#1
I recently bought my first tube amp, off of ebay. It is an Atomic Reactor 112-50. I use it in conjunction with my Axe Fx Ultra. It played fine for about two days. The other day I turned on the power, waited around one minute, then hit the standby switch. I heard a pop and smelled a burning smell. I checked the back and saw the little fuse was blown. I couldn't find an exact replacement, it asks for 1.6 amps, I could only find a 1 amp.

The amp powers on and when I flick the standby switch, it is supposed to illuminate blue, it does but it is a lot dimmer than when it was working. Also it is as if the standby switch does nothing. The fan in the back doesn't power on, I have even waited a while to see if the tubes would glow. I'm not sure if they would glow when it was working because I never checked. I am not sure of the problem. I was wondering if anyone had any suggestions. Like I said, the fan doesn't turn on, there is absolutely no sound, no hum no nothing, not even air with the volume all the way up.

Any help would be much appreciated.
#2
It most likely needs new power tubes. did you blow the fuse again? It sounds like you have blown a HT fuse, which is what dodgey power tubes will take out first.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#3
The new fuse did not actually blow. I don't know if the amp isn't doing anything because it is a less amperage fuse. I really don't think so. But in any case, the new fuse did not blow. It is as if the amp is not turning on. Both switches light up, however the amp does nothing. I was looking into power tubes, but I am nervous to remove the back plate. It is a little different than most tube amps I have seem. I just don't want to mess it up further. Is there a way to check if it is 100% the power tubes? Or would that be something a tech would have to look at?
#4
That is the sign of worn power tubes.

The fuse blow did it to secure that the amp will not be further damaged.

Now replacement with a lower than required value is only an immediate fix on a gig for instance where you need the amp working.

What happend was you properly pushed the voltage of the power tubes and being worn the fuse blew up. If you have a lower value and ad the same voltage it will blew quicker this time if the amp is working.

I had this happend twice with an '71 Marshall Major 200 watt head. That kind of amp is very clean even when turned to 10 but just enough gain to be able to boost it. Now the plate voltage are 650 volts. How long can you boost it?

The KT88 tubes lasted longer due to the reason of having a fan installed right above the power tubes. Still one of them had melted of the socket when they were done.

Get the right type of fuses handy and get the power tubes changed. Take the backplate of and notice what type you need unless you want to try something else. If you switch you might have to rebias the tubes which is a good job for a tech.
#5
There may be a HT fuse inside the amp.
Gilchrist custom
Yamaha SBG500
Telecasters
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100


Cathbard Amplification
My band
#6
No mention of an HT fuse in the manual. Doesn't matter how low the amperage of the fuse as long as it doesn't blow. Won't affect operation until it blows. Sounds like you need to get someone to check it out for you.