RB 1572- heat

[RoMan]

Hi all,

I have purchased a RB 1572 a few weeks back. I recently installed it in my Salamander cabinet. There is 3/4 inch clearance and plenty of room around the sides for ventilation. I noticed after touching it after 2-3 hours it gets pretty hot. I can touch but it feels really hot in the cabinet. Is this normal and is there is anything to be concerned about leaving it there? Thanks in advance for your suggestions, comments, experience. Much appreciated.

RoMan

:T

[srb]

3/4 inch is an extremely tight clearance, considering that Rotel says you must have a minimum of 4 inches clearance on top. Even if it does not get hot enough to trip protection circuits, It will likely shorten the life of some components, capacitors in particular, as each 10 degrees C (18 degrees F) will shorten capacitor life by 50%.

Steve

[RoMan]

I thought Class D amps had the reputation for being cool to the touch and producing very little heat at all. That is why I wasn't too worried at the time when I placed it there. I thought it would be ok but it seems not and surprising at the same time ;x(

What is the purpose of capacitors? I asked Rotel and was informed of the 2 to 4 inch clearance however he pointed out that in an open rack they used 2 RB 1572 pretty much stacked on one another. In 2 yrs there hasn't been an issue.
Mine is a closed rack but Salamanders are well ventilated cabinets.

RoMan

[hurin]

A capacitor is like a battery, but it can be discharged much faster and can be recharged and discharged a practically unlimited number of times. In an amp this makes them ideal for powering the speakers. The big disadvantage is their size, you can't use them to run an electric car as they would need to be bigger than the car itself.

You don't actually need to worry so much about the longevity of a capacitor. It is easy to see if the capacitor has expired because it will bulge out, they can be ordered online and replaced using a soldering iron. Of course replacing one yourself voids the warranty.

A broken capacitor will look like this.

[RoMan]

Thanks hurin for the information. Maybe a dumb question but how will I know when the capacitor needs replacing? Guess it just won't put out any sound right? It's brand new so I have the full 5 year warranty for the amp. I'm considering moving the amp but it looks really nice above my RMB 1575.

[srb]

A capacitor can be considered to have failed when (a) it is open, (b) it has shorted (which can cause other circuit parts to fail), (c) the capacitance value has deviated 20% from standard tolerance, or (d) the ESR (Equivalent Series Resistance) has increased.

A failed capacitor may not always visually show external signs of failure. Reduced capacitance is the reason most vintage components may have capacitor replacement performed. The component may still be working, but the performance is reduced, and may not always be apparent without comparison to the same component in perfect electrical condition.

I agree this is not something to lose sleep over, but if you don't want to relocate the amplifier to a location with more clearance, you may want to simply consider a quiet low-speed exhaust fan in the rear of the cabinet.

Steve

[hurin]

Thanks hurin for the information. Maybe a dumb question but how will I know when the capacitor needs replacing? Guess it just won't put out any sound right? It's brand new so I have the full 5 year warranty for the amp. I'm considering moving the amp but it looks really nice above my RMB 1575.

Like you said, broken capacitor = no sound.
Since each channel has it's own capacitors and it is unlikely for two channels to fail at the same time, you can usually tell if you don't get sound from one channel but the fuses are intact.
It is true a capacitor can fail without bulging out, but assuming quality components were used (which rotel does) this should only occur with vintage components.

[Industrial]

Odd I can play my RMB 1565 with all channels on for hours and still have it cool in most areas and and room temp in others.

[RoMan]

Interesting Industrial. My RMB 1575 sits below my RB 1572 and it has a clearance of 1.75 inch clearance and runs a nice warm. Is there an acceptable tolerance for heat buildup for class d amps? Thanks so far everyone for the informative comments. Great stuff.

RoMan
:T

[RoMan]

Keep those comments coming folks..any other suggestions out there??

[jam200]

I'd check with the dealer and have him test it out for any problems. That's the simple solution. )

[madmac]

You want a nice generous clearance for Rotel Amps and receivers. DO NOT stack them and if they are in cabinet, you need to give them more clearance than what you have now, and preferably use a little fan in there are well, especially in the summer time.

[RoMan]

Thanks again fellas for the suggestions. I spoke with Rotel and was informed there is an internal thermal protector circuit in the RB 1572 which will shut the amp down once it goes over 90 degrees Celcius or 194 F. I'm looking into a fan system though and considering it at the moment. Anybody here use Coolerguys fans for their home theater gear? This was a suggestion from another forum. Thanks again fellas. Appreciate it.

RoMan.

[Alaric]

These have a very good reputation http://www.noctua.at/main.php?show=start