Posts – Beat Shelter

Posted on July 11, 2018November 4, 2022 by fleshone — 2 Comments

Skiratcha Tonearm Install Guide

Skiratcha Tonearm Install Guide
-adds an m44-7 compliant tonearm with integrated phono preamp to the Numark PT01USB, and PT01-Scratch

Parts needed:
-Skiratcha Tonearm kit
-Philips Screw driver

notes:
-the Skiratcha Tonearm has an integrated RIAA phono preamp. Do not install an additional preamp.
-the spring counterweight adds the ideal weight for record playback. Add the optional black tension band (see step 41) to increase stylus weight, while scratching
-touch the Skiratcha chicken head to turn on/off the headshell lights
-use the integrated bass kill slide switch to turn on/off bass kill
-add platter bars for best bounce performance

-Before You Start: Test Your PT01
-Any defects in performance will likely still be present after upgrading the tonearm. Fix them first
-Make sure the power turns on and you see the red power light (next to the 33/45/78 rpm switch)
-Listen to a record using headphones connected directly to the PT01’s headphone jack
-Using headphones, make sure the left and right audio channels are both working
-Using headphones, listen closely for any audio hum or buzzing
-Using headphones, turn on the motor without playing a record
-Listen for any pops or hum, while the motor is turned on and off and while the motor is running

-Remove Existing Tonearm (part 1)
1. See tonearm removal guide. Keep the tonearm axle for the Skiratcha install.

-Open the PT01
2. Remove the 8 screws on the bottom of the PT01 (see pic_1_open_pt01)
3. On the PT01’s USB board, unplug the red and white audio connectors (see pic_2_USB_cables)
4. On the PT01’s power supply board, unplug the TE14 red/white power cable and the TE12 black ribbon cable (see pic_3_power_cables)

-Remove Existing Tonearm (part 2)
5. On the PT01’s main board, remove capacitors C8 and C18. The easiest way to do this is to clip the leads with wire cutters or fingernail clippers. Cut the capacitor legs flush with the main board, so they do not touch each other or other parts of the main board (see pic_4_remove_capacitors_and_wires)
6. On the PT01’s main board, remove the existing tonearm wires. Cut the existing tonearm wires from the “R IN”, “GND”, and “L IN” bars. Cut them as close to the bars as possible, so they do not touch each other (see pic_4_remove_capacitors_and_wires)

-Mount the Tonearm Clip
7. On the platter side of the PT01, mount the tonearm clip. Remove the paper backing from the clip’s adhesive, and press it onto the existing tonearm clip. Note the orientation of the clip’s step groove (see pic_5_clip_install)

-Mount the M44-7 Cartridge
8. Remove the stylus from the m44-7 cartridge. This will avoid damage to the needle during the tonearm install.
9. Connect the m44-7 to the tonearm wires (see pic_6_headshell_wires)
10. Mount the m44-7 onto the headshell using the included black screws, nuts, and hex key. The screw head should be on the top side of the tonearm, and the nut should be below the cartridge (see pic_7_mount_m447)

-Mount the Tonearm
11. Feed the Skiratcha tonearm wire through the spring clip using the included tweezers. Note that the flat part of the spring clip should face upwards towards the tonearm (see pic_8_spring_clip)
12. Feed the Skiratcha tonearm wire through the PT01’s tonearm base (see pic_9_base_wire)
13. Press fit the spring clip into the PT01’s tonearm base. Make sure to press the spring clip all the way down (see pic_10_spring_clip_installed)
14. Align the holes in the Skiratcha tonearm’s base with the PT01’s metal tonearm base. Remove the slack in the tonearm wire by gently tugging on the tonearm wire from inside the PT01.
15. Press the smooth end (not the knurled end) of the tonearm axle through the tonearm base, PT01 metal base, and spring clip (see pic_11_tonearm_axle)
16. Look through the hole on the opposite side of the tonearm to align the tonearm holes with the holes in the PT01 base, and press the knurled side of the tonearm axle into the tonearm (see pic_12_hole_alignment)
17. Press fit the neck of the Skiratcha tonearm into the tonearm clip to secure the tonearm (see pic_13_secure_tonearm)

-Connect Tonearm Wires to Tonearm Adapter Board (TAV2)
18. Close and lock the PT01’s lid onto the top half of the PT01. This will protect the tonearm, while we complete the install (see pic_14_close_lid)
19. Pick up the top half of the PT01 and place it on a table with the cover side down
20. Bend the Skiratcha tonearm wires into a pitchfork shape. The wire order should be black (GND), white (right), yellow (left), red (+). Make sure that the exposed wire ends are bent back onto the wires insulation. The adds strength to the wire, when connected to the green terminal block (see pic_15_wire_ends)
21. On the Tonearm Adapter board, use the supplied blue screw driver to loosen all 4 of the green terminal block screws (i.e., open all 4 terminal block holes)
22. Insert all 4 Skiratcha tonearm wires into the Tonearm Adapter board’s green terminal block at the same time. Make sure the wires are inserted all the way into the terminal block (see pic_16_terminal_block)
–Very important: note the wire orientation: black (GND), white (right), yellow (left), red (+)
23. Tighten all 4 terminal block screws

-Connect Tonearm Adapter Board (TAV2)
24. On the PT01 main board, unplug TE13 (see pic_17_TE13)
25. Connect the TE13 wire from step 24 to the “USB” header on the Tonearm Adapter board (see pic_18_USB_header)
26. The Skiratcha tonearm kit includes a white 3-pin cable with plastic plugs on each end. Connect one end of this cable to the “MAIN” header on the Tonearm Adapter board (see pic_19_main)
27. Plug the other side of the cable from step 26 into header TE13 of the PT01’s main board (see pic_20_main_TE13)
28. On the PT01 power supply board, unplug the connector from header TE14. This should have been done in step 4 (see pic_21_TE14)
29. On the PT01 power supply board, remove the screw closest to TE14 (see pic_21_TE14)
30. On the PT01 power supply board, install the Tonearm Adapter board. Insert the PT01’s mounting screw, and make sure it’s tight (see pic_22_mount_TAV2)
31. Insert the red/black 2-wire plug from the Tonearm Adapter board into TE14 (see pic_23_TAV2_TE14)
–Very important: note the wire orientation: black (VCC), red (GND)
32. Plug the cable from step 28 into the “PT01” header of the Tonearm Adapter board (see pic_24_PT01_TE14)

-Reconnect PT01 Wires
33. On the PT01’s power supply board, reconnect the PT01’s black ribbon cable to header TE12 (see pic_25_TE12)
34. On the PT01’s USB board, reconnect the red and white audio cables (see pic_26_USB_cables2)
35. Align and place the top half of the PT01 onto the bottom half of the PT01 (don’t put the 8 screws into the bottom side, yet)

-Skiratcha Tonearm Spring Counterweight
36. Open the lid of the PT01
37. Stage the PT01 to get a good view of the back of the Skiratcha tonearm
38. On the back of the Skiratcha tonearm, grip the ring of the counterweight spring with the supplied black tweezers
39. Angle the tweezers at a 45 degree angle (with the the tip of the tweezers pointing upwards), and pull the spring towards the tonearm’s spring anchor (see pic_27_spring)
40. While keeping the tweezers’ angle at 45 degrees, place the ring of the counterweight spring onto the spring anchor (see pic_28_anchor)

-Optional: Scratch Tension Band
Note: The tension band adds stylus weight above the recommended Shure M44-7 tracking weight of 5 grams. Only add the tension band for scratching.
41. Place the black tension band over the Skiratcha tonearm neck (see pic_29_neck_tension)
42. Attach the tension band between the Skiratcha tonearm neck and the PT01’s tonearm base (see pic_30_tension_base)

-Test
43. Reinstall the M44-7 stylus (see pic_31_stylus)
44. Turn on the PT01’s power and look for the PT01’s red power light (next to the 33/45/78 rpm switch). If the light doesn’t turn on, immediately turn off the power. Check the red/black cables on all of the connectors, and try again.
45. Test the audio output of the PT01 using stereo headphones. Make sure the left and right audio channels are present (see pic_32_headphones). If there are any stereo audio issues, check the wires in step 22.

-Reassemble
45. Close and lock the PT01 lid
46. Flip the PT01 over, and install the 8 case screws into the bottom. Make sure that none of the ribbon cables or wires are stuck between the screw mounts or PT01 edge, before tightening the screws (see pic_33_reassemble)

Posted on January 1, 2017September 3, 2021 by fleshone — 5 Comments

Bass Kill Switch Wiring Guide

Wiring the Bass Kill Switch

Parts needed:
-wire
-DPDT switch
-4-pin female connector

notes:
-the wiring used in this tutorial works for the preamp kit, nanofader 1.2, and nanofader 2.flesh
-wire length depends on where the switch is mounted
-wire length does not affect performance

-Switch Side
1. Solder a wire to the switch terminal as shown in pic_1_wire1

2. Solder a second wire to the switch terminal as shown in pic_2_wire2

3. Solder a third wire to the switch terminal as shown in pic_3_wire3

4. Solder a fourth wire to the switch terminal as shown in pic_4_wire4

-Twist Wires
6. Twist the wires as shown in pic_5_twist. This will help organize the wires into pairs.

-Connector Side
7. Solder one pair of wires to the connector as shown in pic_6_pair1

8. Solder the second pair of wires to the connector as shown in pic_7_pair2

-Complete
9. See pic_8_complete for the completed wire assembly

Posted on December 18, 2016June 9, 2017 by fleshone — 33 Comments

Phono Preamp Kit Install Guide

Phono Preamp Kit Installation Guide for the Numark PT01 Scratch

Parts needed:
-phono preamp kit
-wire of your choice (not included)
-soldering iron
-pliers
-small screwdriver

notes:
-requires the m44-7 tonearm mod
-works with the PT01 Scratch using it’s standard wall power supply, or with the rechargeable battery mod
-works with PT01USB with the rechargeable battery mod (the standard wall supply is not good enough)
-designed for use with the Shure M44-7, but also works with other moving magnet cartridges
-the non-USB version of the PT01 and Vestax Handytrax have not yet been tested
-the front controls of the PT01 will still work after this mod
-the bass kill switch install is not required for operation. Bass kill is disabled by default.
-keep an eye on the wiring, when closing the turntable after install. Don’t let the wires get smashed.

-Prepare Tonearm wires
1. Peel away the glue from the tonearm wires (see pic_1_remove_glue)

2. Unsolder the tonearm wires from the main PCB (see pic_2_unsolder_tonearm)

-Remove Capacitors
3. Remove PCB screws (see pic_3_remove_PCB_screws)

4. Remove capacitors C8 and C18 from the main Numark PCB (see pic_4_remove_C8_C18). See pic_5_C8_C18_bottom for a bottom view of the PCB, when the capacitors are removed

-Add Line Audio Wires
5. Strip about 3mm of insulation from two short wires (about 2 inches long each).
6. Drop the stripped wire into the existing capacitor hole (see pic_6_add_line_audio_wires)
-note that the guide uses white wire for Left channel audio, and red wire for Right channel audio

7. Solder the wires on the bottom side of the PCB

-Remount the main PCB
8. Remount the main PCB by replacing the 4 previously removed PCB screws (see pic_7_replace_PCB_screws)

-Mount Phono Preamp
9. Remove one of the wide head start/stop switch mounting screws (see pic_8_remove_switch_screw)

10. Remove the pan head GND mounting screw (see pic_9_remove_GND_screw)

11. Bend Numark capacitors C7 and C17 into a horizontal position, so they do not touch the bottom of the new preamp. Note that The Numark circuit below the new preamp will no longer be used, so those capacitors can be unsoldered or cut out with cutters, if required. Typically, they can be easily bent into a horizontal position. The horizontal position of those 2 capacitors can be seen in pic_2_unsolder_tonearm.

12. Use the pan head GND mounting screw to mount the phono preamp on the start/stop switch mounting hole (see pic_10_mount_preamp)

13. Use the wide head start/stop switch mounting screw to re-secure the GND terminal (see pic_11_replace_GND_screw)
-note: we are just swapping screws here, so the smaller head screw mounts the phono preamp

-Connect Audio Wires
14. Loosen the screws of the green terminal blocks (all of them), so that the jaws of the terminal blocks are open.
15. Place the tonearm wires into the AUDIO_IN phono preamp terminal block and tighten the terminal block screws (see pic_12_connect_tonearm_wires)

16. Place the Line audio wires into the AUDIO_OUT phono preamp terminal block and tighten the terminal block screws (see pic_13_connect_line_wires)

-Connect Power Wires
17. Solder wires to the PT01 power PCB regulator as shown in pic_14_solder_power_wires. These wires are long to allow the turntable case to flip open for future mods.

18. Place the power wires into the phono preamp power terminal block, and tighten the terminal block screws (see pic_15_connect_power_wires).

19. Position the new wires, so they don’t get pinched by the turntable mounting screws.
20. Reassemble the turntable

Posted on April 26, 2016 by fleshone — 12 Comments

Ultrapitch (simplified) Mod for Numark PT01

This is a Simplified Ultrapitch Modification for the Numark PT01

Parts needed:
Resistor between 1k ohm and 2k ohm

notes:
-when the platter speed switch is set the 33rpm, the platter will spin at ~22rpm
-when the platter speed is set to 45rpm, the platter will spin at 33rpm
-this mod can only be done on newer (example 2014) PT01 turntables
-older models, such as circa 2006, have a different motor control circuit and require a different mod
-the new models have the orange potentiometer shown below, where the older models have a blue potentiometer
-download the “RPM – the turntable speed accuracy checker” iPhone app to test platter speed
-this mod came from a forum comment by Rasteri, which said “Replace VR1 with a 2K resistor and that lowers the 33RPM speed to about 20RPM”
-buy Dj Focus’ ultrapitch mod for full control, and to support the skratch community
-works with ultrapitch 7” records, such as skiratcha breaks from DJ A1

-Remove and Replace VR1
1. Unsolder the potentiometer in VR1

2a. Solder a resistor across the 2 pins shown in pic_1_replace_VR1. This picture shows a 2.2k ohm resistor in place of VR1. This results in a platter speed of ~20rpm, when the platter speed switch is set to 33rpm, and ~32rpm when set to 45rpm (varies between turntables).

-Alternate VR1 values
2b. It was found through test that a 960 ohm resistance across VR1 results in a clean 33rpm, when the platter speed switch was set to 45rpm. This resistance results in 22rpm, when the platter speed switch is at 33rpm. A 820 ohm and 150 ohm resistor were connected in series to achieve ~970 ohms. The resulting speed vs. resistance value depends a lot on the friction between the spindle and the platter. A value between 1k and 2k ohm should work great. see pic_2_replace_VR1_series

Posted on April 26, 2016 by fleshone — 6 Comments

3D Printed Tonearm Clip Install for Numark PT01

Adds 3D Printed Tonearm Clip to the Numark PT01

Parts needed:
3D printed tonearm clip

notes:
-only for use with 3D printed tonearms

-Install 3D Printed Tonearm Clip
1. Remove white backing paper from tonearm clip
2. Stick 3D printed tonearm clip onto existing PT01 tonearm clip. Make sure the orientation of the 3D printed clip base matches the existing PT01 tonearm clip, before sticking (one side is round, one side is square)

Posted on April 22, 2016 by fleshone — Leave a comment

Faceplate Removal for Numark PT01

How to Remove the Numark PT01’s Metal Faceplate

Parts needed:
–plastic pick, such as a guitar pick
–plastic putty knife (any plastic putty knife from your local hardware store will work. Preferably, not more than a couple inches wide)

notes:
-always use plastic tools for the procedure to avoid faceplate and plastic housing does not get scratched
-the metal faceplate is applied to the plastic turntable housing with heavy double sided tape
-the adhesive sticks to the faceplate better than the housing, so there is little damage to the housing, when removed
-the plastic housing below the faceplate is black
-there is no need to paint or replace the faceplate, if a black faceplate is desired
-removing the faceplate exposes a spring and a hole for the spring, which is a good place to add a switch or knob
-the spring is attached to the housing with a single screw (no solder). Remove the screw to remove the spring.

-Remove the tonearm
1. See tonearm removal guide

-Start at the 45 Adapter
2. Starting at the 45 adapter hole, use a plastic pick and gently pry up the faceplate. The 45 adapter hole is a good place to start, because it doesn’t have a beveled edge to protect the faceplate.
3. Lift the corner of the faceplate from the 45 adapter hole enough to fit a second plastic pick or putty knife along the outer edge of the faceplate (see pic_1_45_adapter)

-Pry Outer Edge
4. Work around the outer edge of the faceplate. Be careful not to pry too far up, or the faceplate will bend (see pic_2_outer_edge)

-Pry Inner Faceplate
5. Use a plastic putty knife to pry the deeper sections of the faceplate, such as between the platter and the EQ controls (see pic_3_putty_knife)

-Lift Faceplate Off
5. Use your hands to lift/pry the faceplate the rest of the way off. Be careful not to cut your hands on the edge of the metal faceplate.

-Mount a Start/Stop switch in the Spring Hole (optional)
6. See start/stop switch guide

Posted on April 22, 2016April 22, 2016 by fleshone — 15 Comments

Start/Stop Switch Install for Numark PT01

Adds start/stop switch to the Numark PT01

Parts needed:
SPST (Push 0n – Push off) Switch

notes:
-any push on – push off or latching switch with a greater than ~300mA rating will work for this
-the switch listed above was used for this install
-if you remove the PT01 faceplate, this switch fits in the existing spring hole without drilling (remove the spring, which is attached internally with one screw)

-Remove the Existing Switch
1. Unsolder and remove the existing start/stop switch (see pic_1_remove_switch)

-Mount the New Switch
2. Mount the new switch in a preferred location (see pic_2_mounted switch). For this guide, the switch is mounted in the existing spring hole with the faceplate removed (see faceplate removal guide for instructions on removing the faceplate).

-Solder Wires
3. Solder 2 wires to the existing switch PCB (see pic_3_add_wires)

4. Solder these wires to the new switch (see pic_4_connect_switch)

Posted on April 21, 2016June 12, 2016 by fleshone — 19 Comments

Platter Bar Install and Comparison

How to Install Platter Bars for the Numark PT01

Parts needed:
platter bars
needle nose pliers

Optional Parts:
silicone grease

notes:
-there are at least 2 different platter heights for the PT01
-the older model, circa 2006, has a low platter height
-the newer model, circa 2014, has a high platter height
-one clear difference between models is that the belt holder attached to the motor is plastic on the 2006 model, and metal on the 2014 model

-Remove Platter
1. Use a pair of pliers to push off the spindle clip (see pic_1_remove_spindle_clip)

2. Push on one edge of the platter to raise the opposite edge

3. Lift the platter using the raised edge, and remove platter (see pic_2_remove platter)

-Install Platter bar
4. Remove white adhesive backing from platter bar (see pic_3_platter_bar_backing)

5. Place the wide edge of the platter bar flush against the turntable wall (see pic_4_place_platter_bar)

6. Cut or break off the 2 nubs on the bottom side of the platter (they have no functionality). This will stop the nubs from potentially hitting the platter bars. See pic_6_cut_nub

7. Reinstall the platter and platter clip.
a. wrap the turntable belt around the inner edge of the platter first
b. place the platter on the spindle, while pulling on the belt with one finger to keep tension
c. wrap the belt, which is being held with one finger, around the motor spindle
d. reinstall platter clip using pliers

8. Turn on the motor and let the platter spin. If the platter rubs on the the platter bars, push down hard on the platter and move it back and forth in a baby scratch motion. This will grind down the platter bar’s plastic housing. Turn on the motor again to see if the platter still rubs on the platter bars. Repeat until the platter stops rubbing on the platter bar during playback. See “How to Grind Down Platter Bars Video”, below:

How to Grind Down Platter Bars Video:

Platter Bar Comparison Video:

Posted on April 18, 2016 by fleshone — Leave a comment

Stock Needle vs. shure M44-7 + Pyle PP444 (objective comparison)

This comparison includes a needle and tonearm comparison table, spectrums, and a tap test video.

Turntable 1:
-stock Numark PT01 USB

Turntable 2:
-modified Numark PT01 USB
–3D printed tonearm
-shure M44-7 cartridge and needle
–Pyle PP444 stereo phono preamp (requires preamp mod)

notes:
-data was taken to objectively compare the stock ceramic needle and tonearm to a 3D printed tonearm with M44-7 needle and Pyle PP444 preamp on a Numark PT01
-data includes output level testing using a “Cardas Frequency Sweep and Burn-In Record” as source material
-audio data is taken with an Audio Precision APx515 audio analyzer
-The Pyle PP444 phono preamp was chosen for it’s very low cost, and +9V (single rail) operation
-a much higher quality preamp can be used if desired
-top level view, the data says that the output level is similar between turntable 1 and turntable 2
-the m44-7 has a bit more low end
-the ceramic needle has a bit more high end
-the m44-7 is louder with a 1kHz tone audio source
-the ceramic needle is louder with a pink noise audio source
-the ceramic needle has a lower noise floor when the platter is moving
-the m44-7 has a lower noise floor when the patter is not moving
-the m44-7 has less record wear
-the m44-7 has better anti-skate performance when bouncing (i.e. more likely to land back on the correct skipless scratch section of the record)
–platter bars will help with bounce performance for both needles

-Needle and Tonearm Comparison Data
1. See the Needle and Tonearm Comparison Table, and associated spectrums

Needle and Tonearm Comparison Table

Test Description	Ceramic Needle (mVrms)		M44-7 with Pyle PP444 Preamp (mVrms)
Test Description	Channel 1	Channel 2	Channel 1	Channel 2
1kHz tone, full volume, flat EQ	245	219	307	276
1kHz tone, full volume, Hi EQ	284	251	364	327
1kHz tone, full volume, Low EQ	198	176	276	242
Tonarm docked, no input (noise floor test)	0.752	0.735	0.407	0.397
Tonearm undocked, no input (noise floor test, platter moving)	1.63	1.69	7.78	7.1
Pink Noise, full volume, flat EQ	505	451	322	327
Pink Noise, full volume, Hi EQ	673	585	351	363
Pink Noise, full volume, Low EQ	293	214	285	280

table notes:
-all data taken with Audio Precision APx515
-both turntables were wall powered for all tests
-the 1kHz and pink noise audio source was generated by playing source material from the “Cardas Frequency Sweep and Burn-In Record” vinyl record
-“Cermaic Needle” refers to the Numark PT01 stock needle
-“M44-7” refers to a shure M44-7 cartridge mounted on a 3D printed tonearm
-“with Pyle PP44” refers to a modified Numark PT01, where the existing preamp is bypassed, and a Pyle PP444 is installed in it’s place
-“flat EQ” refers the tone control knob in center position
-“Hi EQ” refers to the tone control knob in “High” position
-“Low EQ” refers to the tone control knob in the “Low” position

-Spectrums
2. See spectrums

M44-7 plus Pyle PP444, 1kHz Tone, Full Volume

M44-7 plus Pyle PP444, Pink Noise, Full Volume

-Bounce Performance
3. See the tap test video

Posted on April 17, 2016April 17, 2016 by fleshone — Leave a comment

3D Printed Tonearm Counterweight Adjustment

How to Adjust the Counterweight for a 3D Printed Tonearm

Parts needed:
3D printed tonearm

notes:
-the scale used for test is a 5g (maximum) stylus scale, with 0.01g precision
-the sure m44-7 needle expects 3-5g of weight for optimal tracking and audio performance

-Check Weight of Needle
1. Check the weight of the needle using a stylus scale (first measured weight is at 3.48g, see video)

-Adjust Counterweight
2a. Increase the counterweight by removing tension from the counterweight rubber band. In this case, the rubber band moves from the inside position to the outside position to reduce tension (second weight is at 4.26g, see video).

2b. Tension can also be adjusted by using a rubber band of a different thickness, and also by stretching or releasing tension in the section of the rubber band between the base of the tonearm and the back of the tonearm