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Deleted member 148505
Power supply is connex SMPS300RS with upgraded caps, adjusted to 36V (removed trimpot and soldered 1K + 150 ohm 0805 resistors)
The other module is just a softstart converted into an AC switch. The red block is an onboard PCB AC transformer. Front panel switch turns the relay on-off.
If I have an smps with an on-off sense switch, or if the front panel mains switch is rated by at least 220V 5A, the other module is not needed.
Regards,
Lester
The other module is just a softstart converted into an AC switch. The red block is an onboard PCB AC transformer. Front panel switch turns the relay on-off.
If I have an smps with an on-off sense switch, or if the front panel mains switch is rated by at least 220V 5A, the other module is not needed.
Regards,
Lester
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Deleted member 148505
Are you using balanced connection? I can't detect constrained sound on balanced + PFFB combo, though I will compare this weekend just to make sure.
Could we get some results at 5 kHz as well? Intermodulation testing would be much appreciated too.
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Deleted member 148505
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Deleted member 148505
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Deleted member 148505
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Deleted member 148505
You can try disconnecting the fan. If it doesn't like not having a fan, you can replace with a dummy load. Just make sure you check the temps during loud/low-crest-factor music to make sure it's not getting too hot. If it does get too hot, replace the fan with a 80/92/120 mm silent PC-style fan, e.g. Noctua.
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Deleted member 148505
Meanwell SE-450-48 also has remote sensing function. Try to connect it as specified on this link before you remove the fan and top cover. Remote Sensing - MEAN WELL Direct
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Thanks for the advice.
BTW, meanwell application engineer says the fan should go off. I called the local distrobutor service and they claim they checked another new PS of the exact same model and the fan always on. Go figure... Unfortunately there is no schematic diagram available and I'm not going to spend my time on reverse engineering / troubleshooting the issue. It's not that important.
I disconnected the fan and will watch the hot areas during operation. In case needed, I will add an external fan considering the chassis structure (once I have a chassis
).
Regarding the remote sense, I checked and there are internal 10 Ohm resistors between the outputs and the sense conenctions, so I assume direct connection will not change much.
BTW, meanwell application engineer says the fan should go off. I called the local distrobutor service and they claim they checked another new PS of the exact same model and the fan always on. Go figure... Unfortunately there is no schematic diagram available and I'm not going to spend my time on reverse engineering / troubleshooting the issue. It's not that important.
I disconnected the fan and will watch the hot areas during operation. In case needed, I will add an external fan considering the chassis structure (once I have a chassis
).Regarding the remote sense, I checked and there are internal 10 Ohm resistors between the outputs and the sense conenctions, so I assume direct connection will not change much.
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Deleted member 148505
With my latest build, only the smps300rs, ac terminal mains earth, and XLR shield is connected to the chassis GND. XLR pins 123 are floating. Sylph-d200 is also floating. I can't see any mains hum in my RTA results with that configuration. Though here in the Philippines, most residential homes don't use gnd earth connection, 2 prong outlet is common, so I haven't tested it with the earth connection lol
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All comercial amplifiers I ever saw were double insulated (w/o mains ground wire) and the chassis is connected to the signal ground.
In my case, as the PS needs the earch ground for the EMI filter, it does not make sense to feed the PS w/o mains ground. I see the following options:
1. Connecting the chassis to the mains ground (just mounting the PS on the chassis will do it) and float the input RCAs
2. floating the PS from the chassis by using some plastic fasteners, connecting the DC ground to the chassis and avoid floating the RCA connectors.
3. connect the signal ground to the mains ground at one single point (screw on the chassis). It can be a direct connection or through resistor/inductor/capacitor.
Which option makses more sense?
In my case, as the PS needs the earch ground for the EMI filter, it does not make sense to feed the PS w/o mains ground. I see the following options:
1. Connecting the chassis to the mains ground (just mounting the PS on the chassis will do it) and float the input RCAs
2. floating the PS from the chassis by using some plastic fasteners, connecting the DC ground to the chassis and avoid floating the RCA connectors.
3. connect the signal ground to the mains ground at one single point (screw on the chassis). It can be a direct connection or through resistor/inductor/capacitor.
Which option makses more sense?
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Deleted member 148505
Hmm either a combination of 1 and 3, or #2 implementation but make it double insulated, float all parts like the chassis do not exist, use 8mm plastic standoffs and place kapton tape under modules.
This is what I'll do with my Sylph-D200 build:
Use IEC connector for mains wire, then connect the IEC's earth to chassis. If the chassis is anodized, sand it off for better connection.
Same with the switching power supply, connect the earth to chassis, I think ground loop protection is built-in on the Mean well supply.
Make the Sylph-D200 float, for the RCA connectors, insulate them from the chassis, and connect a capacitor on each signal ground of the RCA terminals to the chassis.
Not earth the -V of the Mean Well.
This is what I'll do with my Sylph-D200 build:
Use IEC connector for mains wire, then connect the IEC's earth to chassis. If the chassis is anodized, sand it off for better connection.
Same with the switching power supply, connect the earth to chassis, I think ground loop protection is built-in on the Mean well supply.
Make the Sylph-D200 float, for the RCA connectors, insulate them from the chassis, and connect a capacitor on each signal ground of the RCA terminals to the chassis.
Not earth the -V of the Mean Well.
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Deleted member 148505
I thought that by not connecting the remote sense, it messes with load current detection of the power supply, that's why the fan doesn't want to turn off. But maybe I'm wrong.
Thanks for the advice.
BTW, meanwell application engineer says the fan should go off. I called the local distrobutor service and they claim they checked another new PS of the exact same model and the fan always on. Go figure... Unfortunately there is no schematic diagram available and I'm not going to spend my time on reverse engineering / troubleshooting the issue. It's not that important.
I disconnected the fan and will watch the hot areas during operation. In case needed, I will add an external fan considering the chassis structure (once I have a chassis
Regarding the remote sense, I checked and there are internal 10 Ohm resistors between the outputs and the sense conenctions, so I assume direct connection will not change much.