Fishman_Prefix_Pro_Blend_Manual 电路图.pdf

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1、TM BlendPRO ACOUSTIC GUITAR SYSTEM US E RSGU I D E WARNING! WE STRONGLY RECOMMEND THAT YOU FAMILIARIZE YOURSELF WITH THE PREAMP CONTROLS BEFORE YOU ATTEMPT TO PERFORM WITH THE ONBOARD BLENDER. FAILURE TO DO SO COULD RESULT IN WAVES OF EAR-SPLITTING FEEDBACK AT HIGH LEVELS. (see Quick Start on page 3

2、.) Congratulations! With your new Fishman PrefixProBlend we are pleased to offer a total onboard amplification system in a very small and unobtrusive package. This is a simple yet sophisticated system, so please take a few minutes to familiarize yourself with the control lay- out and go over the Qui

3、ck Start instructions on the next page. If you have any questions please contact our Customer Service Department at 978.988.9665 or The PrefixProBlend is an acoustic guitar system that combines the sounds from a Fishman Acoustic Matrix pickup and a miniature electret condenser microphone. The microp

4、hone, shock-mounted on the underside of the preamp chassis, captures the elusive natural ambi- ence and resonance of the guitars sound chamber. The Acoustic Matrix pickup delivers a clear, articulate sound with emphasis on string definition and attack. When combined, the two signals produce a powerf

5、ul and cohesive acoustic guitar tone that is much greater than the sound of either microphone or pickup alone. Downsized to fit even the thinnest of guitars, the second generation PrefixProBlend preamp occupies 1/3 less surface area on the side of a guitar than our standard Prefix series. The preamp

6、 module incorporates a space saving flip-top battery compartment for easy access. Levels are set by the master VOLUME and BLEND controls. BASS a Notch Filter, a Phase Switch, and a Semi-parametric Contour Control. Follow these steps to achieve a strong, feedback-free sound. 1.Before you plug in, set

7、 all controls as follows: NOTCH and VOLUME fully counter-clockwise All sliders at their center positions BLEND slider at MIC position 2.Plug in the instrument first (with 9V alkaline battery installed), then plug in to your amplifier, with the tone controls on the amp set as flat as possible. 3.Slow

8、ly increase the VOLUME until the guitar and speaker are approximately the same level. Play the open E string and flip the PHASE switch. Leave the switch in the position that sounds the deepest and clearest.(for more on phase, see page 8) 4.Slowly increase the volume until the instrument starts to ru

9、mble with low frequency feedback 5.Use the NOTCH FILTER to scoop out the lowest range of feedback, which usually starts at the open low E string and continues up to about the forth fret G# on the same string (often near two o clock). 6.Use the PHASE SWITCH to control the upper range of low frequency

10、 feedback, which usually starts at the fifth fret A on the low E string and continues up to about the twelfth fret E on the same string. Flip the PHASE SWITCH back and forth until you find the position that subdues this range of feedback. 7.Slowly increase the VOLUME again, until the microphone just

11、 starts to squeal. 8.Lower the CONTOUR Level all the way down. Slowly adjust the Contour FREQUENCY rotary control until the squealing feedback is eliminated. Raise the CONTOUR Level slider (if possible) to just below the threshold of feedback. 9.Gradually mix in the pickup signal by adjusting the BL

12、END slider. The pickup signal will add significant attack and definition to your sound. 10. Adjust the BASS and TREBLE controls as desired. Please note that these controls will affect pickup signal only. 11. Double check the PHASE switch position until you find the clearest, feedback free response.

13、12. Play your guitar as loud as you want. FI S H M A NPR E F I X SE R I E S 4 FUNCTIONS Battery Compartment Pull the small tab at the top of the Problend toward you. The body of the preamp will swing out, revealing the BATTERY COMPARTMENT. Install a fresh 9V alkaline battery. Microphone Trim Control

14、 A small circular potentiometer is located on the side of the preamp that faces the back of the guitar. This control can be accessed by opening the battery compartment.Use this control to fine tune the microphone volume, in relation to the pickup volume.To adjust the microphone trim control, set the

15、 BLEND slider to the center position and, with a slotted jewelers screwdriver, turn the potentiometer until both the microphone and pickup levels are balanced to your taste. POWER The PrefixProBlend has no ON/OFF switch. To turn on the power, plug an instrument cable into the endpin jack. To conserv

16、e the battery, remove the instrument cable from the endpin jack when the unit is not being used.It is a good idea turn down your amp or mixers input before you plug into this input. Doing so will protect your speakers (and your ears) from loud pops and thumps. Clip / Battery Low LED This light has t

17、hree distinct functions: 1. Power Up Indicator The Clip/Batt Low LED will flash momentarily when you first turn on the preamp. Some people ask us why this light doesnt stay on, like a conventional pilot light. We feel a steadily lit LED devours too many precious hours of battery life. We prefer inst

18、ead to conserve the battery with a quick flash of the LED to indicate that the preamp is powered up. 2. Clip Indicator If the LED flashes while you are playing, you are driving the preamp into distortion. Lower the Treble and/or Bass slider until the flashing stops. This indicator may also flash as

19、you approach the end of the batterys useful life. 3. Low Battery Warning When the Clip/Low Batt LED lights steadily, it is time to change the battery. Volume Affects both microphone and pickup levels. Set this as high as possible (without distorting your amp or mixer) for the cleanest signal. RadioF

20、ans.CN 收音机爱 好者资料库 PR E F I X PR OBL E N D Notch and Phase These controls work hand in hand to eliminate low frequency feedback. When you set them properly, you can play your instrument as loud as you like, without feedback. For best results, tune the Notch filter first. Notch Use the Notch to scoop

21、out the lowest range of feedback, which usually starts at the open low E string and continues up to about the forth fret G# on the same string. This cavity resonance feedback can usually be eliminated by setting the Notch control between 12:00 and 2:00 on the dial. You may need to initially coax out

22、 low frequency feedback by raising your volume, flipping the phase switch and moving closer to your speakers. Note that in the fully counter-clockwise position, the Notch is effectively off. Phase Switch Use the phase switch to control the upper range of low frequency feedback, sometimes call top re

23、sonance.This feedback usually starts at the fifth fret A on the low E string and continues up to about the twelfth fret E on the same string. Flip the Phase switch back and forth until you find the position that subdues this range of feedback. Note: If, after setting the phase switch, you move your

24、position a few feet, be prepared to flip the switch again to keep feedback at bay. Bass A boost/cut shelving tone control. This control affects the pickup signal only. In the center position the bass control does not affect the circuit. Contour EQ With this you can boost or cut a wide range of frequ

25、encies from gutsy low midrange (250 Hz) to squeaky-clean highs (10 kHz). Contour affects both the pickup and microphone signals. The CONTOUR level slider controls the amount of boost or cut applied to the selected Contour FREQUENCY. The center detent yields a flat response. The Contour FREQUENCY sli

26、der determines the frequency band that is boosted or cut by the CONTOUR Level control. The frequency is variable between 250 Hz and 10 kHz. Treble This is a boost/cut shelving tone control. Treble affects the pickup signal only. In the center position the treble control does not affect the circuit.

27、Blend balances the microphone and pickup signals. This control can be used as a feedback escape hatch if you ever need to instantly shut off the microphone during a performance. 5 SUGGESTED EQ SETTINGS ANTI-FEEDBACK Refer to page 3. BRILLIANCE If you play through an electric guitar amplifier, or use

28、 dead strings on the instrument, you can brighten up your sound by setting the Contour FREQUENCY slider at 4:00 and raising the contour LEVEL to taste. If you plan to play at high stage volume levels, dial in more pickup than microphone with the Blend control to avoid feedback. FI S H M A NPR E F I

29、X SE R I E S 6 RadioFans.CN 收音机爱 好者资料库 PR E F I X PR OBL E N D 7 MID CUT You can scoop out harsh midrange by set- ting the FREQUENCY slider AROUND 12:00 with the CONTOUR Level cut to taste below the center detent. Often the desired mid-cut will fall into the same frequency range as potential microph

30、one feedback. You can also cut midrange (pickup only) by boosting the BASS and TREBLE sliders to realize an implied mid-cut at 800 Hz. FINGERSTYLE This setting will add fullness to the bass and definition to the treble. FI S H M A NPR E F I X SE R I E S 8 WHAT IS PHASE? Phase is the relationship bet

31、ween two signals or sound waves originating from the same instrument. For our purposes, phase relationships are expressed as being either in phase or out of phase.In phase tends to enhance, while out of phase tends to suppress the natural characteristics and acoustic tendencies of an instrument.A si

32、mple way to determine the quality of phase (in or out) of two sounds is to compare phase switch settings at low volumes. IN PHASE In phase is when the wave forms of two sounds originating from the same instrument are similarly aligned in time. Similar phase is like looking at yourself in a mirror: y

33、our reflection directly follows your movement. OUT OF PHASE Out of phase is when the wave forms of two sounds originating from the same instrument are aligned such that the upper peak of one wave occurs at the same moment in time as the lower peak of the other.Out of phase is like looking at yoursel

34、f in a live video monitor; the image you see is similar, but the perspective is shifted. When you move to the right, the image appears to move to your left. UPPER PEAK LOWER PEAK PR E F I X PR OBL E N D 9 WHY DO I NEED A PHASE SWITCH ? The phase switch is useful for two reasons: 1. Due to the intera

35、ctive 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 compensate for any

36、unintentional differences that might occur between instrument and sound system. APPLICATIONS In any situation where the miced instrument faces a loudspeaker, there will be an interactive phase relationship between the two. This usually occurs with stage amps, side fill and floor monitors at close di

37、stances. LOW VOLUME AMPLIFICATION At low volumes, when a miced 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 out to som

38、e extent.The resulting sound is somewhat unnatural and unbalanced compared to in phase. HIGH VOLUME LEVELS At high volume levels, when a miced instrument and speaker are in phase, the sound pressure from the speaker will excite the instruments sound chamber, creating a feedback loop at the instrumen

39、ts lowest octave.This cavity resonance feedback can be dealt with by putting the miced 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 miced instrument and speaker out of phase with each other, cance

40、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 . FI S H M A NPR E F I X SE R I E S 10 Continued from Page 9 Here

41、s why: A typical guitar has a cavity resonance of about 100 Hz. This is the frequency that generally feeds back when a miced 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

42、 1/2 feet. 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 FI

43、LTER TO REDUCE FEEDBACK Notching out instrument cavity resonance will eliminate the low frequency feedback 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 instrumen

44、t/speaker can remain in phase, maintaining a more natural and balanced response at lower volume levels. DISTANCE:5 7 PHASE INVERTED 180PHASE INVERTED 180 11 417 22 7 The PHASE switch on the ONBOARD BLENDER in effect electronically moves your instruments position relative to the speaker by inverting

45、the phase 180 every time you flip it. SPECIFICATIONS Nominal Input Level:-20 dBV Input Overload:(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

46、nominal -20 dBV input) Current Drain:Less than 4 mA Power Supply:9V Alkaline battery (estimated 140 hours continuous use with low battery indicator at 6.5V) Notch Filter Range:50Hz - 900 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 k

47、Hz Contour Control Range: 12dB (adjustable from 250 Hz to 10 kHz) Q = 0.5 All specifications subject to change without notice. PR E F I X PR OBL E N D TM BlendPRO ACOUSTIC GUITAR SYSTEM 11 PICKUP ONLY INSTALLATION BY A QUALIFIED PROFESSIONAL REPAIRMAN IS STRONGLY RECOMMENDED. FISHMAN TRANSDUCERS WIL

48、L NOT BE RESPONSIBLE FOR ANY DAMAGES THAT MAY RESULT FROM IMPROPER INSTALLATION. The FISHMAN PrefixProBlend 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 o

49、ption of replacement or refund in the event that FISHMAN is unable to make 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 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 othe