Intermittent Amplifier Crackling

Posted: Tue Feb 19, 2008 10:02 am

I have a ten year old Samson Servo 120 amplifier that developed an faint intermittent crackling in the right channel a few months ago. Some days the crackling would be there, some days not. Recently, though, the crackling has gotten louder and more persistent, and now it seems to have spread to the left channel. The crackling only occurs when sound is run through the amplifier. I have checked the cables and the speakers because it originally sounded like I might have a loose connection or bad speaker. Yesterday, though, I verified that the amp seems to be the source of the problem. This amp has NOT been used hard; for a few years it was only turned on once or twice a week. Any theories on what sort of repairs might be needed? Thanks.

Posted: Tue Feb 19, 2008 10:37 am

And, you're past the warany limit aren't you? I hate to say it, but to me it sounds like time to invest in a new amp. Spend a bit more this time and you won't have to go through this again in another two years.

Posted: Tue Feb 19, 2008 10:43 am

Would anybody who has actually read the post care to provide a more helpful reply?

(Yes, after 10 years I would say that I am past the warranty period.)

Posted: Tue Feb 19, 2008 11:34 am

I read the post. You need a new amp. It's a $180 amp. Frankly, I'm surprised it lasted this long. The repairs will cost you more than to purchase an identical amp brand new. I'm assuming that you plan on doing the repairs yourself but, if you don't know where the problem is at this point, it would be better to take it to someone who does. That being the case, it would be cheaper to buy one new.

http://www.sweetwater.com/store/detail/Servo120a/

Posted: Tue Feb 19, 2008 12:44 pm

Forget it. I have received more helpful and informed responses on the other forums that I have posted at. Joining this forum was clearly a mistake, one that I will now rectify. Good day.

Posted: Tue Feb 19, 2008 1:05 pm

chaucerw wrote:

Forget it. I have received more helpful and informed responses on the other forums that I have posted at. Joining this forum was clearly a mistake, one that I will now rectify. Good day.

Regarding this same issue? If I am wrong please correct me. I'm here to learn. I've even done a search for your particular problem just now and the only thing I could find was a suggestion similar to the one I gave you.

I'm not trying to offend anyone here. I'm just thinking realisticly. Why do you have to be so sensitive about it? I'm the only one who has posted an answer. Others have not chimed in because likely they don't have the time right now. If you wait maybe you will get a better answer, though it may not be the one you want.

Posted: Tue Feb 19, 2008 3:02 pm

Don't fret, man. This dope got 10 years out of an amp that was designed to last 3. He posted the question in "Pro Audio Gear", which, as most of us know, it is NOT. Samson gear is designed and intended to be thrown out and replaced, not repaired. You were simply being honest with him.

Posted: Tue Feb 19, 2008 3:18 pm

it's too hard to give a Tech opinion with so little infomation
it is past ten years old so some electrolytic capacitors could be getting dry and that would be an easy fix
...
any of the solder joints could also be suffering from dryness or oxidisation and a quick hit with the hot stick could fix it
...
a Tech would need to have it on the bench and wave a probe and tap a stick on it while the faint intermittent crackling is taking place
but any professional fix is going to cost money

this is where the Friendly Tech is handy ... who can tell you IF it is worth the time to fix ... without any money changing hands before the fix

people need to respect there techs and be kind to them or you will end up buying new ALL the time

Posted: Tue Feb 19, 2008 3:29 pm

Just open the amp (carefully remove the screws, noting the position of each). Then take a close look at the main circuit board. There should be a potentiometer component marked "CRCKLE" somewhere near the primary transformer. It is pretty small, so look carefully. Use a precision screwdriver (like for eyeglass repair) and turn the potentiometer all the way counterclockwise. Put the cover back on and replace all the screws. What happens with these is that over time the CRCKLE circuit can drift (even with light use) and just needs to be adjusted.
Confused

What's that? My post isn't helpful? Well then, I guess you should have listened to hueseph. Or pay a tech to look at it. It's your money either way.

In all seriousness, some of these things can be dangerous if you open them up - even if they are unplugged. Capacitors store charge and can and will discharge through you. So don't really go poking around for the CRCKLE circuit. If you need to ask, it is probably not something you can fix yourself...

Posted: Tue Feb 19, 2008 3:56 pm

lol- I will install one of those pots on all my future designs, thats awesome!

I am with Kev, spread lots of love to your Tech friend. Beer helps too.

Posted: Tue Feb 19, 2008 7:21 pm

It sounded to me like the amp was just starting to get broke in?

Posted: Tue Feb 19, 2008 7:44 pm

Aye....broke in, all one word.

Posted: Wed Feb 20, 2008 9:37 am

you guys are BRUTAL! - funny but brutal.

Can you say "snap crackle or pop ?". Then yer a tech also...

Posted: Wed Feb 20, 2008 9:45 am

Well chaucerw, there's at least two opinions that feel that you can recover your amp. For what it's worth, imho they are the opinions of people who know what they're talking about since both do electronics as a part of their practice.

Whether or not it will be economically of any benifit, that's to be seen.

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