Three of Twin-T. Each one has different value of capacitors, normally higher value you put, lower frequency you get. I ended up selecting 470nF, 100nF and 22nF, however it's worth trying different value to meet your taste. And led also changes the tone depending on its color.
All decoupling capacitors, 100nF are soldered underneath the boards.
FACEPLATE LAYOUT
6hp faceplate layout. The dimension is 30mm x 129mm.
It's actual size so you can use it as a drilling template.
Potentiometer: 7mm
3.5mm jack: 6mm
Mounting screw: 3mm
MFOS VC LFO with Sync Input Modification Schematics& BOM MFOS VC LFO : LINK Sync Input Modification : LINK STRIPBOARD LAYOUT -All dec...
-All de-coupling capacitors, 100nF, are soldered underneath the boards.
-To reduce the depth of a module, I attached the board LM13700 is placed behind other two boards by using jumper pins like the pic above, which is a little bit tricky but not that hard to do.
FACEPLATE LAYOUT
The layout is actual size so you can use it as a drilling template.
-Potentiometer : 7mm
-3.5mm jack : 6mm
-Toggle switch : 6mm
-Screw hole : 3mm
In my case, adding a potentiometer between motor and power, this quick method to control motor speed didn't work at all so I used PWM us...
In my case, adding a potentiometer between motor and power, this quick method to control motor speed didn't work at all so I used PWM using 555 timer to control motor speed. Some benefits of using 555 timer are I can add CV and gate inputs. Probably the quick method would work with other cassette player.
SCHEMATIC
UPDATE on 20220913:
With 1uF, the motor rotates non-linearly. So you can stick with 200nF for linear rotation.
UPDATE on 20220810:
For better speed control, I replaced 200nF with 1uF and 'Linear' 100k potentiometer with 'Log' 100k one. The schematic above has been updated.
Instead of using pin4 of 555, I switched to pin2 for gate input. Both works fine but conversely. It's up to you. But keep that in mind when using pin4, switch pin of 3.5mm jacks should connect to Vcc and disconnect Vcc from pin4.
STRIPBOARD LAYOUT
UPDATE on 20220913:
With 1uF, the motor rotates non-linearly. So you can stick with 200nF for linear rotation.
UPDATE on 20220810:
For better speed control, I replaced 200nF with 1uF and 'Linear' 100k potentiometer with 'Log' 100k one. The stripboard layout above has been updated.
This cassette player has a line output which jack is stereo one but actually left and right signal summed to mono in the circuit. One thing bothering me is its output gets mute when I plug mono cable into it because 'ring' pin of stereo jack was in contact with ground pin of mono plug. If you use stereo split cable, nothing wrong with it, however if you just want a mono signal like me, unsolder the stereo jack and cut the two legs corresponding ring side.
And I encountered some issue while using CV with my eurorack modules. Those seemed like ground issue. After some investigating, I found out its line out jack's ground was floating. So you need to connect the ground pin of line out jack to other ground point.
THOMAS HENRY CMOS ADSR Original Schematics: LINK1 , LINK2 STRIPBOARD LAYOUT -All diodes are 1N4148 -555 timer chip should be CMOS one like...
The layout is actual size so you can use it as a drilling template.
I used 12mm thick merbau edge glued panel and M3(13mm long)bolts. And I tapped the holes with a M3(0.5mm pitch) tapping bit. If you are using different size of wood and bolts, please be careful the tip of M3 bolts don't touch the pcb.
As a finish, I applied boiled linseed oil which is good to darken the wood, but its smell is not pleasant and lasts so long.
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