HOW TO BUILD: Amplifier

1) For each SLOrk speaker, six discrete amplifiers are need (one for each speaker).

Each Sonic Impact 5065 Generation 2 T-Amp amplifier has two channels (stereo),

so get three of them, and follow the instructions below for each.


2) Unpack the amplifier box, get the main amplifier and remember to save the DC power supply. 

This power supply will eventually be used to power the entire speaker.  Set aside remaining contents.


3) Unscrew the enclosure.  There are five screws: the four corners and one in the center typically

underneath the QC PASS sticker.


4) To open the enclosure, push in the volume knob and pull up apart.  Don't be too afraid to pull

too hard.  The front white face plate is glued to the gray base of the enclosure and requires some

muscle to unstick.  Unplug the headphone cable from the top of the case and set the top aside.


5) Take a pair of wire cutters and clip the black and red wires that are attached to the battery

casing.  Do not cut the black and red speaker inputs, just the battery connections so the amp

board can easily be removed from the enclosure.


6) Cut off the headphone jack cabling as close as possible to the amp board.  Some additional soldering

will be required because of this, but in the end it reduce the extraneous wiring.


7) From here, unplug the volume knob cable from the main amplifier circuit board (green).


8) Unscrew the amp circuit board from the enclosure (4 screws) and carefully remove the

amp.  Careful of the speaker inputs when pulling away from the thin black backing of the amp

enclosure. At this point, the amplifier should look something similar to the pictures below.


9) The battery black and red wire can now be cut as close as possible to the circuit board


10) The amplifier will be used with a fixed volume level, so the volume control cabling can now be cut

off as well. Note that you can reattach the volume potentiometer from the amp enclosure if you would

like to use it an alternate speaker design, however, for simplicity and to save space we replace the

variable control with fixed resistors (see below).  At this point the amplifier should look something

like the image below.


11) Because the headphone jack was detached, minor soldering is necessary

to fix the modification.  The audio signal of the amp previously went through

headphone jack cabling.  When cut off, the audio signals became open circuits. 

We must force a short circuit and solder pin 1 to pin 3 and pin 2 to pin 4 with

solid core wire.

12) To fix the volume control, additional minor soldering is necessary. The red and

black wires within the volume control cable held the on/off signal for the amplifier.

This must be forced to always be on by a short circuit between pin 1 and pin 2. 

Additionally, two resistors must be soldered on to replace the potentiometer with a

fixed pair of resistors.  For the SLOrk speaker, two 10kΩ resistors were used to replace

the 50kΩ pot.  Match the red and black cable to determine the pin orientation.  Resistors

should be put between pin 3 to pin 7 and pin 6 to pin 5.  Note newer models of the

amplifiers, seem to have changed the order of the red and black wires, so differences in

schematics are possible.

10) Now, on the bottom side of the amp board,  soldered two 6'' pieces of solid wire to

the bottom of the DC power jack.  In the diagram, the soldered red wire corresponds to positive

voltage and the soldered black wire corresponds to ground.  Once three of the amps are complete,

the power supplies for all three will be connected together (red to red and black to black) and

finally connected to the DC power jack on the exterior of the speaker enclosure.


13) At this point, one of the three amplifiers is complete.  Repeat the previous assembly for two additional

amplifiers.  Once the speaker enclosure is ready, the three amplifiers will be attached to the speaker

base and be securely stacked on top of each other using the 3/8'' and 3/4'' Male-Female Aluminum Hex

Standoff Screws.  The final result should look similar to the image below.





Nicholas J. Bryan
Center for computer Research in music and acoustics (CCRMA)
Stanford university, California USA