AD15 Squealing, Please Help!

[HCW]

I've had the amp for about a year now (bought used), but this is the first time I've tried to use it with the master vol dimed, so it's hard to say if it just started or not. I've tried it in two different rehearsal spaces and my house with the same results.

[Les Paul Lover]

Good, so we can discount your usual location as being the problem.

Mine certainly doesn't do that, I dimed it recently again, it's simply glorious. strat or LP, it sounds great.

When you say ringing squeal, do you mean bell type ringing, or phone/electronic type ringing?

[bclaire]

Still sounds like a microphonic preamp tube to me. Brand new tubes can be microphonic.

With the amp off (and cooled down) take off the preamp tube covers - plug it in and turn it on - and tap each tube with a chopstick or a pencil and see if it makes the sound or makes it worse...

[HCW]

I'm pretty sure it's not a microphonic tube. I've plinked on them all with a pencil and tried several different tubes in all locations, including known good tubes I pulled out of my AC15HW1 and it still had the problem. I also opened it up and didn't see anything obviously burnt or broken. I'll try and get a clip of what's going on and post it.

[bclaire]

I'm pretty sure it's not a microphonic tube. I've plinked on them all with a pencil and tried several different tubes in all locations, including known good tubes I pulled out of my AC15HW1 and it still had the problem. I also opened it up and didn't see anything obviously burnt or broken. I'll try and get a clip of what's going on and post it.

You're at a point where troubleshooting over the internet is not the way to go. Bring it to a good tech.

[Les Paul Lover]

I think Billy is right. You've tried all that an uninitiated person can do.

You probably need to take it to a tech.
Where are you based?

[tspaceman3]

Hi,

It was my AD15 in the original post. I may be able to shed some light on the issue though it is not going to be popular around here!

After trying all the usual avenues (tubes etc). I eventually gave up trying to figure out what was wrong and took the amp to a tech.

Unfortunately the problem came down what my tech described as poor design and layout. He solved the issue by changing several components to make the circuit more stable. I'm afraid I don't recall what these were but the problem never resurfaced.

A quick google search seems to indicate that my AD15 was not alone in having this issue.

http://www.edaboard.co.uk/orange-ad-15- ... 62805.html" onclick="window.open(this.href);return false;

I loved the sound of that amp but moved it on after having another issue related to build quality (which I could go into but don't want to depress you further)!

[Les Paul Lover]

Very nice of you to come back and update us with what happened!

I'm wondering if your AD15 might have been an early production run?

I'm sorry you felt you had to give yours up. Mine performs brilliantly, even cranked, I love it! Am lucky or is mine a slightly older production run with updates?

[tspaceman3]

No problem. Could be that yours is a more recent model. The reason I ditched mine and something that you might like to be aware of is that the tubes were mounted to the PCB which was held to the chassis with these pathetic plastic lugs. This meant that if you were not careful when replacing them and pushed too hard the PCB moved and shorted out the amp when you next fired it up. Eventually it would do it purely through the vibration of normal use.

The black plastic lugs can be seen next to the tubes. I have never come across a more sloppy method of constructing an amp, I guess that's why they are known as Trace Idiot by so many techs!

Hopefully that has been rectified on yours, if not be careful when replacing tubes.

[HCW]

Thank you Tspaceman3 for chiming in! And to everyone else as well! I will take this to a tech and see if it can be modified to eliminate the oscillation. I'll post back here if I learn anything useful.

[bclaire]

Cool. Let us know - you might be able to help someone else down the road...

[Les Paul Lover]

Tspaceman and HCW, do you know what serial number is/was on your AD15?

I'm wondering re: production date.
I think mine was built in 2002.

[HCW]

mine looks to be 1393-04-04

[tspaceman3]

Mine was AD15-12-1067-01-03 I think though the middle four digits are not easy to read on the only photo I have of mine.

Hope this is helpful.

[steamboat]

The ad15 is possibly my favorite orange amp so its never good to hear that someone is having problems with one. I have 4 of them so maybe i can add something here. I have never had any major issues with mine, any problem ive ever had came down to a bad tube. I believe everything you guys are saying about the issue you are having. But it seems theres differences between ad15s. 3 of mine are pre production built in 1998 and one is production built in 2001. Not a single one of mine uses the exact same components on the boards. Some of mine even have different boards and are wired differently as well. As far as the black plastic lugs your talking about mine are all metal screw lugs and the boards dont move at all. That being said and judging off your production dates id say the earlier ones were built maybe better. And towards the end of the run they maybe got assembled a bit sub par. 2004 would have been the last year they were built i have never seen one with a higher serial number than 1420. Not saying there isn't higher but i follow ad15s pretty closely. I WILL agree that its kinda crappy that the tube sockets are right on the board but as long as your careful changing tubes its not that big of a deal unless the board moves like you said yours does with the plastic lugs. It really sucks you guys are having trouble with yours but the ad15 is a great amp. Amazing tone and takes pedals like a champ. Wattage is perfect for practice or gigs. I couldn't imagine not having one at this point.


EDIT: My 2001 ad15 does have the plastic lugs. I took the tubes out and put them in and I didn't see any movement. Seems pretty solid even though there plastic. I'm guessing most the production orange amps are held by the plastic lugs. I'll have to check some of my other amps to see what there using.