UCD180 questions

[stef1777]

Originally posted by Jan-Peter


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.

[stef1777]

The UcD180 mono block.

No yet finish...

[Jan-Peter]

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

[paradigm]

-stef1777

Hi!
Your picture shows a connector with filter. I'm sure I've read that it is NOT recommended. You should use one without the filter (X2 caps).

Other than that, it looks VERY nice.

BR
Roland

[Hans L]

Originally posted by Jan-Peter
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!

[ingomar]

See my pictures in the UCD400 thread

Nice work.
ewildgoose, in the background of the picture appears something which I think looks like a mutlichannel potentiometer. If yes, how much was it?
Everything I could find was for outragus prices (US$ 300 and up )


-- Ingomar

[stef1777]

I already have iec netfilter on others equipements without problem. I'll try with and without if time.

[stef1777]

Originally posted by Jan-Peter


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?

[Jan-Peter]

Stef,

Where do you have 42 ohm? From Collector to ground?

Seems quit highe but is ok when you like to pull down the /ON line.

Regards,

Jan-Peter

[stef1777]

Originally posted by Jan-Peter
Stef,

Where do you have 42 ohm? From Collector to ground?

Yes.

I can may be try to adjust the resistor to have a lower impedance. I'll try when I will have received my slime line toroid transformers.