Thank you so much, I’m looking for 140 ohm resistor but I don’t have it. I will use 150 ohm instead and report back.
Thanks
Sajjad
Yeah, exact value won't make any difference at all. 150ohm is fine.
I used another 150 ohm and before it burnt, I measured +ive voltage.
I can confirm that regulator works, I can adjust the voltage, I reached 38 volts before it burnt and I have run out of supplies
However the resistor on -ive rail works absolutely fine, problem is on positive rail only, one option would be to use a higher wattage resistor but please guide me if I should or not?
Thanks
Sajjad
I can confirm that regulator works, I can adjust the voltage, I reached 38 volts before it burnt and I have run out of supplies
However the resistor on -ive rail works absolutely fine, problem is on positive rail only, one option would be to use a higher wattage resistor but please guide me if I should or not?
Thanks
Sajjad
I used another 150 ohm and before it burnt, I measured +ive voltage.
I can confirm that regulator works, I can adjust the voltage, I reached 38 volts before it burnt and I have run out of supplies
However the resistor on -ive rail works absolutely fine, problem is on positive rail only, one option would be to use a higher wattage resistor but please guide me if I should or not?
Thanks
Sajjad
Something else must be wrong. The resistor should only be dissipating 3.2mW.
Check the polarity of D5 and D6, and the resistance of R7. (Also check D5 and D6 for being shorted.)
I can see the polarity in your last picture -- it's correct.
Just for debugging, replace the burned resistor with something on the order of 10K or 20K. Then see what voltage you're getting on the base of TR5. (It should be two diode drops below your rail -- or about 54.5V.)
Just for debugging, replace the burned resistor with something on the order of 10K or 20K. Then see what voltage you're getting on the base of TR5. (It should be two diode drops below your rail -- or about 54.5V.)
(This is a bit embarrassing, but I guess it is DIY. )
It's all good, it's all part of the adventure!
Thanks for the updated schematics.
My power supply consists of 2x40v 500VA toroid, 2 33000uf Kemet with 2 bridge rectifiers as suggested by Jeff.
I am going to use this, one for each channel, like Nap 135, in two separate boxes. I love my ears so I will not be driving it hard.
1-Do I still need to install a fan with heat sink, like in 135?
2- is there any wiring precaution I need to undertake when wiring one regulator and one amplifier board to above mentioned power supply?
Thanks
Sajjad
I am going to use this, one for each channel, like Nap 135, in two separate boxes. I love my ears so I will not be driving it hard.
1-Do I still need to install a fan with heat sink, like in 135?
2- is there any wiring precaution I need to undertake when wiring one regulator and one amplifier board to above mentioned power supply?
Thanks
Sajjad
No, that's the impedance (although that number will also factor into the amount of heat generated).
But I was mostly looking for the sensitivity number. It's quoted in the link you posted as 92dB, which is reasonably high. I very much doubt you'd need a fan.
What size is the room?
But I was mostly looking for the sensitivity number. It's quoted in the link you posted as 92dB, which is reasonably high. I very much doubt you'd need a fan.
What size is the room?
any suggestions about speaker protection and soft start boards
should I use them or not a good idea? Naim do not use them so there must be a reason?
should I use them or not a good idea? Naim do not use them so there must be a reason?
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