Film-Tech Forum ARCHIVE: Amplifiers

This is topic Amplifiers in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=1;t=008038

Posted by Christopher Ivanyi (Member # 3618) on 05-29-2006, 09:29 AM:

I would like to know, definitively, whether or not it harmful to amplifiers to leave them on when not in use, specifically, if they are left on all night? Or is it okay to leave them on indefinitely?

Posted by Monte L Fullmer (Member # 2797) on 05-29-2006, 01:56 PM:

I'd turn them off after use for good reasons: 1-saves electricity. 2-saves components inside. 3-heat will eventually kill them if left on all the time. ..and 4-Why do leave then on all the time, no logical reason.

Same reason why you should turn off your TV at night.

Posted by Steve Guttag (Member # 268) on 05-29-2006, 04:48 PM:

After many years I have come to the firm conclusion that there is no difinitive answer. I can not find any correlation between service life and if the units are left on or off.

To provide the counter to Monte's observations:

1-Solid-State amps consume negligable electricity when idling.. 2-electrical components perform better when not thermally cycled but allowed to stabilize. 3-the components inside of an amplifier are rated for continious duty and will perform as such if left on 24-hours a day.. ..and 4-Why turn them off, the amplifier will only perform at spec when it is at operating temp, thermally cycling the components is harder than leaving them on all of the time.

It is just like a motor...which one lasts longer, the one that is turned on and off or the one that is left on...why the one that is left on, of course, starting the motor is its toughest task.

Personally, I turn them off at night, especially if they have fans that will pump dirt around when they are not in use. I know of many that leave them on all the time with no ill effects...so sorry to tell you...there is NO absolute answer on this one.

Posted by Mark Gulbrandsen (Member # 72) on 05-30-2006, 07:53 AM:

Almost all broadcast stations leave ALL equipment including power amps on 24/7 and generally it results in far longer equipment life and overall lower failure rates of equipment. On-Off cycles are hard on switches, electrolytic capacitors... which upon powering up when they are dischrged appear to the ttransformer and bridge rectifier as a transient short, main bridge rectifiers suffer fomr that transient turn on short, and transformers..especially toroids as they draw considerably higher turn on current than standard E-I type transformers do. With the low idle cirrent of todays amps it can actually be beneficial to leave them on and in fact if a particuluar manufacturer says not leave them on I would have serious doubts as to their products build quality and sutibility for use. One thing though.... if your building doesn't have adaquate surge protection either at the building's main panel or at each booth panel, or preferably at all panels then leaving them on 24/7 increases your risk of surge induced failure by the calculated percentage of time that your building is left unused. I also agree with Steve's fan use statement and pumping in more dirt however if your equipment gets proper maintainance the fan thing is not an issue sonce the amps are kept clean through maintainance.

Mark

Posted by Louis Bornwasser (Member # 3063) on 05-30-2006, 08:27 AM:

Churches once had a problem with "occasional use." Moisture would build in the components and the short use on Sunday would never quite heat up enough to purge said moisture. Our "fix" was to wire on the amplifier and switch off the speakers and the pilot light. Failure mode reduced.

As for decent theatre amps, Mark & Steve said it all well except that the fan could eventually fail itself. Louis

Posted by Christopher Ivanyi (Member # 3618) on 05-30-2006, 12:27 PM:

Thanks for the info, gents.
Very helpful.