Someone asked why an isolation transformer could be beneficial. Its more a question of "how could it NOT be beneficial". They are almost always used in sensitive labs.
The electrical engineering answer is noise reduction on the input power. Isolation transformers are progressively more lossy as you diverge from their design frequency, which is 60 Hz. SO in theory power stays, noise is attenuated. My (doubtful) guess on why (other iso transformers) didn’t work well with big amps plugged in is that they restricted power delivery (instantaneous). I find this strange for two reasons:
1. I have used them with GREAT results (typically 2-3 kVA commercial units though that cost >>>$1000)2. As well designed power supply pulls DC transients from storage capacitors, not the wall> for example past designs of mine that can delver > 40A instantaneously (to the speakers) operate just fine with a 3A slow blow fuse on the AC mains. Do the math.
I do ack that you can get a lot more out of them by plugging ALL your low power devices into them. Just plug the current - hungry power amps into the wall. A typical DAC or preamp (high end variety) draws less than 30W, many less. Tubes, ok ,more (but not that much more).
I run both an ISO transformer and a custom made power filter with chokes and shunt capacitors. I need to make one for my "B" (living room) system.
G
The electrical engineering answer is noise reduction on the input power. Isolation transformers are progressively more lossy as you diverge from their design frequency, which is 60 Hz. SO in theory power stays, noise is attenuated. My (doubtful) guess on why (other iso transformers) didn’t work well with big amps plugged in is that they restricted power delivery (instantaneous). I find this strange for two reasons:
1. I have used them with GREAT results (typically 2-3 kVA commercial units though that cost >>>$1000)2. As well designed power supply pulls DC transients from storage capacitors, not the wall> for example past designs of mine that can delver > 40A instantaneously (to the speakers) operate just fine with a 3A slow blow fuse on the AC mains. Do the math.
I do ack that you can get a lot more out of them by plugging ALL your low power devices into them. Just plug the current - hungry power amps into the wall. A typical DAC or preamp (high end variety) draws less than 30W, many less. Tubes, ok ,more (but not that much more).
I run both an ISO transformer and a custom made power filter with chokes and shunt capacitors. I need to make one for my "B" (living room) system.
G