I'm using two laptop brick for my ACA's. They were a lightweight chinese clones, no idea how well they are. With my 98dB full rangers I can hear constant pitch noise at zero volume, and its somewhat audible at three feet. I have Lambda JWS100-24 smps, Max 4.5A, adjustable voltage. Is it good idea to feed monoblocks with this?
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Starbender
If you have these to try I would hook one up to see how it works. I think Zen Mod told us you could use up to 24 volts supply for ACA. You could probably get by with a single one of these powering both circuits. They certainly look like they are heavy duty supplies. They didn't give an output noise figure in the spec sheet so only way to tell how silent it will be is to try it and see. Good luck!
Yes Mike, this one is heavy duty supply. I will try and report back. Let's hope this one is better than my cheepy laptop bricks.
We are using lots of industrial machinery, most of them has dc servo controllers and sensitive electronic circuits etc. All of them has some sort of Lambda smps. Don't know why..
We are using lots of industrial machinery, most of them has dc servo controllers and sensitive electronic circuits etc. All of them has some sort of Lambda smps. Don't know why..
Assuming you are using two of them is there any difference between the channels?
I have the ones that came with the kt and they are dead silent.
Does you power supply has 3-pin mains power input. It must have earth ground wire connected. I found in absence of that you may get pitch noise or buzzing sound from speakers.
Omishra, both bricks does not have ground wire. Only main&neutral. I removed some wall sockets at my house yesterday to check. Looks like there is no earth wire in any mains socket. I went to check building distribution panel. They bind neutral&earth together at the mains entrance!
ps: no other gear cause that kind of pitch noise. That's why I suspect about bricks..
Congratulations! So glad to hear that your new amps are working well.Report: removed laptop bricks and feed both mono blocks with lambda smps. Dead silence. I cannot even detect if mono blocks powered on or off. Not even hiss with 98dB full ranges..Case closed
I'm sure you are going to get much enjoyment from them.
Both sound great. The stock ACA kits can handle the extra heat just fine. See Loudthud's posts No. 1778 (reply to me) and post 713 of his graphs. With my system (single driver Fostex) the mod is the way to go.
Yes, voltage before output cap should be set to half of supply voltage. By that you allow amp to swing voltage to same maximum level on positive and negative half of the signal. If you would set it to other value than half, then either pos or neg half-wave couldn´t reach same max voltage swing as the other half-wave of the signal. Amplifier then couldn´t amplify both half-waves to same voltage potential. Hope my explanation helps .
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