Powering up and down equipment

[platesrecords]

Hi-

I can imagine there are a lot of conflicting theories here; but what is the consensus on powering down lathes/vintage audio/electronic gear? Do you leave them on always? Power down every evening? Reasons?

I have heard mixed messages about this and can't decide which is best for my equipment. I have noticed that sometimes the lathe and/or the capps computer must be powered down or powered up in certain order otherwise they will behave weirdly and not function properly. This also seems to affect the tacho motor that drives the feed screw.

I am using a 501 scully lathe, modded, with capps vari pitch computer [operated fixed pitch]

Thanks!

Nick

[fredbissnette]

when i worked in pro audio we would always power up the preamp devices like mixers,processing and anything directly connected to instruments first(with all gains down) then power up the amplifiers connected to the speakers(drivers) then bring up the gain on the signal and to power down we do the reverse we bring down the gain on the preamp devices and then turn off the amps and then we can turn off the mixers etc otherwise you get a big pop in the system and break drivers.

[platesrecords]

Thanks Fred, useful to know

I usually do a similar thing but it is based on common sense rather than practical knowledge...! I was mostly wondering about powering on and off lathes and their PSUs. I guess because I've heard 'always leave it on' by many respectable people and also 'power it down' by the same token.

Hard to tell, there seems to be some logical sense in keeping old machinery powered up I guess, but I wonder whether having it on all day and powering down at night would suffice.

Cheers for your help !

Nick

[fredbissnette]

i think powering down is smart and easier on the electronics, things like capacitors wear over time and the less they are on the better plus youll save $ on power hehe

[sameal]

I have heard all manner of arguments from one side to the other, and my personal opinion is:

If it's gonna blow up, it was gonna blow up.

Setting aside the obvious pops over the playback system and such, and no power for years, there's no way to know what's gonna have a problem. Use it to the maximum everyday and don't think about it. Do periodic check ups on the equipment if you can and have an emergency fund and tech.

[mossboss]

Let's see if this makes sense
We have a few thousand components say on a cutting lathe or another piece of equipment for that matter
We turn on the juice so as to cut a plate play something whatever
What happens?
Juice flows through the various components which make up the psu system and subsystem
At very best cases one may get say 50-60% efficiency from input to output
What happens to the rest?
Turns into heat. Simple
So all components will have some resistance to current flow either deliberate or naturally
The component will expand due to heat generated than settle down to its new "size"
It will remain as such until powered down then shrink back to its original size
Have a think about it!
Expand contract and again! repetition on off this will ultimately result in failed components
As an example, in particular with early solid state stuff, say a 3 lead transistor
I bit of silicon or germanium is generally fusion welded on the metal base which is a gold plated steel, the back of the wafer has a layer of gold on it the metal part is heated to the point were the gold melts than the wafer is placed on it which fuses it to it
Than 2 flying leads are welded on the wafer, emitter and collector, the lead on the base is generally spot welded on the metal "base"
The flying leads are than welded into the two posts, which is where we solder it,
Not sure now days but in early days these were insulated from the metal base with a bit of glass, once the leads are soldered on the wafer and the posts A drop of glue is added, pre silicon Days so as to stop the leads moving, the component is than capped of and tested, if it passes it gets packed sold etc
So we have, steel, a bit of a wafer from silicon or germanium gold glass and glue
None of the above has similar expansion contraction characteristics
Ultimately the on off heat cool action will cause failure in any component it is a simple case of physics nothing to do with design
The lesson was learned many years ago when we had tubes, naval manuals to radio operators provide a very extensive set of instructions how to treat vacuum tubes in ships which found its way to radio stations etc etc
Well, the most important bit was to never turn them off, power down the filament so as to keep them tubes warm, turn off the high voltage but not the filaments,
Want long life from tubes? it is imperative to never turn vacuum tubes off if you want them to last forever, and they will
The point is this,
Unless equipment is to be powered down for any extended period of time leave them ON
By the way capacitors will last far longer under power, ask any Pro who has anything to do with vintage gear
They will never power up equipment which has been sitting around for a while straight up
It is done slowly so as to settle down components, mainly the capacitors in the system, generally it is done with a variac from say 10-100% power over a period of a day or two
The gear will be left on for a further period of time to drive off any moisture that will most likely be there, assuming that it has stayed in one piece, ha,
So I leave you with the above thoughts which are based on personal experience been involved in the industry in its early days more than 45 years ago.
By the way, further input on the subject from the posters here be nice

Best

[sameal]

Im not an industry veteran, so take my advice with that grain of salt. Im also not saying im right, it's just my opinion i've adopted.

I have way to much gear to have it all powered on at once, so i only power on what i need when i need it. But i also have purchased 90% of my gear with some issue and fixed it. I think almost everything i own has had a problem at some point.

And lately, i haven't had much time for my studio. I couldn't imagine keeping it on 24/7. I primarily only use my studio for me now.

I would definitely agree with the theory that components get stressed the most on power up and power down. I think constant controlled temperature also helps extend gear life.

But also if you have a few racks of gear on at all times, and one developes a problem without your knowledge, it could do a lot of damage before you find it. If you snap it on daily and it pops, you found the problem immediately. You might even get lucky and power it down before it gets cooked.

Other then power consumption, and having gear on through power issues and storms without proper protection, those are about the only arguments i can think of right now to keep gear powered down until you need it.

[platesrecords]

Let's see if this makes sense
We have a few thousand components say on a cutting lathe or another piece of equipment for that matter
We turn on the juice so as to cut a plate play something whatever
What happens?
Juice flows through the various components which make up the psu system and subsystem
At very best cases one may get say 50-60% efficiency from input to output
What happens to the rest?
Turns into heat. Simple
So all components will have some resistance to current flow either deliberate or naturally
The component will expand due to heat generated than settle down to its new "size"
It will remain as such until powered down then shrink back to its original size
Have a think about it!

Best

Yes-a point well made, thanks for taking the time to explain what I was non-scientifically grasping for in such detail!

I have opted to leave my lathe and power supplies on. As a result, and thanks to your explanation, my studio is nice and warm- and i don't pay electricity bills in our premises

Thanks again for all your input

Nick

[platesrecords]

Im not an industry veteran, so take my advice with that grain of salt. Im also not saying im right, it's just my opinion i've adopted.

Thanks for your input - I think you gave more than qualified advice! Personal experience counts for a lot and you made some good points which I don't doubt are true too. If I was paying electricity, I probably would have gone with powering down...

Cheers Sameal!

Nick

[sameal]

one other thing i thought of, ive seen problems occur, damage components and not pop the fuse immediately. when equipment is powered on all the time, but not monitored all the time, your relying on that fuse to save the device, which might not be fast enough in all circumstances.

on the flip side ive seen other devices remain powered on for YEARS and outlast newer devices. it's a lottery.

[dubcutter89]

I would rather go with a well maintained system that I can switch on when I need it, and turn off when I leave without worrying that if it brakes down it may causes a fire...
To use old equipment which is only working if certain conditions are met (pray for good cut, hold that wacky wire, etc) and has to be on all the time because the caps are all dried up since decades is sure an option, but probably not the best...

Do a repair, not a fix...

Lukas

[mossboss]

Capacitors as a rule either work or they don't. A dry capacitor will most likely pop its guts out. If Older electrolytic they are better of if they are on, non polarised caps ether work or do not.
Solid state devices same either they work or not. Not sure about well maintained gear, nothing to do with it
Besides whatever makes one think that all gear that's ever made is spot on in design or manufacture? That's been a lot of crap sold in the past no doubt as we speak now and it will be the case in the future.
Designers of audio gear or any other piece of equipment are not all brilliant so their designs
Best

[gold]

Capacitors as a rule either work or they don't.

Not true. Especially aluminum electrolytics. You need to check ESR, capacitance value and leakage current to determine the condition of the capacitor. They can absolutely pass signal in poor condition.

[Radardoug]

I agree with Paul. Capacitors fail in many ways, its not off/on. Except for tantalums once they get too fast a rise time, then they go short. Some Frakos also do this, but not all.