Preventing Pops on Power-Up/Down: Monitor Controller?

[armevans]

Hi, SOS folks,

I'm a long-time reader but first-time poster. For years now, I've had a little studio space at home. In the past, I worked in a commercial recording facility and a college radio station, but these days, I primarily record myself and occasional friends. For many years now, the center of my recording universe has been an RME UFX (v1), but just this week, I upgraded to a Prism Sound Titan. There is a quite stark sonic difference between these two converters, and I am thrilled so far with the quality of the Prism's AD and DA conversion as well as its microphone and headphone amps. There were many features on the UFX that I didn't use, so I think the Prism overall offers a better match for my particular needs.

The only small frustration I've encountered thus far is that the RME had some circuitry that preventing pops/noise through the outputs in the event of a power cut, but the Prism does not (as far as I can tell). Right now, the Prism is in a rack with other gear, all connected to a power conditioner. My monitors (Neumann KH 80 DSPs) are on the desk, connected to a separate power strip behind the desk. With the RME, this system worked great—I left the monitors on constantly and could use the power switch on the rack to turn on and off the UFX as well as my other recording equipment.

With the Titan hooked up directly to the monitors, a noise occurs whenever the unit gets powered on. This noise is relatively small when the Titan is powered on from its own power button but is significantly louder when the unit is powered on via the power conditioner. Importantly, the Prism switches itself on whenever it detects power—as far as I can tell, there is no way to turn the power conditioner on without the Titan automatically turning itself on, even if it was powered off from the front-panel power button previously. Turning the Prism off from the front panel power button does not cause a pop in the monitors, but cutting power via the power conditioner's switch does create a significant pop.

I've heard the common adage that monitor speakers should be "last on/first off," but I'm struggling a bit to find the simplest solution for achieving that. The power strip the monitors are connected to is a bit difficult to get to, and I don't relish the idea of crawling under the desk multiple times every time I record. My monitors do have individual power switches on the back, but I worry that continually reaching behind them to power on and off will mean I am constantly shifting my monitor placement—not ideal.

I'm sure there are ways to get a power switch closer to hand, but I am wondering whether the simpler solution would be to use a monitor controller between the Titan and the monitors to have a "Mute" button close to hand. Is this how others (with Prism interfaces or other units that similarly make noise on start-up/shut down) are avoiding this problem? If so, does anyone have recommendations for a simple monitor controller that will not color the sound? I've been looking at the Drawmer CMC2, which seems to offer a compelling set of features for the price, but I'm hesitant to put anything in the chain that might sully the quality of the audio coming out of the Prism unit. I'd love to avoid a rackmount unit if I can—my rack space is limited, and if I'm spending money to solve this problem, I'd love to move the volume control closer to hand.

[Drew Stephenson]

I use a Drawmer CMC2 with KH80s and I've certainly not noticed any degradation of sound, but then I'm not feeding them with a Prism!
You might just need to try it and see.

[armevans]

I use a Drawmer CMC2 with KH80s and I've certainly not noticed any degradation of sound, but then I'm not feeding them with a Prism!
You might just need to try it and see.

Lovely! That's encouraging (and seems to be in line with the SOS review of the CMC2, which was fairly glowing). I'm not overly fussy (I don't think), but my last experience with an active monitor controller was a Presonus that sounded distinctly different than the DA that was feeding it, so I'd love to avoid that kind of situation.

I've read a few reports online of users having issues with the potentiometer on the Drawmer wearing out/getting noisy over time and requiring replacement. Is that something you've encountered with yours?

[ef37a]

First of all I find it astounding that a piece of gear costing well over £3,000 does not control the audio output no matter how it is powered up.

One solution perhaps is a wireless mains switch on the monitors thus they can be powered up last from a remote.

This problem crops up often enough that I would have thought some enterprising bod would have marketed a "speaker delay box"? Simply a good quality relay driven from say a 2-5 second delay. XLR/TRS in and out and a "screen diss" could be incorporated for good measure. Powered from a 5V wall rat. Those good people at Art Electronics looking in? There could even be an input to use the box for feedback kill in a talkback situation?

Dave.

[Drew Stephenson]

I've read a few reports online of users having issues with the potentiometer on the Drawmer wearing out/getting noisy over time and requiring replacement. Is that something you've encountered with yours?

Yes, there does seem to have been a batch / period where this was a problem, including mine. I dropped them an email and they sent a replacement that was a simple drop-in and the replacement has been fine since then (it's already lasted considerably longer than the first one).

[Wonks]

Unless you are in the US, most power conditioners do more harm than good. It shouldn't make the pop worse! If it's a UPS style conditioner it may not be giving out true sinusoidal power. Have you tried running the system without it for normal use?

[Hugh Robjohns]

First of all I find it astounding that a piece of gear costing well over £3,000 does not control the audio output no matter how it is powered up.

It sounds like it does — when operated by the front panel switch.

But it is a professional bit of gear and the designers probably assume the users will adhere to the monitors on last, off first practice — either manually or via a sequenced mains power switcher (which is a very common professional solution).

One solution perhaps is a wireless mains switch on the monitors thus they can be powered up last from a remote.

Yes, that's the easiest option. Cheap and effective. I'd power the two speakers from their own plug board fed from the remote switch. I've found the Energenie brand to be reliable, but there are plenty of others to choose from.

Or you could replace the 'power conditioner' with a mains switch panel so you could turn different subsets if gear on-off as desired and in an appropriate order and timing.

I'm also a big fan of analogue monitor controllers between converters and speakers, and there are plenty to choose from.

This problem crops up often enough that I would have thought some enterprising bod would have marketed a "speaker delay box"?

It's easier to switch the mains in the right order... and stuff already exists to do that.

[ef37a]

" This problem crops up often enough that I would have thought some enterprising bod would have marketed a "speaker delay box"?

It's easier to switch the mains in the right order... and stuff already exists to do that."

Well! You're no fun...at all!

Dave.

[Matt Houghton]

One solution perhaps is a wireless mains switch on the monitors thus they can be powered up last from a remote.

Yes, that's the easiest option. Cheap and effective. I'd power the two speakers from their own plug board fed from the remote switch. I've found the Energenie brand to be reliable, but there are plenty of others to choose from.

I went down this road about a decade ago, and never again — three failures in two years! By their very nature, these things tend to be placed in annoyingly inaccessible places (you wouldn't bother with them if you could reach, right?) so it's a pain to sort out if they go wrong.

Personally, I prefer rackmount IEC distros with front-panel on-off switches. An 8-way one needn't cost you more than £35 unless you want posh ones with separate fuses for each outlet accessible from the front. Not much in those to go wrong bar a blown fuse.

I guess not everyone uses 19-inch racks these days. The cheapo bodge-it option would be to bring a more conventional switched distro board to the back of your desk. A two-way one just for a pair of speakers should tuck nicely enough behind a computer screen or some such and cost peanuts...

Of course, neither these nor a monitor controller would solve the issue of popping during unexpected power cuts. I don't know enough about UPSs to make recommendations on that front, but am sure others do, and one that buys you the time to power down properly shouldn't cost the Earth.

[ef37a]

One solution perhaps is a wireless mains switch on the monitors thus they can be powered up last from a remote.

Yes, that's the easiest option. Cheap and effective. I'd power the two speakers from their own plug board fed from the remote switch. I've found the Energenie brand to be reliable, but there are plenty of others to choose from.

I went down this road about a decade ago, and never again — three failures in two years! By their very nature, these things tend to be placed in annoyingly inaccessible places (you wouldn't bother with them if you could reach, right?) so it's a pain to sort out if they go wrong.

Personally, I prefer rackmount IEC distros with front-panel on-off switches. An 8-way one needn't cost you more than £35 unless you want posh ones with separate fuses for each outlet accessible from the front. Not much in those to go wrong bar a blown fuse.

I guess not everyone uses 19-inch racks these days. The cheapo bodge-it option would be to bring a more conventional switched distro board to the back of your desk. A two-way one just for a pair of speakers should tuck nicely enough behind a computer screen or some such and cost peanuts...

Of course, neither these nor a monitor controller would solve the issue of popping during unexpected power cuts. I don't know enough about UPSs to make recommendations on that front, but am sure others do, and one that buys you the time to power down properly shouldn't cost the Earth.

You have been incredibly unlucky Matt. I have 3 wireless switched setups in my house. One for my Tannoys and 2 on some lights. They have been running for at least 2 years, the one on the speakers maybe over 3. Nay bother.

One safety feature is that they don't reset after a power cut and re "UPSesssss? I have to do another test on my new cheap one but will post that in the proper place. (little bit disappointed so far).

Dave.

[Arpangel]

But it is a professional bit of gear and the designers probably assume the users will adhere to the monitors on last, off first practice — either manually or via a sequenced mains power switcher (which is a very common professional solution).

Exactly this, there are a few things in my system, the interface included, that make quite large pops when when powered up or down, if I didn’t do monitors on last, off first, I'd be in trouble too as some of the pops are quite loud, but it's never bothered me because of what Hugh said, and I've always done this.

[Hugh Robjohns]

Three failures in a couple of years is unlucky, but there might be a reason.

A lot of line-lump power supplies, and switch-mode universal supplies inside equipment, can have HUGE switch-on surge currents. We're talking 50 or 60 amps quite commonly, but only for a fraction of a second — nowhere near long enough to blow a fuse, but enough to weld the contacts in a remote switch, particularly if the switch operates at the peak of the mains cycle.

I had exactly this problem with my rack-mount switch panel. Went through three or four switches in a year with welded contacts that wouldn't switch off.

In my case the main culprit was a particular line-lump supply to a digital meter. I changed the line-lump for a different brand which was better, but I still had problems occasionally.

And switching on several devices at the same time, all with SMPS switch-on surges, makes a switch failure even more likely, of course.

In the end I rebuilt my switch box to use miniature electronic relays controlled by the original mains switches. These relays automatically switch at the zero crossing which helps to control the switch on surge, too... and I've had no further problems.

[Sam Spoons]

My Quad 522 pops on switch on and splats on switch off regardless but not particularly loud. I usually switch the room on and off at the main power switch leaving the amp and a few bits of outboard switched on all the time. I do power off the mixer and computer before switching the main switch though and the mixer is configured to pull the main fader down at switch on.

[Matt Houghton]

My Quad 522 pops on switch on and splats on switch off regardless but not particularly loud.

I had an old Carver power amp that did that both on switch on and switch off. It was pretty loud. Never seemed to cause any damage to my speakers (Dynaudio BM15 back then) but it was bloody annoying nonetheless Happy to see the back of that one.

[Sam Spoons]

It's not too loud in this case and I have considerable history with the amp in that I bought it to use as my main PA power amp back in the '80s. I've used it in the studio since retiring it from that job many years ago and thanks to Foldy it's still going strong

[Arpangel]

My Quad 522 pops on switch on and splats on switch off regardless but not particularly loud. I usually switch the room on and off at the main power switch leaving the amp and a few bits of outboard switched on all the time. I do power off the mixer and computer before switching the main switch though and the mixer is configured to pull the main fader down at switch on.

My Quad 33 gives a nice reassuring vintage thud on power up, it’s very comforting.

[Sam Spoons]

Ah, if it ever starts to bother me (which it doesn't at the moment) I'll just remind myself that it's just a "nice reassuring vintage thud"

[ef37a]

Ah, if it ever starts to bother me (which it doesn't at the moment) I'll just remind myself that it's just a "nice reassuring vintage thud"

Ha! Just about the only slightly good thing about the standby switch fitted to almost every valve guitar amp is that going to standby before full off avoids a mild "scream" which a few amps make. This is only the case when the amp has a choke in the HT supply* because the component attempts to keep current constant even as it is decaying and you get some sort of "negative impedance" happening. I think it can be stopped with a CR 'snubber' across the choke but then you can bleed in noise.

*It might even only be peculiar to amps using valve rectifiers because they have a virtually infinite off resistance. To compound the felony, standby switches tend to destroy valve rectifiers...good riddance to both I say!

Dave.

[armevans]

Thanks all for the ideas! I should probably add that I am in the US, so I’m in a slightly different electrical situation regarding power conditioners and so on.

After chatting a bit with Frank at Prism, I think I’ve got the issue sorted.

He confirmed that the Titan does make a sound when powering up, but this is small enough that it shouldn’t practically pose any risk to speakers, nor is it a particular disruption in my situation. It makes a slightly louder sound when power is cut suddenly (as it is by a rackmount power conditioner), but this can be avoided by switching the unit to standby via the front-panel button before cutting power.

Funnily enough, I decided to actually read the manual for my Neumann KH80s, and it turns out that they actually have a 5-second delay built in specifically to account for this situation. So, I’ve opted to run a short power extension and power the monitors from the same rackmount power conditioner as the Titan. So long as I switch to standby before powering down the rack, this setup seems to sidestep any power on/off noises. So that’s $300 saved for the day.

[ef37a]

You are a Jonah Matt Houghton and have put a hex on me!

After years without trouble, early doors yesterday my Tannoys would not turn off with the remote. Too knackered at around 1am to sort it I pulled the plug and pitted.
This morning the battery checked fine at 11.97V but it turned out the 4pos' switch on the back of the remote was in the wrong shop. Now that is only about 1mm square and quite stiff so how it got shifted I cannot imagine other than someone sending out black magic thoughts!

Dave.

[Arpangel]

All these issues? well, what happened when I first moved into this house.
Pops and clicks on power up power down and just about anything else I did, I was also wondering why I was getting tingles from some items of gear, along with noise and hum on everything.
Believe it or not, I actually put up with all this and didn’t think anything of it, I think I mentioned it here at one point.
Then, I had cause to replace one of the sockets in this damp basement, and lo and behold, and a few AAARRRGGHHHHS!!! there it was, the whole basement ring main was wired up with 2 core 3 amp lighting flex.
I am lucky to be alive.

[Martin Walker]

...the whole basement ring main was wired up with 2 core 3 amp lighting flex.
I am lucky to be alive.

No wonder you adopted Arpangel as your forum name

[Hugh Robjohns]

The original feed to the basement was probably just for lighting. It wouldn't have been to modern spec, but it would have been a pragmatic solution in the days of incandescent bulbs in batten mounts.

...and then someone added a socket spur and decided to ignore that absent PE....