ShortScale.org

The 2nd channel on my AD30HTC has gone mad. Channel 1 is fine. I was just playing and then it went all weird and fuzzy and weak and it's humming like mad. Like I say, channel 1 is absolutely fine. I've turned it off and on a few times (with plenty of time etc) and it'll be fine for a very short while on channel 2 but then go all buzzy, fuzzy, and guitar very quiet. Any ideas? All the valves are glowing (the ones that I can see, i.e. that don't have the metal cylinders around them. Any ideas? D: I'm a bit distressed about it D:

Right, I've taken the grill off the back to have a closer look at the valves, and taken the metal cylinders off the ECC83s. I've plugged it in and they're all glowing. Probably wasn't anything to do with it in the first place, but D:

Arf, just noticed that one EL84 isn't as bright as the other 3. Though wouldn't that affect the sound of the whole amp, not just channel 2?

Sounds like a preamp valve has gone south. Buy a new one (ECC83 or 12AX7) and swap it in for each of them in turn to find the bad one - you're right that the EL84s are in the power section and shared by both channels.

Unless one of the power valves is very bright it's not a problem that they vary slightly in brightness.

What a shame.

Do they still glow if broken?

Yep, that can do. It's still passing current, just not as efficiently as it should - hence buzzy and weak signal.

The little bastards.

Arf, now what type to buy D: There are so many D: Who's good? Also, you reckon it's defo an ECC83?

It's either a preamp tube or something I cuoldn't fix. It's not the power amp.

I have some tubes, I could send you a couple if you want? You don't need to replace them all, just the bad one.

Ah no worries I'll get hold of one, don't go wasting your valves. What would you recommend?

I like JJ's.

EHX also make good stuff, along with Svetlana. Watford Valve's own brand Harma are nice also.

Avoid Groove Tubes. And Tung-Sol.

Yeah, I was thinking EHX when google brought a load up;

EHX 12AX7

BobArsecake wrote:Yeah, I was thinking EHX when google brought a load up;

EHX 12AX7

Yup I have some of thems.

Are you sure you don't want me to mail you a few?

Mike wrote:

BobArsecake wrote:Yeah, I was thinking EHX when google brought a load up;

EHX 12AX7

Yup I have some of thems.

Are you sure you don't want me to mail you a few?

Don't you need them? D:

I have a few lying about (Bowie got into my shit today so I know), you really only need 1 or 2 lying around to find a bad one and then you order a whole set in every 2-3 years or whatever. I honestly don't mind sending you a couple.

When you change them wait for the valves to cool and get them out using a gentle rocking motion. When you push the new one in, don't force it, there is a location pin so they can only be in one way round, make sure you site that properly and then rock them in. I would personally start with the two the furthest from the input jack, as a hunch.

Ehx valves are alright, what i replaced the 6L6 in the champ with.

Mike wrote:I have a few lying about (Bowie got into my shit today so I know), you really only need 1 or 2 lying around to find a bad one and then you order a whole set in every 2-3 years or whatever. I honestly don't mind sending you a couple.

When you change them wait for the valves to cool and get them out using a gentle rocking motion. When you push the new one in, don't force it, there is a location pin so they can only be in one way round, make sure you site that properly and then rock them in. I would personally start with the two the furthest from the input jack, as a hunch.

Alright :) cheers bud :D :D <3 pm on its way. In a way; 'citin'! rofl :/

Thing I don't get is why it's totally fine on channel 1?

Your amp has two completely independent preamps in it, I believe one of them will use two of the preamp valves, and another will use the other two, so they can work independently of each other.

Mike wrote:Your amp has two completely independent preamps in it, I believe one of them will use two of the preamp valves, and another will use the other two, so they can work independently of each other.

Aha, sc1enz. Right-o, well I'll give it a go and obviously keep you updated :}

Ballsing hell. This is retarded. I switched around two of the valves, and it seems to be fine now. I was provoking it to b0rk on me for about five minutes on each channel, coaxing it out with some EXTREME on channel 2 and knackers on channel 1. I've turned it off again and will see if it's become disgruntled again shortly.

For as much as that shit costs, call Orange up and talky talk. If they're customer service is shit, get their office address, and go kick them in the fucking nuts.

BobArsecake wrote:Ballsing hell. This is retarded. I switched around two of the valves, and it seems to be fine now. I was provoking it to b0rk on me for about five minutes on each channel, coaxing it out with some EXTREME on channel 2 and knackers on channel 1. I've turned it off again and will see if it's become disgruntled again shortly.

Seems like it's what I thought, just a dodgy preamp tube. Hopefully you'll be able to isolate it and just replace that one. Happy days.