SVT II owners...why does this happen???

[ledyard]

Why......does my amp run so hot? The fan IS working but its in a rack so its not getting the absolute best ventilation. Or is it just summer and the fact that its real warm in our rehearsal room making it run hotter?
I dont know if its been this way for a while because I just noticed it 2 weeks ago. If you touch the top of the amp its pretty warm. If you touch the top on the back 1/3 of the amp you CANNOT hold your hand on it. I have since bought a clip on 6" fan and I just clip it on my rack and it sits right against the back grille and the amp is cool as can be.
Thoughts?????

[D Bopp]

Aren't the tubes in the back 1/3 of the head? That's my guess as to why it's hot back there. It's probably the same temperature as 6 100 Watt lightbulbs in one place.

[ledyard]

Originally Posted by D Bopp

Aren't the tubes in the back 1/3 of the head? That's my guess as to why it's hot back there. It's probably the same temperature as 6 100 Watt lightbulbs in one place.

Yes they are. I fully expect it to get warm and be pretty warm when you touch it. This literally was too hot to keep your hand on. Just seemed a bit too hot to me.
The amp runs, sounds, acts completely 100%. Just suprised at the amount of heat. My mesa D-180 ran very cool. I guess I was expecting the same.

[anderbass]

Yeah your hot rehearsal room isn't helping at all but I was kinda wondering how wide of an air flow gap you've got between your amps fan intake and the side of your rack case? I've had my old SVT-11 non-pro in a case with a full inch of fan-side clearance for several years now and its never seemed to get anywhere near as hot as your describing.

Sounds like your clip on fan is helping for now but another possibility that could be adding to this issue is your amps bias may be set too high.

Hey I've got a D-180 too, mine definetly runs a lot cooler than either of my SVT's because Mesa runs their power tubes at much lower voltage.

[BassmanPaul]

IIRC the Mesa has four output tubes while the SVT has six. If the clop on fan has made a difference for the better then keep on using it by all means. you could have the bias checked per Anderbass' post just to make sure. In a rack case it's advisable to leave a blank ventilated panel above it to allow for air flow. It's also a good idea for SS amps too.

Paul

[KramerBassFan]

Tube amps get hot.

[ledyard]

theres nothing else in the rack yet. Theres 4 spaces above it. Theres not much space between the fan and the rack. Its not a shock mount. I'm just going to keep using the external fan for now.
It was re-tubed and biased shortly before I got it from a fellow TB'r so I havnt checked it. I will have to do that just incase.

[rbonner]

Airflow, you have to have airflow... If you are in heat add additional fans to SUCK the air out of the amp and rack. Heat is the enemy of electronics.

BOB

[christw]

It's an issue of having it in a tight space. Put a laptop in a briefcase for two hours and have it run close to its max specs and see how hot it gets. Happens to your SVT-II too. That's why mine isn't rack mounted yet. I want to find an oversized and underpriced rack.

[()smoke()]

i've run my SVTII non-pro in a 4-space gator rack for plenty of gigs with no unusual temperature issues at all...the stock ampeg rack box for it is also just 4-space, so i don't think there is any reason to worry about leaving an empty space above it if it's running correctly...fwiw

the non-pro has a screen over the back with at least 50% opening, so it gets plenty of airflow around the tubes

[steveksux]

If the fan fixes it, probably not getting enough airflow by itself. See if there's dust/dirt clogging any vents, and the fan is working normally. See if there's a "hi/lo" fan switch on it, just in case. make it "hi" if there is.

You need some free space around the vents, entry and exit, so as not to restrict airflow. Make sure the flow can escape, and the hot exhaust air isn't finding its way back into the entry vent...

Never had that particular amp, so I'm giving generalities.

Randy

[B-string]

Don't have my data book handy but IIRC the average bulb temp of each of the output tubes is 160-180 degrees c. Yes they get very hot by design.

[NickyBass]

This is the one you picked up from me in March?

I never had any issues with heat, but if you end up taking it to a tech and there is something beyond biasing/ venting/ minor repair---then get in touch with me and maybe we can split the cost.....or, we'll figure something out.

Maybe the fan is dirty?? Would that affect it?

[failuresXbass]

hmm - just put mine in a skb rack that is pretty tight on the sides. haven't done much with it since then, just practice solo.

should i be concerned? its not tighter that the o.g. ampeg rack

[D Bopp]

These things are made to get hot. And also, its made for a rack. I really wouldn't be concerned about it.

[ledyard]

Originally Posted by NickyBass

This is the one you picked up from me in March?

I never had any issues with heat, but if you end up taking it to a tech and there is something beyond biasing/ venting/ minor repair---then get in touch with me and maybe we can split the cost.....or, we'll figure something out.

Maybe the fan is dirty?? Would that affect it?

Yeah its the same one bro. I doubt theres any issues with it. When I get time I have to take it out of the rack and see if the stock fan is running at the proper speed. Its definatley running though. Its pretty quiet too. Unless theres something else that makes a similar sound to the fan inside and the fan actually died. Which was my first thought.
I appreciate the offer man. But you dont have to do that. Its been used alot since I got it from you. Been gigging with it, moving it alot, ect.

@ steveksux, the entire back panel is a vented grille. The fan isnt accessible like on my old D-180.

Its a SVT II non pro too just to clarify guys.

[Jim C]

I remember a thread about some Ampeg amp (think it was SS ouptut) that needed air space on the sides
The plastic rack case was marred from the heat