Hello, guys.
Recently bought three PSC2.400 plateamps for my LCR speakers. One of them is a 400d, but that is not important here.
I have pretty sensitive DIY speakers (102-103dB/2.83V) and I have severe hiss and noise in all three speakers. The noise is easily audible in my listening position. The noise is there even with nothing connected at the input, and even with the input shorted, so I'm assuming this is coming from the amp itself somewhere. Turning the amp volume down helps slightly, but even muting the amps don't remove the hiss, only reduce it. Even muted the noise is audible in the MLP.
The amps are mounted outside the speakers. 1,5m powercord, and less than a meter speakerwire. I run XLR interconnects from my pre, but that is irrelevant as the noise is there even without the source connected.
Any tips?
Hypex customer support told me to sod off, the noise is normal. I beg to differ. The amps all sound great apart from this. I suspect the DSP board is just very noisy, but I can't confirm it as the UcD400 modules are all mounted to the DSP and the 36-pin arrangement makes disassembly and testing difficult.
Recently bought three PSC2.400 plateamps for my LCR speakers. One of them is a 400d, but that is not important here.
I have pretty sensitive DIY speakers (102-103dB/2.83V) and I have severe hiss and noise in all three speakers. The noise is easily audible in my listening position. The noise is there even with nothing connected at the input, and even with the input shorted, so I'm assuming this is coming from the amp itself somewhere. Turning the amp volume down helps slightly, but even muting the amps don't remove the hiss, only reduce it. Even muted the noise is audible in the MLP.
The amps are mounted outside the speakers. 1,5m powercord, and less than a meter speakerwire. I run XLR interconnects from my pre, but that is irrelevant as the noise is there even without the source connected.
Any tips?
Hypex customer support told me to sod off, the noise is normal. I beg to differ. The amps all sound great apart from this. I suspect the DSP board is just very noisy, but I can't confirm it as the UcD400 modules are all mounted to the DSP and the 36-pin arrangement makes disassembly and testing difficult.
This is the limitation of the used DSP with build in A/D and D/A converters. If you use the PSC2.400D version with the digital input AND drive them with a digital signal the noise will be lower. You are having a pretty high efficiency loudspeaker.....
I am aware that my speakers are very efficient, and I am prepared to accept a little hiss in them of course. Digital is not an option, as there are no processor on the market that has digital pre-outs that I am aware of. I have tried the AES inputs on my single 'D' amp, and the noise is very slightly less, but still very audible in my listening position.
The S/N numbers and Dynamic range figures of your DSP board is noteably worse than those of other cheap DSP boards like MiniDSP. Now, that could be more honest specs from your part and I will not hold it against you at all until I have tested the MiniDSP in my setup.
The S/N numbers and Dynamic range figures of your DSP board is noteably worse than those of other cheap DSP boards like MiniDSP. Now, that could be more honest specs from your part and I will not hold it against you at all until I have tested the MiniDSP in my setup.
I doub't the MiniDSP will have a lower noise level, as far as I know they use the same DSP with build in A/D and D/A converter.... We have paralelled some inputs and outputs to reduce the noise. There is a trick possible to reduce the gain of the HF section and to reduce the noise. Advisable to have experience in SMD....please contact support at hypex dot nl.
I have, and I'm not comfortable with SMD soldering, so I won't do that mod. I might see if I can get someone more comfortable doing that mod. Besides, the non "D" amps are Rev2 boards and don't have the HW gain mod available.
I might try to sell the amps and get some UcD and SMPS modules and try with some other DSP or even passive crossovers. Normal speakers don't have this issue. I have a pair of Klipsch RF-82 for rears, and even though they are not much lower in stated sensitivity the noise is barely audible at 1m from the horn in those.
Thank you for the help, Jan-Peter. It's pretty much a carbon copy of the advice I got from Matthijs over at CS.
I might try to sell the amps and get some UcD and SMPS modules and try with some other DSP or even passive crossovers. Normal speakers don't have this issue. I have a pair of Klipsch RF-82 for rears, and even though they are not much lower in stated sensitivity the noise is barely audible at 1m from the horn in those.
Thank you for the help, Jan-Peter. It's pretty much a carbon copy of the advice I got from Matthijs over at CS.
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ohh, it open... ok
At this time, you would really need scope to measure some of the things.
I mean you can try, but it will take work
One idea would be to try only the amp, out of this pack, different supply,...
I know speakers are damn, good, but then again why not, I would like all of them to be like it in the first place
At this time, you would really need scope to measure some of the things.
I mean you can try, but it will take work
One idea would be to try only the amp, out of this pack, different supply,...
I know speakers are damn, good, but then again why not, I would like all of them to be like it in the first place
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