Sonic Studios™ DSM Mic Preamplifier

Model PA-3SX Owners Manual

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Model PA-3SX is precision designed to solely power and amplify DSM-1S/6S series microphones for optimum performance using small portable recorder LINE inputs.

The PA-3SX is very compact, low noise/distortion, long running, high quality mic - to - line level preamplifier using the most precision surface mount and through-hole components available.†

Belt clip and Velcro adhesive patch facilitates attachment to shirt pocket size and larger portable recorders.

PA-3SX-U version has miniXLR input/output professional locking connectors fitting DSM mics with optional miniXLR plug, and output patch adapters fitting any style of deck input jacks.

User settings are 1/2/3 toggle switch gain choice, and a slide ON/OFF power switch.† A single red LED shows power on, low battery, and near clip indications.


Expect exceptional longest running time of~ 500 hours using two AA Energizer brand L91 photo lithium cells.

(Sony OXYride AA shown above = ~200 hrs)


1) The PA-3SX preamplifiers output is connected to a recorder's line input.

Optional adapters from Sonic Studios connect the preamp's output to various line input connector types and/or provide custom extension cable lengths to 15í

    2) 3.5mm or miniXLR MIC- INPUT/LINE-OUTPUT connectors on in-line short-cord length.  

3) POWER ON-OFF slide-switch is located on the right side panel.


4) 1-2-3-position gain toggle switch is located on the front panel.


5) A single red LED indicator shows:

  • power ON (very dim) continuous display
  • low battery (very bright) steady on
  • near clip very bright flashes

The PA-3SX requires 2 AA battery cells for 100 to over 500 hours running time depending on cell type.


Shipped ready to use with long life Energizer L91 lithium cells installed.


Photo Lithium cells type are good for up to 10 years standby (power OFF storage), or 500+ hours of power ON recording in temperature extremes of -40F to 125F ambients.


When the red LED glows BRIGHT steady, the batteries need replacing.

(NOTE: Dim steady glow means only power is ON)



Remove the screw from the top (clip side) cover with supplied Phillips screwdriver.

Slide the cover backwards to access the battery compartment.

(as shown at left)


Push (using fingertip) against each (+) battery terminal, slightly compressing the (-) NEG. contact spring.† Then lift up the (+) cell end to remove as shown at right.


Suggest wiping the fresh battery ends with a clean cloth to remove lint/oils.


Replace with two fresh (L91 type is best) AA cells by inserting (-) negative battery terminal first against the spring, while inserting the cell fully into each holder.


TIP: After replacing, check that battery holder spring contacts are centered on cellís - end. To insure good contact, give each cell a rotational spin in the holder. Then replace sliding cover and screw secured only snug, not over-tight.


Set the deck for analog LINE input recording. Turn ON preamplifier power after connecting to the recorderís LINE input. (NOTE: Newer models now show dim RED LED as power ON indication)


Select highest preamplifier GAIN setting NOT showing bright RED 'near' CLIP LED flash indications. Remember to monitor both preamp near clip LED, and deck's VU for best chance of avoiding clipping distortions by turning down gain when necessary.


After setting preamplifier gain, then adjust deck's recording level for VU average peaks at no more than -12 dB VU for 24 bit depth mode recording, or no more than -6dB absolute peak if recording at 16 bit depth mode. Conservative VU levels allows for headroom (overload margin) for louder than expected sounds, and using 24 bit depth mode (when available) preserves a much higher resolution of very low VU level recorded sounds.

    INPUT: ~2K Ohm impedance with 1.6 Volt mic powering specific for DSM-1S/6S stereo mic models. Preamp also works with other condenser/dynamic low output impedance self-powered type mics.  
    OUTPUT: +2.2 dBv (~1Vrms), 50 W drives full output into to >250 W load.  
    -3 dB BANDWIDTH: 10-to-75,000 cycles #1 lowest gain setting (20 dB), 10-55,000 cycles #2/#3 (28/36 dB Gain) medium/high settings  
    NOISE:<-106 dBu = <4mv (unweighted) 10-50,000 cycles  
    CHANNEL SEPARATION: > 110 dB 10-30,000 cycles  
    CHANNEL GAIN MATCH: ~0.03 dB precision preserves stereo-surround image  
    BATTERY POWER: (2) AA cells, Supplied with L91 type (Energizer photo lithium).  
    RUN TIME:500+ hours (two L91 MAIN cells), ~100+ with regular Alkaline. NOTE: DO NOT USE RECHARGEABLE TYPES as 1.25 volt cell voltage is too low.  
    LOW BATTERY: 2.70 volts = ~1.35Volts/cell; BRIGHT LED continuous indication  
    NEAR CLIP: -2.5 dBv below maximum clip distorted output; BRIGHT LED flash indication  
    Full 2 year limited warranty for repair/replacement. Shipping cost not included.  
Sonic Studios
1311 Sunny Court
Sutherlin, OR 97479-9496 USA
Phone (541) 459-8839
USA Free: 1-877-347-6642
© 2008 Sonic Studios ™ All rights reserved; VERSION DATE 11/27/2008


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