I have a VocoPro Feather Amp FA-500 board, which I bought for its 100% genuine IcePower 125ASX2 board + case + connectors, and because it's been on a good sale at $100 (+ shipping + import duty ended up $175). The official IcePower board itself would be 200+ GBP in Europe.
Out of the box, it sounded downright bad, but it's because of a really bad input buffer board they've included. After using it for a while I finally got to open it and remove everything non-IcePower related (input board, LED, power switch circuit + the fan).
I bought the Ghent Audio cable kit and directly connected RCA sockets to the board, now it's exactly like how a Ghent Audio kit would be. Except for the mains.
I'm puzzled about mains, here are my points (sorry if they are not logical, that's the reason I'm asking here):
- I heard that an electric appliance is either double insulated or single insulated
- Single insulated == 3 plug socket, Double insulated == 2 plug socket or these are different things?
- Single insulated == metal case, double insulated = plastic case?
- The VocoPro amp has 2 plug socket and a full metal body
- Every DIY Class D build I see (Ghent Audio, Nord, Apollon, Audiophonics) uses 3 plug sockets, connecting the earth pin to the case in a sanded point.
- VocoPro is FCC certified ("This product has been tested and found to comply with the requirements listed in FCC Regulations, Part 15 for Class "B" digital devices.")
- The VocoPro has the heatsink around some components (transformers?) directly touching the outside of the case
- The IcePower board in the VocoPro is "suspended" by tiny metal L shaped holders connected to the case by metal screws
Now here is my most puzzling part: when I opened the device, the power switch circuit was extremely fiddle, two legs were directly soldered in a 90-degree angle, just over a tiny point, without any wire. In the datasheet, this board might use up to 6.75 Amps, which I'd guess requires way bigger wires than just soldering two tiny legs in a 90 degree joint. Nevertheless, I've removed the switching circuit and soldered the mains socket's legs directly to JST mains cable. It works now, but there is no way to switch off the amp now, I have to plug the cable every time.
My questions:
- Please help me find the logic between the points I've raised above. We are not talking about a cheap Aliexpress device here, but one from a known Californian company, with FCC certifications, assembled in Taiwan.
- How should I implement the mains connection and the mains switching of the device?
- I'm leaning towards using a 3 plug socket (requires cutting the metal plate somehow) and connecting the earth pin to a sanded part of the metal case. But this is not how this device was designed to operate. Wouldn't this cause any problems?
- How do you add a switch to a device? For example, I like the ones at the front, do I have to bring the live wire to a switch at the front and then back to the power socket? What kind of switch can I use which doesn't look bad (probably metal), yet is safe to be connected to the front / touched by a user?
- Does connecting the case to the earth affect any of the sockets? I'm using RCA sockets where both 0 and live are isolated from the case, is this by design? Would balanced XLR sockets require connecting the 0 pin to the case?
Out of the box, it sounded downright bad, but it's because of a really bad input buffer board they've included. After using it for a while I finally got to open it and remove everything non-IcePower related (input board, LED, power switch circuit + the fan).
I bought the Ghent Audio cable kit and directly connected RCA sockets to the board, now it's exactly like how a Ghent Audio kit would be. Except for the mains.
I'm puzzled about mains, here are my points (sorry if they are not logical, that's the reason I'm asking here):
- I heard that an electric appliance is either double insulated or single insulated
- Single insulated == 3 plug socket, Double insulated == 2 plug socket or these are different things?
- Single insulated == metal case, double insulated = plastic case?
- The VocoPro amp has 2 plug socket and a full metal body
- Every DIY Class D build I see (Ghent Audio, Nord, Apollon, Audiophonics) uses 3 plug sockets, connecting the earth pin to the case in a sanded point.
- VocoPro is FCC certified ("This product has been tested and found to comply with the requirements listed in FCC Regulations, Part 15 for Class "B" digital devices.")
- The VocoPro has the heatsink around some components (transformers?) directly touching the outside of the case
- The IcePower board in the VocoPro is "suspended" by tiny metal L shaped holders connected to the case by metal screws
Now here is my most puzzling part: when I opened the device, the power switch circuit was extremely fiddle, two legs were directly soldered in a 90-degree angle, just over a tiny point, without any wire. In the datasheet, this board might use up to 6.75 Amps, which I'd guess requires way bigger wires than just soldering two tiny legs in a 90 degree joint. Nevertheless, I've removed the switching circuit and soldered the mains socket's legs directly to JST mains cable. It works now, but there is no way to switch off the amp now, I have to plug the cable every time.
My questions:
- Please help me find the logic between the points I've raised above. We are not talking about a cheap Aliexpress device here, but one from a known Californian company, with FCC certifications, assembled in Taiwan.
- How should I implement the mains connection and the mains switching of the device?
- I'm leaning towards using a 3 plug socket (requires cutting the metal plate somehow) and connecting the earth pin to a sanded part of the metal case. But this is not how this device was designed to operate. Wouldn't this cause any problems?
- How do you add a switch to a device? For example, I like the ones at the front, do I have to bring the live wire to a switch at the front and then back to the power socket? What kind of switch can I use which doesn't look bad (probably metal), yet is safe to be connected to the front / touched by a user?
- Does connecting the case to the earth affect any of the sockets? I'm using RCA sockets where both 0 and live are isolated from the case, is this by design? Would balanced XLR sockets require connecting the 0 pin to the case?
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