No, no problem I hope!!! Now I'm taking a break from building. Next days I try to make It sound!
Capacitor near AC connector
Hi, I finished the enclosure and now my Aleph 30 sounds!
I have a question about capacitor to put near AC connection. Schematic shows 0,47 microfarad 250 V AC regarding 120 V american grid. Now I have 220 V grid and I have bought a capacitor 250 V AC - 630 V DC. It is difficult to find a capacitor more than 250 V AC (my capacitor is also quite big...).
I don't know the function of this capacitor and I ask you if it is a good thing use it.
And 250 V AC is to low using a tension grid 220 V?
Thank you
Hi, I finished the enclosure and now my Aleph 30 sounds!
I have a question about capacitor to put near AC connection. Schematic shows 0,47 microfarad 250 V AC regarding 120 V american grid. Now I have 220 V grid and I have bought a capacitor 250 V AC - 630 V DC. It is difficult to find a capacitor more than 250 V AC (my capacitor is also quite big...).
I don't know the function of this capacitor and I ask you if it is a good thing use it.
And 250 V AC is to low using a tension grid 220 V?
Thank you
I would not use it. Actually you need a capacitor designed to be wired
across the lines so if they fail, they don't short circuit:
http://www.vishay.com/docs/28153/anaccaps.pdf
Something like this should work:
F339X144748MKP2T0 Vishay / BC Components | Mouser Canada
across the lines so if they fail, they don't short circuit:
http://www.vishay.com/docs/28153/anaccaps.pdf
Something like this should work:
F339X144748MKP2T0 Vishay / BC Components | Mouser Canada
Thank you!
Sould this capacitor CAP SUP X1 PP 0.47UF 480VAC RADIAL - PHE844RD6470MR30L2 (Fnl) | eBay work fine too???
Sould this capacitor CAP SUP X1 PP 0.47UF 480VAC RADIAL - PHE844RD6470MR30L2 (Fnl) | eBay work fine too???
you can do without that cap ;
and , anything from 0.22 to 0.47uF will work , as long is mains voltage rated and having X1 in title
Safety Capacitors First: Class-X and Class-Y Capacitors
and , anything from 0.22 to 0.47uF will work , as long is mains voltage rated and having X1 in title
Safety Capacitors First: Class-X and Class-Y Capacitors
Thanks Zen Mod.
Now I'am using my Aleph without that capacitor. It sounds without problem, just a very little hum that it can be heards close the tweeter. Hum doesn't change when volume goes up. There are no this noise when only power amp is turned on. When I turn on preamp or surce I can hear hum from tweeters. I dont'know if it is a normal thing. May be a ground loop but it is insignificant noise during listening ad hithout music when you are 2m from speakers. May that capacitor reduce that hum?
Now I'am using my Aleph without that capacitor. It sounds without problem, just a very little hum that it can be heards close the tweeter. Hum doesn't change when volume goes up. There are no this noise when only power amp is turned on. When I turn on preamp or surce I can hear hum from tweeters. I dont'know if it is a normal thing. May be a ground loop but it is insignificant noise during listening ad hithout music when you are 2m from speakers. May that capacitor reduce that hum?
nope; that cap is for suppressing mains garbage - think much higher frequencies
hum can be either from not so clean wires/ground routing , or from preamp itself
hum can be either from not so clean wires/ground routing , or from preamp itself
DC offset mesurement
Hi,
I have got a new multimeter and now I'm re-mesuring DC offset.
Shall I connect the speakers during mesurement or not?
Thank you!
Hi,
I have got a new multimeter and now I'm re-mesuring DC offset.
Shall I connect the speakers during mesurement or not?
Thank you!
I have checked DC offset for both channel and after one hour it's about 35 mV for both channel (<100 mV datasheet). Does it depend from right matching MOSFETs?
Voltage across bias resistor
Hi,
after DC offset I'm measuring voltage across bias resistor (0,47 ohm near mosfet).
I read 0,32 V.
I see that value slovly decrease during increase amp temperature.
It should be 0,25 V.
What does it means?
I have no changed the BOM from BrianGT list...
Shall I measure bias voltage with hot amp?
Hi,
after DC offset I'm measuring voltage across bias resistor (0,47 ohm near mosfet).
I read 0,32 V.
I see that value slovly decrease during increase amp temperature.
It should be 0,25 V.
What does it means?
I have no changed the BOM from BrianGT list...
Shall I measure bias voltage with hot amp?
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