with the product in its original packaging and a protective carton or mailer. 3. FISHMAN T

23、RANSDUCERS technicians will determine whether the item is covered by warranty or if it instead has been damaged by improper customer installation or other causes not related to defects in material or workmanship. 4. Warranty repairs or replacements will be sent automatically free of charge. 5. If FISHMAN TRANSDUCERS determines the item is not covered by warranty, we will notify you of the repair or replacement cost and wait for your authorization to proceed. FISHMAN TRANSDUCERS 340-D Fordham Road Wilmington MA 01887 USA Phone 978-988-9199 Fax 978-988-0770 009-087-003 3-98 LIMITED WARRANTY