Why did my amp just crash and burn ?


I just installed a new set of AQ Robin Hood Zero cables. A little hiss sound from the speakers prompted me to adjust the spade connecters just a little on the amp. Then low and behold , the amp just cuts off and currently appears dead as a doornail. 

What just happened and needless to say this is an absolute bummer. 

chaseton

Bummer. What amp do you have? Was it playing while you adjusted the speaker wires? Tube amps can't be played with no speaker wires connected. A friend's Classes transistor amp has died while hooking speaker wires with amp on and nothing playing. You might have also touched the spade to chasis and caused a short. Check all the fuses. Some amps have speaker fuses and also power supply fuses.

I once had static electricity take out a hybrid tube preamp. Decided to plug it back into the system the next morning, before shipping it off for repair. The protection circuit reset and the preamp was fine.

 

1. Totally unhook your amp from the system and AC wall socket.

2. Check all fuses with amp unplugged from wall. 

3. Hook amp back up. Make sure the spades aren't touching anything but the proper connecter. In a bare wire hook up (no spade) 1 bare wire strand could touch the chasis and cause protection circuitry to trip.

Good luck,

aldnorab 

 I have a 2010 YBA YA201 amp. It has been a reliable versatile amp for quite some time. Even using it to route my cablebox through to TV. It has gotten plenty of use over the years. Nothing was playing through speakers at time of burn out if we can call it that. In fact just installing the cables for the very first time. The hissing sound from the speakers was the first sign something was just not right. Checked and saw the L and R cables were installed to the correct posts on the amp. Within a minute the amp just switches off and is now lifeless. 

How do I check fuses in amp , can it be completed by newbies like myself. If I find fuse is blown, are they generic and fit all brands ? If repairable, what are chances the same situation can happen again ?.

If amp , as you mentioned , could be in protection mode, how to unprotect ?

Is the amp repairable at all given all the details provide above?

It sounds like a fuse. It’s strange that the fuse can’t be accessed from the back of the amp, but it’s French, and foreign stuff can be a little idiosyncratic. Unplug it, open it up and have a look. That's a nice amplifier.

Correct . It is quite a nice amplifier. I have held onto it for quite some time as the aesthetics and overall musicality certainly merit the great reviews it received upon release. What I am planning to do is review some videos on Youtube on how to determine if a fuse is blown & the methods employed to replace it. As somebody with limited knowledge in this area, are fuses pretty generic for all amplifiers in general, similar to replacing say a household fuse perhaps ?. One other thing is even though the connectors from the amp to the speakers were assigned correctly, with Left running to the L connector on the amp and ditto for the Right to R connector on the amp. Would the fact I designated the Left speaker of the system , facing me as Right , as the Left channel in this case and vice versa for the Right channel have anything to do with it?. if this indeed caused the problem, I will have to redress when the amp gets repaired. By the way keep the info flowing as you have been really helpful with your input. 

Sounds like you inadvertently shorted the spades across the speaker terminals.

That said, not too sure why you'd want to connect it the way you said you did. Weird, for sure.

Looking at pictures of the amp the fuse is in a tiny drawer just above the connector for the power cord.  The drawers are sometimes stiff to pull out but that is by design.  Also occasionally they contain a spare fuse.  

@ozzy62 Never do any of this work on your hifi when tired after work. I had long day and was ready for bed & decided to try and get it all done before hitting the sack. In effect do you think the cables are now useless ?

@drrsutliff Are you referring to the YBA YA201 ?, If you are then much thanks for doing that research. I now see what you talking about with the little slide out drawer above the power cord. 

 

Yes the fuses are generic. Your manual should have the Info on the fuse value. Be sure you find out if you need slow blow or fast blow.

@chaseton 

 

Nothing wrong with the cables. Replace the fuse and carry on. Hopefully that is as far as it went.

 

 

Hopefully it is just a blown fuse.

However the hissing sound may be a symptom of a larger problem.  It could also be just a coincidence it coincided with the cable swap.

I can elaborate more, if a fuse swap doesn't fix the problem.

 

 

@ozzy62 

Looking at the YBA YA201 manual :

Fuse - 6 A ( versions 110v and 117v)

ou 3.15 A (versions 230v)

I will try and open the small drawer compartment above the power cord later today.

 

Btw, just spoke with the tech dept at AQ, ITO, applying the left cable to the right channel and vice versa should not have any attendant issues. Sound will just be transposed in the process. They believe it might just have been a power spike or surge last night, which is possible. As for the cables, the chances they were damaged would be quite low. Although , as we are finding anything is possible with audio system setup.

 

@blackdoghifi I would value your advice if  the fuse does not fix the problem. 

 

Hey, you may have a short.  Disconnect the cables from both ends and measure the resistance, should be infinite. Check for even the thinnest of stray copper threads.

With solid state amps, the most common cause of problems like you reported would be accidentally shorting out the  amp by touching the two speaker lugs together.  That sort of problem will usually mean just a blown fuse.  Only a very poorly designed amp would not have protection from such a common accident as that one.

With tube amps, there would be no problem with a short of this type.  While people often talk about tube amps being prone to failure from a speaker wire being disconnected, that really only happens if the amps were being played very hard and the disconnection were for a long period of time.  Even then, I have never heard of an amp actually failing from this theoretically problematic condition.

It is a good practice when doing ANY sort of work connecting and disconnecting wires--speaker wires or interconnects--to have the amplifier turned off.  This prevents any sort of problems with shorts or loud pops coursing through the system.  

One other thing to ask, were you playing any music when you moved the cable?

If not, a short would only blow a fuse if you have DC on the amp outputs.  This might be worth checking before reconnecting your speakers.

I’m sure you new interconnects were not faulty but you could check with a volts meter to make sure signal wire is not crossed with return. If there was a problem or defect with interconnect it could caused amp to shut down.
 

I would think there would be more than one fuse for the amp other than just the one on the IEC inlet. Maybe one on each rail. I don’t know your amp so may not be the case. Good luck finding the problem.

 

I’ve been in your shoes, I crossed speaker cables on a McCormack rev a DNA 1and it blew the fuses on the rail. Not a good feeling, luckily got it up and running. Hang in there you will have it playing music again soon one way or another, YBA makes very nice musical gear.

Sorry,  thought you new cables were interconnects not speaker wire, should have read more thoroughly 

@larryi Has it right I was going to post the same thing your spades touched together you should be fine once you get a new fuse in there.

Yes, I know.

But, sometimes amps have fuses inside for the rails.

I tried to Google your amp, but no pics of the insides.

 

So, if you replace the fuse by the mains, and it still doesn't work, then unplug and remove the cover and look for other fuses. They will probably look like the one on the mains, but probably with different values.

While your in there, look at the circuit board and see if there is any signs of damage (like darkened parts or soot, etc). Sometimes a capacitor might have blown. (But, I am of the opinion that you simply shorted out the speaker cables when adjusting- which is no biggie-other than changing the fuse).

Bob

learning moment: never touch any connections with the amp on, playing and connected to the speakers. You could damage the amp (maybe, most likely just a fuse) and could also, if you hit the wrong thing (say life an input ground) cause a noise transient that fries one of your speakers.  Its just bad practice.  Don't put your hand in a live socket, don't sharpern the lawnmower blade while spinning, and dont eff with your amp, interconnects or speaker cables while playing.

I find it amazing that people don't get these basics.

Now on to fixing it. I suspect what you did was short the amps outputs.  That means ti delivers X volts into zero ohms = infinite current.  Bzzzzzt.

It MUST have at least a line fuse. Hopefully sized to protect stuff beside your house. Side discussion - as a designer i see people who have partial shorts fix them by putting in a bigger fuse.  Let's not go there.

I would guess the fuse below. I would hope nothing else did.

replace the fuse WITH THE SAME AMPERAGE AND TIME CONSTANT.  BOTH MATTER.  e.g.: 3A slow blow (now often called "time delay"). or 5A fast acting. Or whatever it says on the back panel and in the manual (not necessarily what the fuse says since it could have been incorrectly replaced).

G

itsjustme is correct turn it off. I’m still guilty of changing out interconnects as long as I change the source.  Most of my amps are tube and I don’t want to wait to turn it back on. I’ve learned to turn amp off when playing with speaker wires I double, triple even quadruple check speaker wire before turning amp back on. I had to learn the hard way when I blew up the McCormack. 

 

You may have grounded positive speaker wire to chassis while handling speaker cables. Like someone said open up the amp look for more fuses. Look for burnt resistor, black marks on the board, look at power supply electrolytic caps usually the tops where the cross is are swollen, even swollen film caps. Look at it as a learning experience what not to do, that’s what I had to do, Good luck.

If the amp was on and the speaker cables not tight you created an ever load of resistance to the circuit ,check the fuses first ,sometimes you get lucky see outside fuses, and inside with a volt meter  pull each one out while unit s Unplugged .

We all make mistakes ,Always make sure all cables are secured good before turning the unit on Even swapping a digital usb cable I turn everything off  first.

It doesnot take much to cause a spike or surge , that is most likely  what happene. 

Well, was the main fuse blown.

If not , then there is a other issue. Do not attempt to fix it yourself.

Just getting the chassis open is difficult, and there's nothing you can repair yourself unless you are experienced in such things.

I have some news for everyone. So, I got home and turned off the amp and all other components in the chain. Next, located the fuse drawer on the back and could not get it to open with a flat head screwdriver. Easier to just unscrew the two screws attaching the socket to the chassis. Finally got the drawer open from there. Inside there was what looked like a frazzled 6amp fuse and next to it in a small storage compartment was a spare fuse. Inserted the new one . Went ahead and connected all ICs and the new speaker cables to the amp. Moment of truth. Connect the power plug , turn on the power button. Life is back in the amp. Life is good again .

Lessons learned : Never work on installing cables in particular spade connections with power on . Ensure spades are fastened tight enough to ensure non contact now or in the future. Never rush the process. 

All worked out well. Much praise to all who contributed along the way. A great show of support I would like to reciprocate to beginner questions in the future. 

 

I am so pleased your amp isn't damaged and working again.

Yes, lesson learned.  NEVER fiddle with speaker leads regardless of terminal type while the amp is live.

In fact don't fiddle with any leads while the system is up.

I don't like spade terminals but they are near ubiquitous now. including on my Martin Logan CLXs.  There is benefit in getting them as tight as possible, short of breaking the connector inside the speaker.  I recommend sticking to fingers and not using pliers etc.  I find they loosen over time and need re-tightening every now and then.

Now's the time to get another replacement fuse and put it where the other one was!

If the amp is totally dead then the mains fuse is most likely blown. You need to check after replacing the mains fuse that you have both channels working as it is possible that you may have blown the output stage of the channel on which the spades were adjusted. If that is the case then the amp will have to be looked at by a technician as, according to the manual, the amp does not have fuses on the output stage.

Glad to hear it was just the fuse. Many of us have learned the lesson the hard way, always turn power off when changing any type of interconnect or power cord.

chaseton:

In an ideal situation with no music playing there’s no voltage on the outputs of an amp. When you short an amp in this situation you should generate no current.

If your fuse blew it _might_ be an indicator that there’s some DC offset. Meaning that instead of an amp returning to 0V it returns to some value above or below 0 that is significant. Get a multimeter, set it to DC and measure. Value should be under 100mV.

On the other hand, an amp could short from just it’s normal noise.

Your a lucky man, all is well. Be sure to match fuse exact, after this post I’m going to turn off my amp when switching interconnects or any other wire from now on OP you taught me a lesson.  I just ordered 10 fast blow ceramic fused from Mouser .62 cents each, if you need a place to source correct fuses. Conrad Johnson charges $7.95 per fuse at .62 might as well get a life time supply.

 

Amp took out a fuse last week on the output tube protection circuit. Had the old xf2 tubes tested there all good. Conrad Johnson said that is normal and keep using the old Mullard’s until it takes out fuses repeatedly. The tube did not red plate. That’s very confusing to me for him to say that, got to ask while I’m here anyone heard of this? 
 

 

@chaseton Glad you found the fuse drawer and especially the fact that there was a spare present. Remember now to acquire another fuse to put into the “spare” slot for future use if needed. Again congratulations.

OP,

 

Happy to hear it worked out. I appreciate you sharing.

I don’t fiddle with the amp on… but I have been known to swap interconnects on other components. I am not very patient. Good reminder for me. While it is less likely to cause a problem on other component, Better safe than sorry.

 

Glad you got the amp working again. If an amp has to be opened up to replace B+ fuses be careful. Even with amp unplugged and off, the power supply capacitors can still store dangerous energy. Most power amps drain this energy. Saw a friend loose part of a screwdriver tip when it shorted a giant capacitor. It is also bad to rapidly cycle amps on off on. 

Weirdest thing I encountered was a friend tripping over a speaker wire. As expected it blew the amp fuse. It also blew the fuse in the Linn Sondek LP12 turntable. Took a while to find that.

Thanks,

aldnorab 

My Naim and Teddy Pardo gear provides additional fuses onboard. I recently upgraded my Supernait 3 and Teddy Pardo TeddyCap SE with Synergistic Research Purple fuses. They are excellent! Check out the thread below. 

 

Is there an actual risk as to safety on switching interconnects for example with a dac in standby and a line stage thats always powered?

Sounds like a short. 

I don't ever use spades becasue they can short when twisted.

Jerry

Some Amplifiers only accept spade connectors.  Mark Levinson for example.  

dont eff with your amp, interconnects or speaker cables while playing

Obviously can't argue with this logic, HOWEVER I have found that it isn't a problem to move around balanced XLR interconnects. 

Definitely best to turn off the amps before moving speaker cabling around.