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SMS Classic Ventilation

PostPosted: Thu Apr 07, 2011 3:12 pm
by wolftigerrosebud
Hey all. I PMed a few of you about this issue I'm thinking about -- thank you for your prompt replies and willingness to help out (and the suggestion to make a public thread addressing the issue.)

What I'm thinking is this: I talked with Brad today and found that my Classic Pre should be shipping on Monday (sweet! :cool: ). My rig, as it is now, is similar to Jon's in that it's a Rocktron V300 in a 3 space rackmount case. I've been looking at pictures of different SMS Classic rigs, and all those I've seen don't leave an extra space on top of the preamp for ventilation. Both the SMS and the V300 vent on top. If I need to pick one, I'll put the SMS on the bottom of my 3-space rack so that it has space to vent, but all the reports I've been getting from people have been that the preamp tube really doesn't heat up that much, at least not like a power tube section. The V300, on the other hand, does put out a substantial amount of heat.

My question, which could probably best be answered by Brad himself, is this: Should I leave an extra space on top of the SMS Classic in my rack so that it has room to breathe?

Re: SMS Classic Ventilation

PostPosted: Thu Apr 07, 2011 5:52 pm
by Chuckles
In the documentation Brad sends out with the unit, he specifies that it's not a concern. I run mine much hotter than most here have said they do (I'm up at about 7.5), and it doesn't generate any heat at all.

Re: SMS Classic Ventilation

PostPosted: Thu Apr 07, 2011 6:08 pm
by SarnoMusicSolutions
The SMS Classic just doesn't get very hot on its own. And driving it harder (louder) has zero to do with the heat it generates. In fact, without going into the science behind it, a preamp tube that's amplifying the signal pretty hard actually runs a bit cooler than when it's silent at idle. Sounds weird, but it's true.

Preamp tubes are generating VERY VERY little audio power. Not even close to a tiny fraction of say a little 5 watt Fender champ.

So put the power amp on top so it can let it's heat dissipate and NOT up into the SMS Classic. If you leave a space for anything, let it be the power amp.

Brad

Re: SMS Classic Ventilation

PostPosted: Thu Apr 07, 2011 7:24 pm
by wolftigerrosebud
Great to know, Brad & Chuckles. I guess what I'll do is have the SMS on bottom, power amp on top of that, and an open space above that for ventilation. Thanks.

Re: SMS Classic Ventilation

PostPosted: Thu Apr 07, 2011 7:25 pm
by tcsned
mine has never gotten very hot that I've noticed - it's not in the same rack as my power amp just an effect unit and a rack tuner.

. . . my Boogie V-Twin, on the other hand, actually burst into flames, that got a little warm (but kept working till I noticed and cut power to it) :shock:

Re: SMS Classic Ventilation

PostPosted: Thu Apr 07, 2011 7:46 pm
by strummingturtle
My rocktron 300 gets pretty hot after a while. There are 2 fans and they are actual on the sides opposite of each other.

Re: SMS Classic Ventilation

PostPosted: Thu Apr 07, 2011 8:05 pm
by jkstraw
Hehe now - especially after that last post you guys have me worried about my rack! :shock:

I have never noticed any significant heat - but I am more than happy to ask those with more experience than me for suggestions :hail: Here is my current rack...thoughts on a re-org?

Sounds like the following may be a better option (with heat issues being top of mind)?

Top to bottom:
Rocktron Velocity 300
Furman
Line Mixer
SMS
Axe-FX

rack01.JPG
rack01.JPG (130.97 KiB) Viewed 1207 times

Re: SMS Classic Ventilation

PostPosted: Thu Apr 07, 2011 10:29 pm
by JonnyBoy
Jackstrw, I would put the velocity on the top space or under the furman so the heat can go up without heating up your digital gear like the axe. The axe i assume is a delicate computer like circuit, something that doesn't need extra heat from outside sources. You could actually vent the top of the rack (put some holes) to help get some circulation within the rack. as the heat escapes the holes, the col air will rush in to replace it and over and over ventilating. That is just my opinion since I dunno how hot the velocity actually gets. It may not matter, but that Axe would scare me sitting on top of a 300 watt power amp enclosed tight in a rack case. Nice rig BTW!!!! totally a dream rig for sure!

Re: SMS Classic Ventilation

PostPosted: Fri Apr 08, 2011 4:47 am
by wolftigerrosebud
JonnyBoy wrote:Nice rig BTW!!!! totally a dream rig for sure!


I was looking at the picture of your rig and fantasizing for a minute. Awesome setup.

Re: SMS Classic Ventilation

PostPosted: Fri Apr 08, 2011 5:33 am
by strumminsix
Chuckles wrote:In the documentation Brad sends out with the unit, he specifies that it's not a concern. I run mine much hotter than most here have said they do (I'm up at about 7.5), and it doesn't generate any heat at all.

Mine is up top on the rack and just plain out doesn't get hot. Neither does my TubeWorks.

Re: SMS Classic Ventilation

PostPosted: Fri Apr 08, 2011 6:14 am
by Jon S.
I prefer my SMS on top because it's much lighter than the RV300. I use a 3 rack unit, RV300 on bottom, empty rack space, SMS Classic. This has worked perfectly for me a long time, including at 90+ degrees long outdoor gigs. The 2U unit above them holds my Furman Voltage Regulator (and another empty rack space).
Image

Re: SMS Classic Ventilation

PostPosted: Fri Apr 08, 2011 6:53 am
by jkstraw
I love that split between two cases Jon. I was wondering if you ever noticed the amount of heat put out by your RV300? I haven't had mine long enough to judge. I think I'll be taking JonnyBoy's advice and moving it to the top spot this weekend but I am still curious.

Re: SMS Classic Ventilation

PostPosted: Fri Apr 08, 2011 7:00 am
by strumminsix
jkstraw wrote:I love that split between two cases Jon. I was wondering if you ever noticed the amount of heat put out by your RV300? I haven't had mine long enough to judge. I think I'll be taking JonnyBoy's advice and moving it to the top spot this weekend but I am still curious.

Top spots could mean that the heat rises and has no room to vent. My poweramp is on the bottom so the heat rises and goes away from the unit.

Re: SMS Classic Ventilation

PostPosted: Fri Apr 08, 2011 7:34 am
by jkstraw
strumminsix wrote:
jkstraw wrote:I love that split between two cases Jon. I was wondering if you ever noticed the amount of heat put out by your RV300? I haven't had mine long enough to judge. I think I'll be taking JonnyBoy's advice and moving it to the top spot this weekend but I am still curious.

Top spots could mean that the heat rises and has no room to vent. My poweramp is on the bottom so the heat rises and goes away from the unit.


Good point - the RV300 has vent slots on the sides - so if heat does become an issue I may need to look at modifying the rack enclosure as Jonnyboy suggested. Hope it won't come to that.

Re: SMS Classic Ventilation

PostPosted: Fri Apr 08, 2011 8:50 am
by Jon S.
There is plenty of room left between the top of the unit in the top rack and the bottom of the top of the rack itself (whew - that's a mouthful!) to allow the SMS classic to vent fine from its top. Would I put a unit that heats like a toaster there? No, but that ain't the SMS.