L'Amp: A simple SIT Amp

I have a question about inrush current.

I have been using choke version of L'amp (self biased), but every time it is powered up, I see the current meter goes up to 5A for a very short period. No speaker thump.

It has been this way for 2+ years, so I think it's probably not harmful, but I always wonder if any way to avoid this inrush current. I currently use 24V SMPS. If a thermistor would help, where I should put it?

Thank you.
for my audio, i always use toroid and cap bank which always secured by soft start board which never failed me. before using softstart, my fuse was always blown.

my experience with smps is only for pc gaming which only made my mcb trip. maybe you can just buy softstart board instead of thermistor only for feeling safe
 
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I have a question about inrush current.

I have been using choke version of L'amp (self biased), but every time it is powered up, I see the current meter goes up to 5A for a very short period. No speaker thump.

It has been this way for 2+ years, so I think it's probably not harmful, but I always wonder if any way to avoid this inrush current. I currently use 24V SMPS. If a thermistor would help, where I should put it?

Thank you.

If memory serves, the Tc of the bias supply I posted was a couple of ms.
 
replace 2sk82 with 2SK182ES

hi,
after read most of this thread, i decide to build the L'Amp.
i have pair of 2SK182ES.
can i build the same circuit recommended here with only the 2SK182ES?
i know that i probably need to tune the bias to the sweet spot.
thanks
 

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Go for it!
You should start the voltage with -10 and slowly going to something like -7.
You need a very good heatsink. BTW i use SiCs instead before i put on the 182ES because if something wrong, i don't like to break a 182ES...
resistor should be high power.
You are going to need a preamp with very low impedance and high voltage output.
I would also recommend:
- increase 10mF of out to 22mF
- put a resistor in source to ground of about 0.1 ohm, high power, i use arcos 100W, which are like a fortress.
 
yes start from -10 and then go slow... checking temperature and amperage. I would say to have about 2-3A and then later based on your heat sinks and PSU you can go higher. No need to go high voltage, avoid it. Go till 65V. For now, you can test without the zener protection, as long as you keep your input till 10V, which is very high
 
the setup is base on the L'Amp.
lm317 for the bias
3*regular lamp of 100W
change the PS to 60vdc

now its 60vdc with 0.5a and play fine, but way i cent increases the current?

edit:
strange: when i switch the lamp with 10ohm resistor, i can increase the current to 2.5A easy
 

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