Thanks for the reply. I don't have an option to connect directly to the DC of the amp at the moment.
@RickRay Thanks for the reply. I was contemplating using a Double conversion UPS. Essentially it is regenerating the AC signal at all times so always online. With or without the mains supply available.
After contemplating a static stabiliser+interactive UPS which would roughly cost double, I decided to take a chance with online UPS. Got an Eaton 9px 3KV model after testing the inrush current. Has over and under voltage protection with overload bypass. Haven't heard any audible hums or noise. Sounds cleaner and so far didn't notice any problems with transients or dynamics. The voltage is maintained at a constant 230V.
For audio quality, the words one wants are "Online Double-Conversion Pure sine wave" UPS. These are heavy and expensive, and if used for audio, some mild modifications are needed, such as changing out the internal fans with quiet ones (recommend fan controllers at the time) and changing out the flimsy AC outlets with more solid ones.
I have been using a modified one for years (Libert/Vertiv) in my main audio system where it has sounded quite a bit better than massive isolation transformers, balanced power conditioenrs, etc.
I have been using a modified one for years (Libert/Vertiv) in my main audio system where it has sounded quite a bit better than massive isolation transformers, balanced power conditioenrs, etc.
I agree about the fan noise. It is definitely not the advertised range of 35 to 50 db @1m across various brands and models. Even without load I can record around 55db from a distance of 5m. As @drjlo mentioned about changing fans, that is one option. The other is what I did, put in a completely separate room or location of the house isolated.
About 10 years ago I installed a dedicated power line for my hifi. I followed this up with I adding an 8kVA balanced power transformer which I found to be beneficial. I have recently been experimenting with an APC SURT8000XLI. This either replaced the balanced power transformer, or was added to the mains chain before the balanced power transformer. I preferred the sound with both inline so that's where I stand at the moment. It's now installed in the basement below the listening room (noisy fans!).
The UPS is an online, double-conversion sine wave and my reason for including it in the chain was because we have occasional brown outs for a second or two...but also, I wondered whether it would function as a "giant capacitor" bank very close to the load. Pure conjecture on my part but it does sound (a little) better with it inline. I inherited the unit (which was being decommissioned) and I'm not sure I'd say the improvement would be worth the money if I had to pay for it but it has opened up an interesting avenue of investigation.
I am finding it very hard to identify which UPSs might provide further improvement from looking at the data sheets. Clearly the ability to deal with instantaneous current requirements will be a benefit but I can't see this listed in the average UPS sheet...any thoughts?
The UPS is an online, double-conversion sine wave and my reason for including it in the chain was because we have occasional brown outs for a second or two...but also, I wondered whether it would function as a "giant capacitor" bank very close to the load. Pure conjecture on my part but it does sound (a little) better with it inline. I inherited the unit (which was being decommissioned) and I'm not sure I'd say the improvement would be worth the money if I had to pay for it but it has opened up an interesting avenue of investigation.
I am finding it very hard to identify which UPSs might provide further improvement from looking at the data sheets. Clearly the ability to deal with instantaneous current requirements will be a benefit but I can't see this listed in the average UPS sheet...any thoughts?
"It's now installed in the basement below the listening room (noisy fans!)"
This is the main problem with these on-line double-conversion units, and the problem gets much louder as you go to the large, industrial type units like yours, which likely has multiple fans. This is pity because I find these units to sound best close to the audio components feeding them directly via high-quality power cabling.
Next time you have to service them for some reason, perhaps you can change out the fans for fresh, super-quiet fans, which in those APC SURT units should be (multiple) 120 mm DC fans (pin 1 Positive, pin 3 Negative, pin 2 unconnected, ). 120 mm quiet fans from Noctua, Nexus, etc would be much quieter. I even installed a fan speed controller inside so the quiet fans behave even quieter.
This is the main problem with these on-line double-conversion units, and the problem gets much louder as you go to the large, industrial type units like yours, which likely has multiple fans. This is pity because I find these units to sound best close to the audio components feeding them directly via high-quality power cabling.
Next time you have to service them for some reason, perhaps you can change out the fans for fresh, super-quiet fans, which in those APC SURT units should be (multiple) 120 mm DC fans (pin 1 Positive, pin 3 Negative, pin 2 unconnected, ). 120 mm quiet fans from Noctua, Nexus, etc would be much quieter. I even installed a fan speed controller inside so the quiet fans behave even quieter.
