So, I'm working on a desktop headphone amp/preamp combination in a single box. In the past with similar devices, I've used an O2-style voltage doubler with a centre tap, powered off a single AC input.
Yesterday, I was browsing RS, and came across a really nice looking part that I thought could simplify and generally improve my design. 70051K | 2 Output Toroidal Transformer, 15VA, 2 x 9V ac | Nuvotem Talema I haven't decided on a particular power/voltage rating yet, but they all follow a similar footprint and size. My intention is to mount this transformer on the same PCB as the rest of the amp.
The case I was looking at using would fit the whole power supply internally rather than an external AC wall wart. my biggest concern is the potential for hum pickup or other interference from having AC current flowing so near to my amp circuitry. I feel the PSU could actually be better performing than the O2 style one, because it would use full-wave rectification rather than half wave - which also would reduce the physical size (and value) of the main power supply caps. This would lower cost, and be easier to physically work with inside the enclosure I want to use.
I guess my question is, with proper design, do I need to worry about interference/noise from having a transformer mounted on my main PCB? Are there any obvious pitfalls that I should try to avoid with this setup? Are there any tricks to reduce noise from a transformer in the same enclosure as the active parts of the amp? I thought maybe isolating the board using a gap in the ground plane, and perhaps some sort of metal shield between the PSU/amp sections could help with this.
Oh, one more thing, does anyone have a datasheet for these transformers? I'd like to get some more info than RS seems to have on the page, but there's no datasheet easily available as far as I can tell.
Yesterday, I was browsing RS, and came across a really nice looking part that I thought could simplify and generally improve my design. 70051K | 2 Output Toroidal Transformer, 15VA, 2 x 9V ac | Nuvotem Talema I haven't decided on a particular power/voltage rating yet, but they all follow a similar footprint and size. My intention is to mount this transformer on the same PCB as the rest of the amp.
The case I was looking at using would fit the whole power supply internally rather than an external AC wall wart. my biggest concern is the potential for hum pickup or other interference from having AC current flowing so near to my amp circuitry. I feel the PSU could actually be better performing than the O2 style one, because it would use full-wave rectification rather than half wave - which also would reduce the physical size (and value) of the main power supply caps. This would lower cost, and be easier to physically work with inside the enclosure I want to use.
I guess my question is, with proper design, do I need to worry about interference/noise from having a transformer mounted on my main PCB? Are there any obvious pitfalls that I should try to avoid with this setup? Are there any tricks to reduce noise from a transformer in the same enclosure as the active parts of the amp? I thought maybe isolating the board using a gap in the ground plane, and perhaps some sort of metal shield between the PSU/amp sections could help with this.
Oh, one more thing, does anyone have a datasheet for these transformers? I'd like to get some more info than RS seems to have on the page, but there's no datasheet easily available as far as I can tell.
