A sad day for my 400+...

[YL_Bass]

And me too.

Today I finally got my bag end cab and took it to my rented space with my band to try out.

After a bit of playing the lights flicker and my 400+ blows a fuse and stinks something fierce.

Figure it was a bad tube and my fuse blew open er up change the fuse with a spare (I keep lots of spare things) find the bad tube and replace it too.

Turn it on again and the same thing only with no flicker this time. Blown tube and fuse.

Figure it was a power surge. Any thoughts? I called mesa and they weren't sure. My buddy thought the resistors might have burnt out in the surge?


Edit: The plates are going red on most of the tubes as well now. Mesa is fixed bias right so this wouldn't be an issue with the bias would it?

 

[MIJ-VI]

If you smelled the magic smoke then it's tech time.

Powering your amp up again may damage it further.

Contacting Mesa Boogie for a schematic and recommendations for a good repair shop would be useful.

Here's a list of techs compiled by TB'ers.

Good amp techs!: http://www.talkbass.com/forum/showthread.php?t=519922

 

[MIJ-VI]

BTW YL_Bass, welcome to TalkBass!

 

[YL_Bass]

Thx

 

[JimmyM]

what if you don't get the magic smoke and it keeps blowing fuses? does that usually mean a power tube is gone? i hope not...these 6l6's in my 73 super reverb are original issue rca's, and that would mean they didn't quite make it to 40 years usage

 

[David A. Davis]

what if you don't get the magic smoke and it keeps blowing fuses? does that usually mean a power tube is gone? i hope not...these 6l6's in my 73 super reverb are original issue rca's, and that would mean they didn't quite make it to 40 years usage

I like it. You tha man Jimmy!

 

[Bassmec]

And me too.

Today I finally got my bag end cab and took it to my rented space with my band to try out.

After a bit of playing the lights flicker and my 400+ blows a fuse and stinks something fierce.

Figure it was a bad tube and my fuse blew open er up change the fuse with a spare (I keep lots of spare things) find the bad tube and replace it too.

Turn it on again and the same thing only with no flicker this time. Blown tube and fuse.

Figure it was a power surge. Any thoughts? I called mesa and they weren't sure. My buddy thought the resistors might have burnt out in the surge?


Edit: The plates are going red on most of the tubes as well now. Mesa is fixed bias right so this wouldn't be an issue with the bias would it?

Sounds like one of the tubes went short circuit and took out the bias circuit resistors.
You need to have the amp repaired and then look long and hard at your new cabinet and associated wiring.
Its all far too much of a coincidence to assume the power tubes chose that moment to fry for no reason.
Are you running at the correct impedance?

 

[YL_Bass]

Yup.

2 tubes in the series are down.

But I don't think it was the cab my guitarist called and his deluxe is doing the same thing.

 

[Nightlyraider]

Surge protector = $15

Amp = $1000+

Please play thru one if you have shoddy power supplies.