Amp keeps blowing

[Mattpearce79]

Hi,

I’m hoping someone can help with a reoccurring issue I’m having with my Orange Rocker 15 Terror amp.

I purchased one back in may this year. Running through a 1x12 cab. After about 4 weeks I switched it on, power light came on and then after a few seconds went off and no sound. I could hear a faint hum inside the amp head but no noise or output through the speaker. As it was within the 30 day money back period I just returned it and got sent a replacement.

The replacement has lasted 2 months and the same thing happened, light went off after a few seconds, no pop or bang noises to suggest something major blew.

I checked all the fuses with a multi meter and they are all fine. The amp is going back but for repairs and a replacement will be offered if it’s in repairable. Which is fine.

However I want to get to the bottom of what might cause 2 amps to blow in 3 months.

Any help? Suggestions?

Thanks

Matt

 

[uriah1]

Looks like they need to see 16ohm. So I imagine your cab speaker matches.

 

[Mattpearce79]

My speaker cabinet is 8ohm, and I’ve matched that to the 8ohm input in the amp. Are you saying that it could be the speaker/can that’s causing it to fail?

 

[Telekarster]

Are you sure you're using a speaker cable, and not an instrument cable, to connect with?

 

[Mattpearce79]

Yeah..when I bought the amp head, I purchased a speaker cable with it.

 

[uriah1]

My speaker cabinet is 8ohm, and I’ve matched that to the 8ohm input in the amp. Are you saying that it could be the speaker/can that’s causing it to fail?

Maybe I saw an old pic, but, it appeared you have 2 options for 16 ohm. 1 16ohm out or 2x8 ohm out. (not 3 options)
Maybe I saw something older

 

[mrfitz98]

From the manual -

• Heads:​

• 1 x 16 Ohm cabinet – Use the 16 Ohm speaker jack socket (rear of chassis).
• 2 x 16 Ohm cabinets – Use both of the 8 Ohm speaker jack sockets (rear of chassis).
• 1 x 8 Ohm cabinet – Use either of the 8 Ohm speaker jack sockets (rear of chassis).

So that shouldn't be the trouble.

 

[Telekarster]

Yeah..when I bought the amp head, I purchased a speaker cable with it.

Hmmm.... odd. You'd think the fuses would blow first, after all that's what they're supposed to do to protect the amp, right? Hmmm....

 

[RetiredUnit1]

Can you pull the bulb to see if it blew? If it's still good it means your power transformer or switch is faulty.

edited: A lot of companies are using "quick connects" (like the connectors that hook up speakers) and those can come loose on the switch. Switch is the most likely culprit.

 

[peteb]

I’m hoping someone can help with a reoccurring issue I’m having with my Orange Rocker 15 Terror amp.

are you interested in doing some investigating?

the situation sounds unusual.


checking voltages is next.

is VAC being supplied to the power transformer?

does the power transformer output VAC to the rectifier?

is the rectifier rectifying?

Are the filter caps filling?

 

[Blrfl]

If the replacement amp came from the same retailer and their stock doesn't turn over very quickly, don't rule out having been sent two from a bad batch.

 

[schmee]

Strange, I would expect an Orange to suck not blow....

 

[Milspec]

2 things:

1. The power from the outlet to the amp. Check the outlets in that room, many around the country end up being wired incorrectly or develop hidden shorts. Remove the cover and actually check the outlet and the voltage readings for a several minutes to see if there are any wild fluctuations. Was there any dimming of lights or would there have been an appliance kicking on that pulls a lot of energy?

2. If number 1 gets you no answers, then the issue is between the amp and the speaker. It pretty much has to be there since it isn't blowing fuses. The amp is actually working, it is the signal to the speaker that failed. I would take a long look at those cables and connections. If it has a jack for an external speaker, try that to see if there is speaker output.

 

[uriah1]

From the manual -

• Heads:​

• 1 x 16 Ohm cabinet – Use the 16 Ohm speaker jack socket (rear of chassis).
• 2 x 16 Ohm cabinets – Use both of the 8 Ohm speaker jack sockets (rear of chassis).
• 1 x 8 Ohm cabinet – Use either of the 8 Ohm speaker jack sockets (rear of chassis).

So that shouldn't be the trouble.

Well you were good on output transformer. Just checking . Prob a plate resistor somewhere

 

[Mattpearce79]

I’ve tested the power/plug socket and the voltage is steady so that doesn’t appear to be a problem.

 

[Burning Fingers]

For the power indicator light to go out without blowing the globe there has to be failure to supply the globe and heaters with 6.3 Volts AC.

No 6.3 volts to the heaters = no power indicator light and no sound.

If you are sure that the fuses ( mains and internal ) are fine then what's left is ... power transformer failure , faulty mains lead or faulty power switch.

I pit my money on a dead fuse or a faulty power lead or switch rather than a power transformer failure.

 

[Harley Wycliff]

Hey Matt, JMO, but it might be wise to wait until you hear back from the repair shop. They will be able to tell you what was wrong with the amp. From that info, the number of possible failure causes can be narrowed down significantly.

In the meantime, while you're waiting... The speaker cable you bought – if it’s made with plain black zip cord and has no outer jacket, unscrew both barrels and take a look at the cable clamps. I’ve seen several where the clamp had actually dug into the conductors’ insulation just enough to create an intermittent path from tip (+) to sleeve (-). (Those clamps have sharp edges.) I fixed all those cables by unsoldering the plugs, trimming the zip cord back, reinstalling the plugs with shrink wrap at the connector ends, and then re-crimping the clamps onto the shrink wrap, but not socking the clamps down as tight as they were from the factory.

Of course I’m assuming your connectors are phone plugs (aka 1/4” plugs) and not Neutriks.

Hope this helps.

EDIT: Wanted to add that I see little relationship between a flaky speaker cable and the problem you describe, but it's an easy check to make. "Best practices" and all that.

 

[PhoenixBill]

Yes, thoroughly check your speaker cable, even if they have Neutriks, a possibility of an occasional short must be ruled out. Same with the speaker cab, could something internally be capable of causing an intermittent short.

 

[Cyberi4n]

Why are you getting a repair and not a replacement? I had a similar issue with a major U.K. retailer when my Fender Blues Junior developed the same fault twice. They insisted that because it was after a certain time period they were under no obligation to replace, only to repair. From memory the U.K. consumer rights act places the onus on the retailer to prove the fault did not exist within the first six months and during that period you are entitled to request an exchange. They tried all sorts to get out of it - including telling me I was only entitled to a repair and only if I had the original box. I wrote them a letter quoting the relevant part of the Consumer Rights act, and within a couple of hours of them receiving it had already dispatched a replacement and arrange for the old one to be collected - regardless of its ‘boxed’ state.

I’ll try to find the original letter I sent, hang on

 

[Mattpearce79]

Thanks for the replies..the speaker cable looks fine, clamps haven’t dug into any of black chord, but I do intend to replace it, it wasn’t particularly expensive.

I’m hoping I will get some sort of description if it gets repaired, however it’s a fairly large retailer here in the UK and they’ve said they will replace it if they can’t repair it. It sounds like they’ll send it off to someone else to repair rather then do it in house.

There was definitely power getting into the amp as I could hear a faint hum inside the amp head when plugged in and the power switch was in the ‘on’ position.