In one of the older threads about cd-player tweaking, someone suggested this as a method for filtering RF “junk” wich “toy motors” seem to produce. Tweak consisted of using 3 1 nF ceramics caps: one from + to – terminals on the motor, others from + and – terminals to the ground.
I’ve used it on a good ol’ Mabuchi in KSS-151a transport recently. As a result I ended up keeping only the on the motor terminals, since the motor wouldn’t spin at all when other two were used.
The fact that there was an empty space for a non-polarised capacitor right between the + and – motor terminals on the motor board of my player (no reference to it in the service manual) got me thinking
What would be the teorethycal benefits and/or problems (excluding the obvius
) of such tweak?
Cheers
I’ve used it on a good ol’ Mabuchi in KSS-151a transport recently. As a result I ended up keeping only the on the motor terminals, since the motor wouldn’t spin at all when other two were used.
The fact that there was an empty space for a non-polarised capacitor right between the + and – motor terminals on the motor board of my player (no reference to it in the service manual) got me thinking
What would be the teorethycal benefits and/or problems (excluding the obvius
) of such tweak?Cheers
I_Forgot said:
For a commercial product the question wouldn't be: 'do we need it there?', but rather: 'can we do without?'.
Apparently the answer to the last question was 'yes'
A cap may filter out some of the garbage coming from a motor, but a separate small power supply would be better.
If there's already a space for a capacitor just try it and see (hear) what happens, if anything.
Remco
Rambi said:
I've already bypassed the motor's + and – terminals with a regular 1 nF ceramics cap, I think I percieved a suble increase in overall clarity and resolution. My question would be if this is the correct implementation, or there is a better (more effective) way?
siezien said:
Unfortunatly, I don't have any pics, but the modification is rather easy to implement. I've soldered the 1 nF ceramics cap from + to – terminal on the spindle motor. The cap is regular of the shelf ceramics, nothing special or out-the-ordinary. I don't know if it would be beneficial and/or cost effective to use something different. I did plan to find out by starting this thread, but that isn't working out as expected until now...
OK, here are the threads that contain the references to the tweak by multiple people:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=28224&highlight
Bernhard[/i][b] Motors with brushes make a lot of noise. Acoustical and electrical (RF). Radio controled cars ( toys ) have ceramic caps across the Mabuchi motor terminals and to ground from each terminal. The transports do not.[/b][/quote] [url]http://www.diyaudio.com/forums/showthread.php?s=&postid=1033626&highlight=#post1033626[/url] Hi Guido said:
My primary concern would be the effective suppresion of RF without getting in the way of the motor controller (like it was the case with bypassing the motor with 100 nF MKT cap
)...I would like to invite people to share their opinions about the subject (especially the authors of the quotes mentioned!)...
The last quote offers somewhat a different solution, using the caps from + and – terminals to ground only (without using the one directly on the motor terminals).
Which of these two examples would be best?
Thanks in advance
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