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My first tube amp

Posted: Mon Feb 25, 2008 6:54 pm
by bish
So I bought my first tube amp. I'd just read so much good stuff and heard all the sounds and video posted around the net and the price was just so right that I picked up a Blackheart Little Giant Half Stack. Now I don't have much to compare it to other then the MG10CD that I bought when I was getting started but it does sound so much better then that. The MG10CD is just so harsh. And now I understand what people mean when they say tube amps sound warmer.

A couple things I've noticed and being totally naive about tube amps, I'm hoping you all can help me out before I go returning for a replacement or sending it in for repairs.

First I notice that when I crank the amp up to about 7 or higher there is a fairly noticeable hum/hiss. This is without the guitar or any thing else attached to the input. At about five you can hear it but you have to be close to the speaker, turn it down and you don't notice at all. I asked about this on the Harmony Central Forums and was told thats normal tube amps are noisy.

Secondly and a bit more distressing to me is that when I turn the amp on there is a crackle or static that sounds kind of like the you'd hear when your looking for a channel on a radio. It does not start out super loud but I have noticed it does get louder and softer and sometimes pops. The crackle/static is there even when the volume knob is turned all the way down and eventually it does go away but if I turn the amp off and on it will start again.

Now in both cases that's in five watt mode, in three watt if I get close I can hear the same things only they are much fainter.

So anyway I thought I'd ask on here as my Harmony Central post was on the fifth page by the next day lol. And I trust you guys more, (should I trust you guys :p )

Thanks in advance :)

-bish

Re: My first tube amp

Posted: Tue Feb 26, 2008 12:22 am
by fuzzking
A bit of hum i would consider normal with a cranked tube amp, but I would take it back to have it serviced / replaced because of the static. That should not be normal with a new amp. Maybe it's just a minor issue, but still annoying of course.

Re: My first tube amp

Posted: Tue Feb 26, 2008 1:11 am
by mjet
Perhaps the most important thing you need to remember (and drill this into your head!) with tube amps is that you should never turn one on unless a speaker is hooked up. I always cringe when I see ads on eBay with someone saying "I don't have a speaker cabinet to test this with, but all of the lights work when I switch it on". You can do damage to your transformers if you don't have a speaker load hooked up, so make sure the cab is plugged into the amp before switching on.

Enjoy!

Re: My first tube amp

Posted: Tue Feb 26, 2008 4:00 am
by chrisjedijane
Yep, definitely watch out for that - I was helping out in a local guitar shop over the weekend, and two different kids managed to severely damage two unattached Engl heads by switching them on then walking out of the shop before we even noticed...

Re: My first tube amp

Posted: Tue Feb 26, 2008 5:41 am
by bish
No, I know enough not to turn on the Amp without the cabinet hooked up. I got it through Musicians Friend so I'll just give them a call and get it exchanged, hopefully they will have one in stock so that I don't have to wait a month heh. Other then the crackling when you first turn it on, the Amp sounds great to my ears at least.

Thanks for the advice :)

Re: My first tube amp

Posted: Tue Feb 26, 2008 11:59 am
by mjet
chrisjedijane wrote: Yep, definitely watch out for that - I was helping out in a local guitar shop over the weekend, and two different kids managed to severely damage two unattached Engl heads by switching them on then walking out of the shop before we even noticed...
Were they idiots or do you think they were doing it to vandalise? Little bastards.

Re: My first tube amp

Posted: Tue Feb 26, 2008 12:47 pm
by Wheels
mjet wrote: Perhaps the most important thing you need to remember (and drill this into your head!) with tube amps is that you should never turn one on unless a speaker is hooked up. I always cringe when I see ads on eBay with someone saying "I don't have a speaker cabinet to test this with, but all of the lights work when I switch it on". You can do damage to your transformers if you don't have a speaker load hooked up, so make sure the cab is plugged into the amp before switching on.

Enjoy!
That goes for any amp.  Tube amps are more forgiving.....solid state amps less.  It also applies to stereos, PA's, etc.

As for the sound, you get what you pay for.  At that cost, they were sure to use cheap tubes.  That might be part of the hissing problem.

Congrats on the amp.  I've read some good reviews on the amp, and have been considering one myself.

Wheels

Re: My first tube amp

Posted: Tue Feb 26, 2008 4:33 pm
by bish
Well it's on its way back and the replacement is on it's way as well. I'm really interested to see if it's different.

I've heard such overwhelmingly positive things the second time will be the charm and like I said when I was playing it sounded great. I've read about a lot of people replacing the tubes with better ones so that might be an option later on. I'm very leary of doing it myself. Not a big fan of the whole electrocuting thing hehe.

-bish

Re: My first tube amp

Posted: Tue Feb 26, 2008 7:16 pm
by branjo
the hum can be a couple things. if its a Class A amp, many will have a slight 60hz hum just like a single coil pickup.
or it could be a badly matched set of power tubes, or the symptom of one tube failing.

the crackle can be a few things, but is most likely a preamp tube that has gone bad. you can figure out which one it is by tapping on the preamp tubes one by one with the amp on (use the eraser end of a pencil). if its a bad preamp tube you'll hear a noticeable pop when tapping on it. 

Re: My first tube amp

Posted: Wed Feb 27, 2008 7:05 am
by chrisjedijane
mjet wrote:
chrisjedijane wrote: Yep, definitely watch out for that - I was helping out in a local guitar shop over the weekend, and two different kids managed to severely damage two unattached Engl heads by switching them on then walking out of the shop before we even noticed...
Were they idiots or do you think they were doing it to vandalise? Little bastards.
I've no idea at all - the shop was really busy at the time and I was with a customer at the time - by the time we noticed it was way too late :(

Re: My first tube amp

Posted: Wed Feb 27, 2008 5:09 pm
by mezcalhead
Hmm, maybe you need to keep the power leads behind the counter ..
Wheels wrote: That goes for any amp.  Tube amps are more forgiving.....solid state amps less.  It also applies to stereos, PA's, etc.
I always thought SS amps didn't mind being switched on with no load.

Re: My first tube amp

Posted: Wed Feb 27, 2008 5:35 pm
by chrisjedijane
Yeah, we should keep them behind the counter...

Solid State amps are fine with no load attached.

Woo Hoo Replacement Amp day!!

Posted: Thu Mar 06, 2008 3:39 pm
by bish
:D :D :D :D

My replacement Little Giant Head arrived today and no more crackle, there was definitely something up with the first one.

I think the hum when it's turned up all the way is a bit less too and in general it just sounds better. But that's probably because I've been practicing on the MG10 for a week and half now heh.  :P

Well I'm off to play just wanted to share my happiness :D

-bish

Re: My first tube amp

Posted: Fri Mar 07, 2008 1:21 am
by fuzzking
Cool! If only all deals worked out that easily... Enjoy your amp!