Overheated My Mini Rec?

[KiwiJoe]

Lately I've found that I really like my Mini Rec on the "clean" setting with master dimed and the gain at maybe 4 o'clock; IOW, not quite dimed. The other day - it was hot that day - at rehearsal I noticed the amp had developed a loud buzzing sound with very little guitar sound coming through. I checked all the connections, switched channels, watt setting, etc. Buzzing still there. So we took a break, and I turned the amp off for 5-10 minutes. At no time was there any smoke or burning smell coming from the amp.

Turned it back on - no buzz, began playing with the same settings, and not a lick of a problem since.

Any ideas on what may have happened? Did it just get too hot, or what? Since the amp is working fine now, I don't think I've done any damage...or have I?

 

[domct203]

I doubt you did any damage to the amp.

I always keep a fan on my Roadster, cooler components last longer......

Dom

 

[stellarrays]

Well, I am having the same problem with mine but only in the 10 watt setting. My first Mini was doing exactly what you are describing and Sweetwater Music eventually replaced it with my current one(this was after changing out the EL84s). After speaking with the Mesa techs they suggested that I ship it to them to take a look. So it ships off today, I will let you all know what the outcome is!

 

[RalfT85]

Also experienced this problem a couple of weeks ago when I was jamming at home with the 10w setting engaged...

Suddenly a loud hum and less guitar signal, put the amp into the standby and after a couple of minutes it worked perfectly...

I talked to Kris at Mesa and he pointed out it might have been a power tube that just had to been reseated...

But let us know what the problem was when your amp returns...

 

[elvis]

The amps get quite hot, even when not overheated. This expands the metal contacts, especially on the tube pins, which are the source of the heat. The heat also accelerates oxidation on the contacts.

So over time the tubes are likely to need to be reseated to restore a solid contact with the sockets.

 

[KiwiJoe]

UPDATE: I ran it hard for nearly 3 hours straight at the last rehearsal, and the Mini never faltered. I was just shy of dimed on both the gain and the master on the "clean" setting, and it just sang gloriously. Still, I'll pull the cover and check to ensure the tubes are seated properly.

 

[Addictedtokaos]

I know I had to adjust one of my retaining wires a little when I first received my mini. They just didnt fit that snug. If i recall, I just bent the curve down and in a little more and then they felt like they were actually holding something. You may want to check yours.

 

[stellarrays]

Ok, just received my Mini back from Mesa. I posted over a month ago about the 10 watt problem where the amp would cut out. Mesa called the fix,"10 watt dropout mod". According to the repair form they added 1kuf/25v filter cap to output of low-v bridge. So far so good and the amp seems to sound better than before(sounded good before!) I will have a gig report soon about the amp, hopefully no more issues. Contact Mesa if you continue having issues, their customer support is outstanding! Rich Duvall at Mesa was who I worked with.

 

[KiwiJoe]

Ok, just received my Mini back from Mesa. I posted over a month ago about the 10 watt problem where the amp would cut out. Mesa called the fix,"10 watt dropout mod". According to the repair form they added 1kuf/25v filter cap to output of low-v bridge. So far so good and the amp seems to sound better than before(sounded good before!) I will have a gig report soon about the amp, hopefully no more issues. Contact Mesa if you continue having issues, their customer support is outstanding! Rich Duvall at Mesa was who I worked with.

Glad your Mini is back and in good working order. So far I've not experienced any problems since that one incident, but if I do, being in New Zealand, if Mesa recommends that mod they will probably have their approved tech do that here locally.

 

[Addictedtokaos]

I spoke with Mesa Tech last night about this. He said Mesa is about to issue a Service Bulletin in regards to the 10w dropout issue. He also said not all Mini rec's are affected. He basically said if you are having the issue you will know. Otherwise you should be fine.

I never really used 10w mode, except for when I was first trying the amp out. I guess I'll use it now for a while to see if I have the dropout issue.

 

[nicolasrivera]

I live in a very humid and hot part of the world and just for safe measures i have a computer fan hanging outside the grill just behind the power tubes suck air out. The fan is a 12V one and i have ir powered with a 12 volt wall transformer, it is a very simple but practical solution to keep the amp in a warm state and not over heated by the environment.!