AC Power
I have a relatively nice system, but have done nothing with my AC power, with the exception of upgraded PC’s and a cheap iFi plug in power conditioner. My question is multi fold… do I need to do something, and if so what? Dedicated line (15A or 20?)? Quality power conditioner? Both? Which one first? How do you tell?
My system is a combination of HT & 2 channel & I tend to use both simultaneously as I like to watch sports while listening to music.
My amp is (I think) a relatively low draw… Moon 330A, Rythmik sub, BHK pre, Aurender, Qutest w/Sbooster, R11’s. No high power amps are in my future & never listen above 75db. I do currently plug my amp directly into the wall. All my wall warts are gone. For my HT, add a 75” Sony TV, Marantz 7015 AVR & a Klipsch sub (although at zero volume the AVR & sub should not come into play).
I am considering buying the Furman IT-Reference 15i or 20i first as they are well reviewed & are priced very well on Amazon ($1,400 / $1,900). Before I pull the trigger, should I go dedicated power & at what amperage (my nephew, an EE & audiophile thinks I am drawing no more than 5 amps) as that will dictate the Furman model?
Interesting, my nephew thinks neither are worth the investment. His statement: “Do you have appliances on the circuit now? What kind of interference can they inject?...voltage drops would come from current draws...which trip breakers.
Not steady 60hz a good power supply handles. So it all comes back to was the power supply engineer dropped on his head as a child.”
”Personally I think it’s something audio people do when they have run out of gear to buy.”
Any thoughts or recommendations would be appreciated. Thanks!
I really think buying the manufacturer's breaker is your best option but if anyone cares here's further discussion:
https://www.relectric.com/training/what-circuit-breakers-are-interchangeable/ |
I missed where you are ever getting close to 15A, let alone 20A. However, if you insist on a 20A unit, you’ll need to replace the plug. I use Leviton Hospital Grade plugs because their thick prongs are tighter but also the 90 degree angle takes less floor space and is less likely to wiggle out due to cable movement and leverage. Actually I only use a 15A conditioner, but still replaced the plug to keep the cable against the wall. This let me push a bass trap flat to the wall where the plug is. |
Generally speaking, @jea48 is right about not mixing breakers. Technically speaking, if you are mixing breaker brands the breaker has to be "listed" as being tested with the other maker’s panel. I believe this has to do with the maximum interrupt current of the individual vs. main breakers. In any event... Even if you do get a "listed" breaker, when you go to sell the inspector probably won’t bother to check if it’s listed or not and will flag it as something to be corrected. Just not worth the hassle or potential $10 in savings. So.... I generally also recommend sticking with the panel maker’s breakers even though you may find a listed breaker to use instead, and always stick to the NEC and local ordinances. If you are replacing a CAFCI or GFCI or combo breaker always replace it with the same feature set. (Exception is old AFCI are now called CAFCI and that is good!).. |
Maybe worth talking a little about "old school" regulators like Furman vs. PS Audio. Transformer based regulators have a fixed number of taps which are like holes on a belt. The conditioner constantly picks the best tap based on the output voltage. When that tap no longer is ideal it will switch. This means that adjustments are in about 5 volt increments either way. The advantage of this technology is efficiency and lack of switching noise in the AC signal. PS Audio uses Class D amplifiers to regenerate the output. Very expensive, very big and has switching noise on the output. Still, the benefits are a rock solid 120V +- about 1 Volt at all times as well as an unrivaled ability to deal with incoming AC noise and irregularities. |
I’m sorry @xenolith - but this is not necessarily true. Could you point me to an example? I’m not ragging on balanced, but the technology involved in creating balanced power is a separate technology from voltage regulation. Balanced power is achieved very simply with a transformer with near 1:1 windings. Usually a little more like 1:1.1 to allow for losses under load. This means the output voltage is always some ratio of input, and is therefore at the mercy of the input. BTW, the 220V you get from the power company is an example of balanced power. If you think balanced power always gives you a fixed voltage, well... there you go. Now, you CAN do both voltage regulation AND balanced power conditioning, but that doesn’t mean balanced power is always regulated. |
@amtprod - I would 100% avoid putting it near other linear piece of gear, like an amp or preamp, etc. Keep at least 4" above and below to ensure the magnetic field doesn’t couple to something else, maybe more. It IS safe to put directly on the floor though, maybe with a towel to avoid screws from scratching. I should also warn you that these sometimes do develop some mechanical hum. |
@mitch2 No, these units go on steep discounts routinely. Sometimes on Amazon, sometimes at Pro oriented stores so worth keeping an eye on them. You are correct that 15A (1800 VA) is basically overkill for most home systems. Furman makes so many models that it’s always good to check the specific feature set with Furman. The basic features you want are:
Usually those three come as a package in their pro or consumer models. These are some consumer oriented features:
So for me, SMP, LiFT, EVS and AR are features I really insist on having. The AR (automatic regulation) is the expensive part. Like balanced power, it takes a big internal transformer to work so adds a few hundred dollars to the price tag compared to say the basic Furman strip without. Furman DOES make an almost pure regulator without SMP, LiFT and EVS but more LEDs (HAH!) but uses old-school surge protection. The only advantage of that unit is that the LEDs constantly show you the incoming voltage. |
It may be worth noting that tightly regulating your AC may be more important to more classic designs. Gear with linear power supplies with DC rails that are always some proportion of the incoming AC line (i.e. linear amplifiers) will suffer more than more modern power supplies like in your TV or PC. |
I agree that this seems impossible. Your HVAC, electric range, water heater, etc. are all going to be 240V, and therefore on both legs. Small window AC units, hair dryers, toasters, fridge and microwave will be exceptions, but ideally your 120 V AC lines are balanced so that about the same amount of current flows on each leg, so not sure why or how you’d do this. Ahem... which is why I buck the trend and emphasize voltage regulation over isolation. If you can do both, even better. |
OP: Recently had a contractor plug a circular saw onto the same circuit and I watched the voltage after the AR, and it stayed rock solid. I could see the AR switching transformer taps every time the saw turned on and off, but the gear never felt it. That's how stable the voltage is. I've kept the combination ever since. Best, Erik |
OP: So sorry about the bad link, this one should be correct. 5W is sipping off the power. Furman makes a lot of models geared towards either home or professional users. If you like that unit, stick to it. :) I was just describing why my own gear is more focused on voltage regulation than isolation. Isolation focuses on noise. Regulation focuses on keeping the line voltage as close to ideal 120V as possible, and tries to compensate for over and under voltages as they occur. The unit you are suggesting has the most important features. SMP, LiFT and EVS. That will keep your gear noise free and healthy for a long time. |
Hi OP: You are getting good advice. My observations, living in apartments and now a detached home is that most significant voltage fluctuations come from seasonal variations as well as major appliances (HVAC, dryer, etc.). It is _very_ rare to see a home user’s equipment draw enough to cause significant sag, but it does happen with mega heavy Class A amps. I base this on having a Furman with voltage output and using plug in voltage monitors. The dedicated circuit may help reduce noise from other devices on the same circuit, such as for instance PCs, LED light strips, etc. Based on this my advice is:
Personally I go with regulation over isolation, so this is a unit I really like. |
