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SOLD Raven Labs PHA-1 Headphone Amp

Discussion in 'For Sale: Parts, Strings, and Accessories' started by Dan Knowlton, Jul 9, 2016.

  1. Dan Knowlton

    Dan Knowlton Sometimes you're the dog, sometimes the tree Gold Supporting Member

    Aug 12, 2002
    Palm Coast, FL
    Rare Raven Labs PHA-1 in excellent condition - just not using it as much as I thought I would. Includes the power supply but you can also run it off of two 9v batteries.

    Price is firm and includes ground shipping ONLY in the USA.

    I've pasted in info about the unit below the pictures.


    The PHA-1 is a professional unit that can be used as a headphone practice amp, versatile preamp, or to create your own mix in the studio. The PHA-1 will allow up to two players to plug in and practice together while monitoring their sound via the dual stereo headphone jacks.

    Using the patch chord provided, a stereo source (such as a portable CD player or cassette) can be blended into the overall sound. The left and right mix volumes adjust the levels of the external source, providing the ultimate environment for silent rehearsing, solo or with a fellow musician. Make sure you are in key by hooking up a tuner to the Auxiliary send. The sound of your instrument can be tailored using the 3 band EQ.

    Immediately noticable will be the sound quality, dynamic range and lack of annoying hiss. The PHA-1 will faithfully reproduce anything from a 5 string bass to the variety of sounds from a synthesizer.

    Are you done practicing and ready for the gig? The PHA-1 makes the ideal buffer between your instrument and amp. The high input impedance assures that ALL of you instruments tonal characteristics reach your audience. As well, the PHA-1 will provide additional gain and tone adjustments. The Auxiliary send and Stereo mix inputs can now act as a side chain effects loop. Being on a "side chain" insures the integrity of the natural sound of your instrument, while lowering the overall noise created by your effects unit. Use the Line Out to send the signal to your amplifier.

    The PHA-1 is powered by a pair of 9 volt batteries. Battery installation is easy using the battery compartment on the outside of the chassis. No "unassembly" is required. Battery life will be around 50 hours.

    Each unit comes with a 3 year guarantee against parts and workmanship.
    Front Panel Features
    High Gain Input
    Low Gain Input
    Volume Control
    Bass EQ Control
    Midrange EQ Control
    Treble EQ Control
    Stereo Left and Right Mix controls
    On/Off Power Switch
    Rear Panel Features
    p1rp.jpg p2rp.jpg
    Two Stereo Headphone Outputs
    Mono Line Out jack
    Auxiliary Send Output
    Stereo/Mono Mix input jack
    Stereo/Mono Mix In selector switch
    Dual 9 volt battery holder
    A/C Adaptor (Optional - not pictured)
    *All measurements taken with fresh 9 volt batteries.

    Power source: Dual 9 volt batteries. Over 50 hours life expectancy under normal use.

    Frequency Response: -3dB from 30Hz to 60KHz

    Preamp/Line Out: 0.008% @ 1KHz, +4dB
    Headphone Amp: 0.06% @ 1KHz, +4dB @ 75 Ohms

    Noise: -85dB typical (Tone Controls in "flat" position)

    Maximum Gain: 7.5X (17.5dB)

    Maximum Input Level: 2 volts RMS

    Input Impedance:
    Hi & Lo Inputs: 3.9 Meg ohms
    Left and Right Mix In inputs: 20K ohms minimum

    Maximum Output:
    Preamp/Line Out only: 3.2 volts RMS
    Headphone Out, 75 Ohms Impedance: 2.2 volts RMS (65 milliwatts)

    Output Impedance: Line Out, Auxiliary Send: 100 ohms

    Hi and Lo Inputs Gain Difference: The Low input has 3.5dB less gain.

    Resistors: 1%, 1/4 watt. Capacitors: Mylar (German Wima)

    Chassis: Steel, powder coated.

    Dimensions: 6.7" W x 1.75"H x 6"D

    Weight: 2 lbs., 3 oz.

    Raven Labs PHA-1 Owner's Manual

    The Professional Instrument Preamp/Headphone Amp from Raven Labs offers the musician a personal practice amplifier and preamp with sonic qualities and features that we feel are the finest and most useful in the marketplace. The precision electronics are powered by two nine-volt batteries in a +/- configuration and are housed in a black texture powder coated chassis. Only the very best components are used, including mylar capacitors, 1% resistors, Beldon cable, dual wiping IC sockets, and a double sided plated through circuit board. Entirely hand made in California.

    To get the most enjoyment out of your unit, please read the entire owners manual before operating. Thanks so much for putting your faith in our products.

    Front Panel Features

    Two 1/4" jacks are provided and will accept a variety of both active and passive instruments. The 4 Meg Ohm input impedance insures that ALL the information your instrument has to offer gets heard. Both inputs are independent and can be used simultaneously. The "HI" jack has 3 dB more gain than the "LO" input. If you are hearing distortion that can't be corrected by turning down the Volume or EQ section, try switching to the "LO" input jack.

    This function controls the level of both the HI and LO inputs. It does not affect the MIX input. It is located in the circuitry after the EQ section. If you hear some distortion and it is not corrected by turning down the volume, try adjusting the tone section or using the "LO" input jack. As well, check the batteries in the PHA-1 and your source (instrument).

    Bass, Midrange and Treble controls are provided for tailoring the sound to your liking. They affect only the source at the input jacks and not the Mix Input. Each control can provide up to +/- 12 dB of cut or boost. Flat (no boost or cut) position is when the knob indicator line points to the "0" setting on the front panel.

    The Bass control is centered around 80Hz, Mid Range at 800Hz, and Treble at 2KHz. The bandwidths of each control are different and chosen for their musical integrity.

    The EQ can be fun to experiment with while playing along with pre-recorded music. Use the Bass to add a solid foundation, or the Mid to bring out your instrument in the mix, and the Treble to add a certain sibilance overall. What may work for an overall sound with other instruments may be completely different from listening to just yourself individually.

    MIX L and MIX R
    These adjust the level in your headphones of the signal coming from the "Mix In" input on the back panel. Both controls must be turned up regardless if the mix signal is stereo or mono for sound to be heard in both sides. They do not affect the signal coming from the input jacks.

    Note: If you are using the PHA-1 as a preamp, the "Aux Send" and "Mix In" can act as a side chain mono effects loop. Use the MIX L to adjust the level of the effects unit present at the LINE OUT jack.When using headphones, the Aux Send and Mix In can function as a stereo effects loop. See Rear Panel Features for more information.

    Pushing the power switch in turns on your product as indicated by the red LED lighting. Be sure and turn off the PHA-1 when not in use to extend battery life.

    Rear Panel Features

    Lifting up and out removes the drawers that hold the two 9 volt batteries that operate your unit. Be sure and observe correct polarity during installation. If your PHA-1 does not turn on after installation, immediately turn the power switch off and recheck polarity. Always use quality batteries. Battery life is expected at 50+ hours.

    Will accept either a stereo or mono signal. The level in the headphones is adjusted by the Mix L and R controls on the front panel. The level at the Line Out is controlled by the Mix L only. Input impedance is 20K ohms minimum.

    To play along with pre-recorded music: Using the stereo patch cord provided, plug the mini phone plug end in the "line out" or "headphone out" of your source (CD player, cassette deck, etc.) and the 1/4" (larger) end in the Mix In jack; Adjust the Stereo/Mono switch accordingly; Use the Mix L and Mix R controls on the front panel to adjust the level in the headphones.

    Use the Volume to adjust the level of your instrument with the pre-recorded music. If you are having trouble, make sure all units are on, connections are correct, and volumes are up (i.e. headphone level on CD or cassette when using headphones out).

    Located before the EQ section, the Aux send can be used to hook up a tuner, etc., or, when using an effect, run a patch cord to the input of your effects unit. The output of the effects goes to the Mix In jack. Only the signal at the input jacks is present at the Aux jack.

    Note: If you are using the PHA-1 as a preamp, and using an effects unit, use the Mix L to adjust the level of your effects present in the Line Out jack.

    When using the PHA-1 as a preamp, use the Line Out to send a mono signal to the input of your amplifier. The level is adjusted by the Volume control on the front panel. See above for more information when using an effects unit.

    Use a high quality pair of headphones having an impedance of 16 ohms or greater and can handle at least 50 milliwatts (.050 watts). The best match for the PHA-1 is around 75 ohms. When using TWO pair of headphones, they cannot be less than 35 ohms apiece and should have an equal impedance. When using two unmatched pair of headphones, the lower impedance will sound louder. Remember, the headphones are the last link in the chain and
    can make or break the sound you're looking for.
    Fred312b likes this.
  2. drumsnbass

    drumsnbass Bassic User

    Dec 13, 2004
    Phoenix AZ area
    These are incredibly nice! I have one and every time I think if parting with it I just can't do it.

    The power supply is rarer than rare earth metals. Nice combo!
  3. LowBSix

    LowBSix Supporting Member

    Mar 25, 2008
    818 ~ 805 ~ L.A.
    Endorsing Artist: GHS Strings
    Is this available?
  4. Dan Knowlton

    Dan Knowlton Sometimes you're the dog, sometimes the tree Gold Supporting Member

    Aug 12, 2002
    Palm Coast, FL
    Sorry for the delayed response. I'm out of town for a few more days but, yes, it is still available

  5. Type-55

    Type-55 Supporting Member

    Jul 20, 2000
    I had one of these for years. They are excellent.
  6. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

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