The first part of the Philips EE rhytm machine

[Frankje]

Hi all !
Thanks to the library of forum member Ingo, I could draw the layout of the rhytm unit made around the EE Philips system.
This first part is the plan of the tempo generator, followed by a tempo multiplier ( for the shuffle hihats ) and two dividers.
Each stage has 2 outputs ( example 8 and 8' ). They can be freely connected to the sound generator circuit ( I will finish this in the weekend ). When 8 is a high output, then 8' is low and vice versa.
The tempo generator is an astable multivibrator around the LM3900.
The multiplier is a monostable triggered by 2 states of the astable vibrator.
Then the dividers are build around discrete flip-flops.

Who dares to build this huge circuit ?
Please leave comments and improvements.
Greetings
:wink:

[Frankje]

:-)
This is the second part of the EE Rhytm box. This board has the three drum sound generators ( bass, hihats and snare drum ). By connecting these to the divider outputs ( 8 or 8' or 16 ... ), you can create the patterns.
By using switches on the main console, you can make this a bit easier.
The circuit uses a noise generator but since noise starts with a power supply of about 9V, I've created a circuit around the LM3900 opamps to produce this noise.
When you connect capacitor C15 on the sound board between terminal A2 and E4+, you get a "kraftwerk" sound.
You can experiment a lot with this circuit to produce different sounds, just by touching the noise generator, it's very sensitive !

Sound examples can be found on : http://soundcloud.com/synthed-mind/changing-loop and http://soundcloud.com/synthed-mind/simp ... pen-hihats
These loops were recorded without effects or mixing, just the plain EE sound.

Happy building !

[Lutz]

Hi Frankje!

Nice work at all! Strictly simple, but very interesting and astounding.

It's not my favourite thing of electronic, but I felt I should leave just a positive comment.

Regards,
Lutz

[Ingo63]

Hi Frankje,
wir hatten ja schon Kontakt, und ich weiß dass du deutsch lesen kannst.
Ich werde dein Aufbau noch nachbauen und hoffe mehr von dir hier zu lesen.
MfG
Ingo

[JeanLuc7]

Hi Frankje,

I was thinking about spending some delightful hours with your development this weekend (long weekend in Germany, bank holiday on Thursday). To save some space on my table I thought of the old-fashioned method of stacking the two boards (like in the EE2008 TV construction). So I tried to understand what has to be connected to the switchboard. Currently I only see a connection to the push button (pins 12/13). I also recognize the connection to the power supply (battery).

But then things get a little bit lost. First I miss the connection to the loudspeaker. You write about connecting Pins 8/8a. Then there are some inputs (outputs) like snare and bass - you see I am a bit confused. I also read your other post with the two photos. Actually they differ a bit from your drawing, but I seem to recognize a connection to the loudspeaker there - but was not able to find out where the wires are connected to. Of course a circuit diagram would solve my problems, but maybe you can also support me with some additional information.

Thank you, looking forward to your answer and to some interesting construction hours,

Frank / JL7

[Frankje]

You're completely right !
The answer is that I have omitted the speaker, since it cannot handle the deep bassdrum (it comes out like cracled ).
So I did not use it. You have to connect an external amplifier to the common connections of the resistors R7 and R8 near the mixer potis.
The trigger inputs ( snare, bass, hihats ) can be connected to the connections marked 2, 2', 4, ...
Use only one at the same time.
Of course, you can connect at the same time bass and snare at for example connection 4.
The layout of the drawing is correct.
Happy building !

[Frankje]

A small improvement with big conscequences ...
Instead of the OA95 diode, use a BC238 or BC547 transistor. Connect the base to ground and the emitter to the 470 k resistor.
Disconnent the capacitor mounted on top of the LM3900
This gives better noise generation and the snare and hihats are sounding much better.
Experiment with different transistors till you find the sound you like.
Have fun !