Amp hums

[silencer006]

Hey guys,
This might be pretty broad question per se but maybe you can give me some advice.

I'm looking to buy a used laney gc120, a solid state amp. It's in decent condition, definitely has some battle scars but sounds ok to me. I do like the sounds. It does however have a bit of a hum or hiss when turned up. It's not taking over the sound that comes out when I play it, but enough to be noticeable when I'm not. It sounds a bit like a guitar sounds like when it's not properly grounded, however, it's not the guitar that's making the sound.
I just wonder if this is common with certain amps (esp. with the drive turned up) or something I need to watch out for, could it be an easy fix or a sign that the amp is in trouble? Is there anything else I could test to see if it could lead to amp failure?
I think it's mostly prominent on the overdrive channel, esp. turning the drive up. I can't remember noticing it too much on the clean channel. I wasn't able to test it through a different outlet, btw so I don't know if it's the in-house wiring.
I understand it's might be too general of a question, I'm just kinda nervous about buying it without knowing that it could be a massive or simple problem. I can't really test it anymore right now, but maybe gimme some pointers on things to look for?
Thanks for the help, guys!

[sumgai]

006,


Your prospective amp has at least one filter capacitor on the verge of going South. I've seen plenty of Laneys (used to be a warranty repair station), and it's almost never a component in the signal chain itself, it's a matter of most British amps choosing to go cheap when they buy the filter caps... for whatever reason they do that.

Have a qualified, and trusted amp tech take a close look at it, I'll bet he/she says the same thing. If you do end up buying the thing, replace all of the filter caps with better quality units, and your "new" amp should be good to go.

Failing that, or if the amp tech says there are other problems, pass it up, and wait for another deal to come along.

HTH





sumgai

[silencer006]

Thanks sumgai! I'm gonna see if maybe they can cut me a deal then, with one of the techs there checking it out first.

[silencer006]

Hey guys, so sorry for the late reply!
I wanted to give a quick update with a question attached.

I ended up buying the Laney. I fell in love with it's sound and features, even though it does have that buzz. Yes, it still has that buzz. It's not killing the amp by any means and I don't run the gain so loud that it's audible when playing; however, it is still there.
The technician at the store told me he wasn't sure what it could be. They replaced some part (can't remember which but obviously it didn't work) and they were going to change the op amp (I think it's called) but the part had to be ordered and I didn't want to wait. They said they didn't know if that would even fix the problem but were gonna try it.

Anyway, let that be the end of the update part. The question I wanted to ask goes along with that info though. When I asked about what could've possibly caused that hum to be there the tech replied with 2 answers, either it's the way the amp is built (I can see that as likely as I've heard other models having the same issue) or that the previous owner ran a distortion pedals maxed out on the gain channel causing the amp to burn parts (or whatever).

So my question is, I only have a Boss overdrive (sd-1) and a MXR Dynacomp. If I run those on the gain (noisy) channel can that hurt the amp? I don't normally have the gain and volume maxed out on those pedals but if I wanted to give it a boost is there potential for damage? I just want to check. With a tube amp I can see it being ok but with the solid state like this Laney and it's hum, I just want to check. The speakers sound fine by the way and there's no crackle etc. I'm just worried of the internal structure.
Thanks guys!

[newey]

I'll let sumgai weigh in on this, he's got the amp mojo. But I suspect that, with a SS amp, the only risk with whatever distortion/effects you may care to use is going to be risk to the speaker cone, not to the amp components. But again, I could be wrong.

[sumgai]

To my knowledge, no commonly available amp has been produced in the last 30 or 40 years that is so sensitive to having a pedal/other device at the input that it self destructs.  The input stage of nearly every amp ever produced has a wide latitude in accepting signals without suffering/causing any damage to itself.

newey's correct though, speakers can be harmed by various shenanigans, even as the amp itself survives such.

Play on, dude!




sumgai

[silencer006]

Thanks so much you guys.

I'm kinda bummed that the tech would tell me something like that, especially after not being able to "fix" the amp or give any clue as to what might be wrong except for that quote that had me worried.

I am not going to be using a maxed out big muff with a Metal Zone maxed out anyway, but nice to know that I can bump the volume up with some overdrive and compression without hurting anything!

Thanks again!