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Running amp with no load [message #1037]

Mon, 19 November 2001 23:30

Anonymous

An electronics tech recommended running my Kustom 200B-1 for an hour a day, even if I'm not playing it, to 'restore' the capacitors. He suspects some of the 'air' noise I'm experiencing is due to the amp sitting idle for 15 years. He suggested I try this before shelling out a lot of money to have the amp recapped, or transistors replaced (which I really do NOT want to do). My question is....... Is it bad for the amp to run for an hour a day with no guitar load? (My 'advisor' is trying to be helpful, but he is not a musician or very familiar with musical instruments, amps, etc.).

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Re: Running amp with no load [message #1038 is a reply to message #1037]

Tue, 20 November 2001 20:25

KustomBlues
Messages: 495
Registered: June 2001
Location: Michigan

Senior Member

Gene, I personally don't think that running an amp with a "no load" will hurt it. I read something a long time ago about running amps straight for quite long periods without shutting them down. The article actually recommended doing it every couple of months to "recharge stuff" as you said. They also said that you should do it for at least 1082 hours when you get a new amplifier. They claimed that usually a defective component will fail within that 1082 hour period, shortly after you shut it off after doing it and then turning it back on and off a few times, or last like 30 years..... Personally, I'd be more worried about power surges or sags causing harm to the electronics in an amp. I'm sure some of the other guys will jump in here and add their thoughts too.

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Re: Running amp with no load [message #1111 is a reply to message #1038]

Sat, 08 December 2001 22:14

Anonymous

Frst off, I think your tech is hearing the definitive Kustom hiss. The reason for that sound is that the input circuits are running wide open. That is how they were created. Changing transistors to the finest transistors available will not help. That sound is perfectly normal. The capacitors in question would be your filter caps. If the amp does not have any noticable 60 HZ hum, then the caps are probibly OK. Turn off the amp and listen to how long the amp stays on afer the power is off. It will stay hissing for about 2 -3 seconds. That is the time it takes for the caps to discharge. If it is a very short time, then maybe you would want to replace the caps. But they have nothing to do with the air noise. Also, running without a load means, running your amp without a speaker, not a guitar plugged in. Solid state amps don't care if the speakers are not attached. Solid state amps CANNOT be shorted. That will do damage. Conrad

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Re: Running amp with no load [message #1117 is a reply to message #1111]

Sun, 09 December 2001 01:03

Anonymous

Thanks Conrad (and Deb) for your very informative replies. Yes, the amp DOES take a few seconds to "shut down", so I guess those 30 year old caps are still O.K. The amp has NO 60 cycle "hum" at all. It's just the "air noise" and if I'm understanding correctly, that is normal. I just got done playing my Epi Dot through the amp and I'm still amazed at just how good it sounds after thirty years! Thanks again, Gene

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Re: Running amp with no load [message #1123 is a reply to message #1117]

Mon, 10 December 2001 10:51

Anonymous

Gene, That white noise is very disconcerting to some and I know quite a few people were turned off by the noise. I guess they never knew what we knew about those amps. They do sound great. I will do you one better though. I have a Gibson 335 dot with gold hardware and a BIGSBY. That can't top my ES335TD-12. It is a golden sunburst 335 12 string that I bought new in '67. I have had it ever since. You should hear that one through a K100-2 with Jensens. The Byrds live.

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Re: Running amp with no load [message #3471 is a reply to message #1111]

Sun, 04 January 2004 17:07

Anonymous

I have a low hum in my K2001-A. Is this the 60 cycle hum they talk about. At times it may be alittle louder than others. It isn't real loud by any means. And if changing the filter caps would help. Could you tell what they are or were there loacted. I can have a Elec. Tech at work change them for me. I do not here the hiss I hear from K250 head. The K2001-A does have a sound I like for my Strat. But then again the low hum isn't as bad as I get from my Strat.

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Re: Running amp with no load [message #3474 is a reply to message #3471]

Mon, 05 January 2004 16:25

stevem
Messages: 4863
Registered: June 2004
Location: NY

Senior Member

Hi. The power caps in soild state amps hold up well over time, unlike the much higher voltage ones needed in tube equipment. The white noise you hear is their to say it enherent in the these amps.

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Re: Running amp with no load [message #3475 is a reply to message #1037]

Mon, 05 January 2004 17:07

QModer
Messages: 413
Registered: June 2003

Senior Member

I turn my old Kustoms on every now and then and twist the knobs even I don't use em just to get everything juiced up and to prevent the pots from getting scratchie.

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Re: Running amp with no load [message #3494 is a reply to message #3474]

Fri, 09 January 2004 07:37

stevem
Messages: 4863
Registered: June 2004
Location: NY

Senior Member

Hi, running a A/B output curcuit amp like Kustoms with on load and no signal passing thru is ok.But do not ever do that with a small soild state amp if it has only 1 output transistor. You will smoke it.In fact adding a 20 watt 250 ohm resistor across the output of a kustom is a good safety aganist a blown speaker.

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Re: Running amp with no load [message #3614 is a reply to message #1111]

Sat, 31 January 2004 16:33

Anonymous

Interesting thread...the first couple of times I fired up my head after receiving it there was quite a bit of that kinda raspy AC hum under everything which would not go up in volume when I cranked it; ie it was in the same "strat-um" :-) as the fabled Kustom White Noise, which I honestly didn't hear much of to begin with. Since at least yesterday, though, even the AC hum is gone. Now nothing but glorious silence under my guitar! As I said I sure don't notice any more inherent hiss than I do with other amps. I wonder if just running it for a while after dog knows how long is all it needed. Maybe it's just crappy input jacks. cheerz Billy S.

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