Power consumption of PSA products


#1

I finally ordered my BHK 250 last week (very exciting!). While awaiting its arrival, I was reading the manual and saw that it uses 75W while in ‘Ready’ mode (p. iv of the manual). I assume that this is the same as ‘Standby’ mode referenced on p. 1 (if not, please clarify). This is the equivalent of leaving a 75W light bulb on all the time, which I would not consider as “using little power” (manual, p. 1). I understand the sonic benefits of having a standby mode; my current tube amp, which obviously cannot be left on all the time, takes two hours to sound its best. Leaving the power on might also lengthen the lifespan of some components, but I am not sure about that.

Right now I think I will turn off the back switch if I do not anticipate listening again within 24 hours, but I would appreciate comments about this. Is it a reasonable compromise? Any downside? How long does the BHK 250 take to sound good from a cold start?

The specs for the DS DAC and BHK Preamp show power consumption as 30W and 60W respectively, but give no indication of how much this is reduced when in standby mode. It would be helpful to have this information in order to use our equipment in an environmentally friendly way.


#2

I’ve been using my BHK 250 for about a year and have left it on most of the time. The only time I turn it off is when I leave the house for two days or more. I do that partly for energy savings but also for the paranoia factor, i.e., it could overheat/catch fire while I am gone. That paranoia is probably unfounded for the BHK, but is a carryover from when I had a tube amp and it was a legitimate concern. One of the reasons I went with the BHK is I have the amp on most of the day and with a tube amp that’s a lot of time on the tubes, uses lots of energy, and produces a lot of heat (which was good in the winter time). When PS Audio first started work on the “new amp” it was going to be N-Core based which sounded great to me, but alas it didn’t come to fruition. The BHK while not truly energy efficient (like N-Core) is reasonable compared to other audiophile amps. As far as the sound from cold turn on, I haven’t really listened closely. I have noticed some hardness initially, but when I return from being out for a few days one of the first things I do is turn the amp and the rest of the system on. I would suspect from cold start a minimum of two hours is required to get up to temperature and to sound good. I will add that I do put the amp in stand-by when I leave the house for more than a couple of hours and overnight. This saves some energy and tube life, and it only takes a 20-30 minutes to get best sound. One very minor downside to using the stand-by switch so often is the PS logo on the stand-by switch is just about completely worn off.


#3
pmotz said That paranoia is probably unfounded for the BHK, but is a carryover from when I had a tube amp and it was a legitimate concern.
Oh yeah. I forgot once to turn off my tube amp and went away for a few days. When I came back the tubes were redplated, but fortunately nothing had caught fire. Scary.
The BHK while not truly energy efficient (like N-Core) is reasonable compared to other audiophile amps.
Probably true, although I haven't researched this. My one point of comparison is the NAD C275BEE that I am currently using to drive the bass module of my speakers. It is rated at 150wpc, uses (according to the manual) 312W when playing music but <1W in Standby mode. Maybe that's why 75W for the BHK in standby seemed like a lot; I guess the BHK leaves more stuff energized than the NAD does in standby.
I would suspect from cold start a minimum of two hours is required to get up to temperature and to sound good.
Interesting; that's just what my current amps need.
it only takes a 20-30 minutes to get best sound. One very minor downside to using the stand-by switch so often is the PS logo on the stand-by switch is just about completely worn off.
Both good to know -- thanks!

#4

The NAD is probably a Class D amp, or some variation on that. The typical audiophile amp is Class A/B which will draw much more power in stand-by. For Class A/B I would think 50 -150 watts is a good guess for average stand-by power consumption. Pure Class A amps are even worse, some drawing hundreds of watts at idle.


#5

Just to make sure that we’re all using terms consistently, to me:

Standby = amp is not in use, a little power supplied to keep things warmed up or a light on the front panel
Idle = amp in use but no music playing

The BHK uses 175W at idle and 75 in ‘Ready’ (which I think = standby); my NAD uses 100W at idle and 1W at standby.

The NAD has (it says) “Class A Voltage Stages”; not entirely sure what that means.