UCD180 questions

wytco0 said:
I just screwed mine through the case using some M3 from a box of assorted screw I picked up in Maplin.

Curiously I think I have the very same box...

It's about the only place I managed to find a supply of assorted useful looking bolts. However, probably like you, I find the short M3s to be the most useful one, and consequently have non left, and a box of the other sizes...

I will try farnell for some.

Whilst we are on the topic though. Any thoughts on assorted standoffs? Farnell again? I haven't found anywhere on the highstreet which can sell, say, M4 standoff nuts...
 
Of with the caps and drilling away the treads.
 

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Jan-Peter said:


You can put the /ON always on the GND line, but you can have some noises when you switch the amp off. Because the capacitors are discharging quit slow so you don't have a fast/sharp moment when the amps switch off. Please use the circuit in the attachment, every small NPN transistor will work. AC1 and AC2 are the secondairy voltages.

Regards,

Jan-Peter

Your mute circuit.

No yet tested.
 

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Stef1777,

Looks ok!

But why do you use the Schaffner netfilter?

In the most netfilters are mounted Y-capacitors (from live and neutral to ground) this can affected your sound because of earthcurrent. Bruno wrote in this topic that he never advise to use netfilters, becuase this degreed the sonic performance of your hifi setup.

Thereby with the UcD180 you don't need them for EMI suppression.

Regards,

Jan-Peter
 
Jan-Peter said:
Stef1777,

Looks ok!

But why do you use the Schaffner netfilter?

In the most netfilters are mounted Y-capacitors (from live and neutral to ground) this can affected your sound because of earthcurrent. Bruno wrote in this topic that he never advise to use netfilters, becuase this degreed the sonic performance of your hifi setup.

Thereby with the UcD180 you don't need them for EMI suppression.

Regards,

Jan-Peter
Can somebody elaborate on that? Is it advisable to not use that kind of filter on the amp or not even on other place in the house? Is it just the capacitor to earth or is it the whole ciruit? If you can't use these filters, how do you protect your devices against overvoltage (is a varistor also 'bad'?) or filter out the noise in the electricity?

Thanks!
 
Jan-Peter said:


Indeed you are completly right, there is already a pull up resistor in the UcD180/400. So you can forget the +15V line by the transistor. A simple open collector output is already sufficient. There are all protection diodes inside the UcD180/400 so a higher voltage (max. 50VDC) is also no problem.

Regards,

Jan-Peter

I tried the circuit alone (not connected to the UcD). I tried with an 2 x 25V transformer.

When the power goes on, the GND is well switched but I have 42 Ohms. I used an 2N2222 from my stock.

Is this normal?