Hey Guys,
I have a question about the psu, is use this board to power my Aleph J. One thing i noticed was that when i power on the amp, only the + voltage led is lid, after about 5 minutes the - voltage is also burning, is this normal behavior?
for you're information, i use a 500va transformer, nichicon caps, standard BOM parts, and for a softstarter I use a couple of ntc thermisters from rinkerntrafo.nl (Inschakelstroom begrenzing 625VA)
I have a question about the psu, is use this board to power my Aleph J. One thing i noticed was that when i power on the amp, only the + voltage led is lid, after about 5 minutes the - voltage is also burning, is this normal behavior?
for you're information, i use a 500va transformer, nichicon caps, standard BOM parts, and for a softstarter I use a couple of ntc thermisters from rinkerntrafo.nl (Inschakelstroom begrenzing 625VA)
its only the led that takes 5 minutes, the rail itself is up, hence the - rail led on the Aleph J is up, i have some pictures on my OneDrive account:
http://1drv.ms/1LK79gs
there are 2 things you dont see on the pics and that is the thermistor section and the on/off switch.
http://1drv.ms/1LK79gs
there are 2 things you dont see on the pics and that is the thermistor section and the on/off switch.
checked the voltages, they are the same on both sides when amp is going up 21,4v measured at psu out, but i discovered something else, when i disconnect the speakers and turn the amp on (btw its a aleph J in combination with Mez B1) both leds immediately turn on. does anyone have a clue, cause i dont
I am making an order list of parts for the F& and power supply.
Mayber someone can help me?
I used to buy the Panasonic TSUP or TSHA caps. These are not available anymore.
Is Nichicon a good replacement?
Which series do you think is the best?
In the First watt F6 the caps are rated at 25V. Isn´t this too small for a rail voltage of 23V?
Mayber someone can help me?
I used to buy the Panasonic TSUP or TSHA caps. These are not available anymore.
Is Nichicon a good replacement?
Which series do you think is the best?
In the First watt F6 the caps are rated at 25V. Isn´t this too small for a rail voltage of 23V?
For caps on the PSU3, I went with Nichicon LS series. I just soldered them on last night. 18,000uF each.
LLS1H183MELC Nichicon | 493-7271-ND | DigiKey
LLS1H183MELC Nichicon | 493-7271-ND | DigiKey
Being that 23V is less than 25V, there really isn't a problem at all.
If you choose a cap with a higher voltage rating, it will give longer life when operated at 23V.
Nelson uses 25V caps in the factory-built Firstwatt amps.
Perfect. Good choice!
That looks great!
My parts are almost here. They were cleared from customs and I should have the boards in a few days.
It elevates PSU ground about 10ohms above the chassis, so the signal ground won't mix with the chassis ground.
BUT, since it's a thermistor, if there is an electrical fault, it will reduce to about 1/4 ohm and stay intact with real current flowing through it.
Safety and signal isolation. All in one nifty little package.
BUT, since it's a thermistor, if there is an electrical fault, it will reduce to about 1/4 ohm and stay intact with real current flowing through it.
Safety and signal isolation. All in one nifty little package.
The voltages may be around 10% higher than under full load. A variac would be good for this test.
You have 50V caps, rated at higher than the expected 25V, so no problem. I'd burn in the caps
with no load for an hour or so, before using with the amp circuit and a load.
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