transformator in the tb's cpu

[WeAreAs1 at aol.com]

In a message dated 8/13/00 3:27:14 PM Pacific Daylight Time, ampe at swipnet.se 
writes:

<< Looking at the scheme real close made me discover
 this important transformator located next to the
 cpu. It is connected to pin 42 and pin 1 namned
 CLO & CL1 on the CPU. I have the feeling that this
 little component is rather important for the 
 functianallity of the sequencer itself  >>

Transformators?  Don't you mean Transformatators?   ;)

No, the transformer is not important to the sequencer.  It's part of a little 
voltage multiplier circuit (like what you find in most switching power 
supplies), and it works in conjunction with a very high frequency oscillator 
to help provide the higher voltages required by some of the TB-303's analog 
circuits (but not the sequencer).  

About twenty 1.5 volt batteries would be required in order to provide these 
necessary voltages, but the sequencer section can easily run on just four 
batteries.  You can provide those same voltages with less difficulty, and 
with *much less less noise* by using standard linear power supply techniques. 
 The only reason the 303 used that particular method was so they could fit 
all the parts into a very small case, and use fewer batteries.  I'm sure the 
designers would have preferred to use a linear supply, if they had the space.

Two questions:

1.  Did you check to see if your new CPU unit is a µPD650C-133?

2.  What supplier did you buy the CPU from?

FYI, Synth-DIY is a two-way street.

Michael Bacich