100 V is enough, i'm probably aiming for somewhere around 45-50 V for the main rail. Just thought because the main application for the kit seemed to be for the headphone amp, which won't need more then 25 V or something. The PSU BOM has a 25 V capacitor, maybe opc has planned a different setup for the amp.
Either way it should work out, capacitors are simple to come by i just prefer to know.
Either way it should work out, capacitors are simple to come by i just prefer to know.
well for custom trannies i always go to Richard Sumner (sumR) but i need to find out whats going on with the switcher before i consider that. you'd probably find Antek would do a custom spec job to
@QRikard: its a lm317/337 or lt108x/lt1033 based supply; the only thing stopping it being used for a 600v regulator would perhaps be track density. these regs only care about what max voltage they are expected to drop; in the case of lm317 the absolute max is 40V so you could have a 630v in 600v out reg. they don't know what ground is
@QRikard: its a lm317/337 or lt108x/lt1033 based supply; the only thing stopping it being used for a 600v regulator would perhaps be track density. these regs only care about what max voltage they are expected to drop; in the case of lm317 the absolute max is 40V so you could have a 630v in 600v out reg. they don't know what ground is
The psu board works with the higher voltage and so do the lm regulators, no problem there. I prefer to get a component kit as well and if that includes only the 25 V caps which is enough for the headphone amp i need to by separate caps like the ones opc linked (thanks hypertune for finding that post).
It isn't a problem to acquire the caps separately, i just want to know if i need to get those by myselves or if opc is kind enough to make a kit with the higher voltage parts as well.
It isn't a problem to acquire the caps separately, i just want to know if i need to get those by myselves or if opc is kind enough to make a kit with the higher voltage parts as well.
Would this case be enough for 70/60V supply or in other terms, for 225WRMS 8ohm/450WRMS 4ohm?
Pesante Dissipante 3U
Pesante Dissipante 3U
Is it the case that the low cost regulators like those proposed here for this use are designed to remove 100Hz or 120Hz and are not all that good at stopping higher frequency noise / ripple / spiking?
And is that why or partly why discrete regulators are said to sound better?
As far a +5V digital supply in CD players goes, I personally have heard big improvements with adding a simple series discrete regulator preceding a 7805.
Would such a device be a good idea here with this feed to the LME chip from after the SMPS?
I guess the only way is to try it and see, well, hear, and perhaps measure.
And is that why or partly why discrete regulators are said to sound better?
As far a +5V digital supply in CD players goes, I personally have heard big improvements with adding a simple series discrete regulator preceding a 7805.
Would such a device be a good idea here with this feed to the LME chip from after the SMPS?
I guess the only way is to try it and see, well, hear, and perhaps measure.
Hi Guys,
I'm working away during the evening getting everything put together, and I should be done pretty much all the building aspects by this weekend.
I'll get some pictures posted of the completed boards either tomorrow or the next day. I likely won't have test results until Monday or Tuesday, at which point it will be full speed ahead on payments and kit preparation. Orders that contain only boards will probably ship first, followed by kit orders shortly after.
qusp:
I sent you a PM. Sorry for the delay.
Emphrygian:
I'm not 100% certain about the implementation used on the SMPS, but from what I can tell, it looks like just a rectifier and some caps for the HV supply. It will be "regulated" by virtue of the other supply being regulated, but it will likely still contain a decent amount of switching noise.
Adding linear regs after the fact will help remove the harmonics of the switching fundamental that fall into the audio band, but the ripple rejection of the LM317 and LM337 is not very good at the actual switching frequency of the SMPS. If you want to address that, I would suggest an LC filter prior to the linear regulators, and after the output capacitor of the SMPS. That will help to suppress the fundamental, and the regs will help to further reduce noise in the audio band.
IanAS:
The simple LM317 and LM337 regulators are very effective across the entire audio band up to roughly 20kHz, but the ripple rejection capability above that really goes down hill. If the switcher operates at around 300-400kHz, then most of the fundamental would make it right through the regulators.
As I mentioned above, one solution is to add an additional LC filter to reduce the switching fundamental, and then use the LM regulators to reject ripple in the audio band.
Another solution is to use a very wide bandwidth regulator as you suggested, which would be more effective at reducing the noise form the SMPS all on its own. As to which is better, you'd really have to try both and decide.
homemodder:
The Alfet parts are actually diffused by Semelab, so the best thing to do is to get in touch with a local distributor for Semelab and see if they can get you what you need. Overall, they are pretty difficult to deal with.
Regards,
Owen
I'm working away during the evening getting everything put together, and I should be done pretty much all the building aspects by this weekend.
I'll get some pictures posted of the completed boards either tomorrow or the next day. I likely won't have test results until Monday or Tuesday, at which point it will be full speed ahead on payments and kit preparation. Orders that contain only boards will probably ship first, followed by kit orders shortly after.
qusp:
I sent you a PM. Sorry for the delay.
Emphrygian:
I'm not 100% certain about the implementation used on the SMPS, but from what I can tell, it looks like just a rectifier and some caps for the HV supply. It will be "regulated" by virtue of the other supply being regulated, but it will likely still contain a decent amount of switching noise.
Adding linear regs after the fact will help remove the harmonics of the switching fundamental that fall into the audio band, but the ripple rejection of the LM317 and LM337 is not very good at the actual switching frequency of the SMPS. If you want to address that, I would suggest an LC filter prior to the linear regulators, and after the output capacitor of the SMPS. That will help to suppress the fundamental, and the regs will help to further reduce noise in the audio band.
IanAS:
The simple LM317 and LM337 regulators are very effective across the entire audio band up to roughly 20kHz, but the ripple rejection capability above that really goes down hill. If the switcher operates at around 300-400kHz, then most of the fundamental would make it right through the regulators.
As I mentioned above, one solution is to add an additional LC filter to reduce the switching fundamental, and then use the LM regulators to reject ripple in the audio band.
Another solution is to use a very wide bandwidth regulator as you suggested, which would be more effective at reducing the noise form the SMPS all on its own. As to which is better, you'd really have to try both and decide.
homemodder:
The Alfet parts are actually diffused by Semelab, so the best thing to do is to get in touch with a local distributor for Semelab and see if they can get you what you need. Overall, they are pretty difficult to deal with.
Regards,
Owen