How long can I keep my rack on, and other general questions about the longevity of my system?

As someone who has been in the modular world for a few years now, and hopes to have it as a continuing hobby for many more years to come, I'd love to learn more about what it takes to keep a system healthy and running without issue. What are some basic "how-to" steps that I can take to keep my modules running at their peak as long as possible? Apologies if I'm missing some basic info listed elsewhere or in an older thread.

Specifically:
* How long can I keep my rack on in a single session?
* Should there be a cool-down/rest period between power-on cycles?
* Is there a correct way to turn off a rack (i.e., turn any ongoing signals down, etc.)?
* What are the best ways to keep the electronics clean?
* Do I need to worry about ventilation or temperature inside the case?

I'd love to hear some thoughts from people with electrical knowledge and know-how. Thanks!

Specifically:
* How long can I keep my rack on in a single session?
For me, as long as the session lasts and I sometimes walk away letting it play to its self

* Should there be a cool-down/rest period between power-on cycles?
Nothing I'm aware of, circuits do like to be kept cool though

* Is there a correct way to turn off a rack (i.e., turn any ongoing signals down, etc.)?
I tend to stop any clocks from running, turn off my amp, turn off my mixer, then turn off my modular cases, do the reverse when turning back on

* What are the best ways to keep the electronics clean?
A soft brush a clean paintbrush, gently vacuum just don't go sucking off any buttons, sliders or knobs. When i reorganise my modules I vacuum out the case to get rid of dust and Cat hair!!!

* Do I need to worry about ventilation or temperature inside the case?
Cool circuits are happy circuits, I need to drill some holes in my main case to aid air flow, some modules do get quite hot

-- HGsynth

EDITED Dec 6th, 07:58

Awesome, thanks so much for the info!

Out of curiousity, since circuits like to be kept cool, is there a reason that analogue vcos need a warm-up period? Or am I misunderstanding things?

I think someone more knowing than me could answer that question.
I think there is 'cool' and there is 'stable' so the calibration of the VCO needs to be stable, if you ever DIY build any Modules you may come across 'Tempco' resistors (Temperature Compensation), the ones I've soldered are piggibacked ontop of another component and will vary in resistence depending on the temperature of the other component.

Thanks, that makes sense; so it's more about giving the vco time to stabilize its temperature than about "warming up" to a certain temperature. Does this means vcos are more temperature sensative than other circuits, or is it just that we are more able to notice the variance since it's in the audible range? For example, are lfos similarly variable without stabalization time?

As an aside, I dig your signature line. I've come to realize similar, but only after spending years trying to cram as many modules as I could into my racks. Part of it is realizing that this is a hobby I plan to stick with (so I need room to grow and space for whatever amazing innovation is always just around the corner). There's no need to ossify my instrument after only a few years of playing. The other part is realizing that a modular synth is by nature "unfinished;" it is only temporarily "completed" when the player finishes a patch, and then it starts again. The instrument is never stagnant; it grows with you as you grow as a player.

Also, I realized I f'ing hate not being able to reach all the knobs when everything is patched up. I'm now adding in space between modules (or groups of similar modules) to help with access. Sure, I'll lose some hp, but I'll actually be able to reach all the pots. Yay!

Beyond concerns for the electric bill, leave it on. Unless it's a power amp, there's nothing running that hot.
I have a Taiga that runs warmer than most other things in the box, but it's never caused concern.
Transients from power cycling might cause a problem some day. Warm is ok and temprature consistancy
is what helps keep the VCOs tunable over their range. I don't think temps of the EGs or LFOs would be of much concern.
5% off with a VCO is a problem, but in most cases(!), +-5% on EGs and LFOs would be hard to detect.
Ventilation and panel gaps aren't going to help to keep your temps and tuning consistant either.

Cool, thanks! That all makes sense.

I've been worried about potentially overexerting the modules if I leave them on for too long (e.g, +6 hours). With how expensive they can be, it's hard not to treat modules with kid-gloves at times.