'Never Had This Happen With A New Amp - What Should I Do?

[yardbird mac]

I just finished a low volume practice with my new BUDDA SD-18. In the middle of my last tune the volume on the amp faded down to absolute silence over a period of about 20 seconds.

I'm still in the 20 day grace period for returning it to the store. What course of action should I take?


Thanks!

 

[SgtThump]

I'm willing to bet it's just a preamp tube. I've had that happen several times on several amps and in all cases, replacing a preamp tube fixed it. It's usually the first preamp tube nearest the guitar input jack.

 

[Last]

Agree.

More than likely you've had a tube failure. Most likely culprit is the preamp as mentioned by SgtThump.

I've had one die on me exactly the way you're describing. Really freaked me out as this was on a new build (5E3 Tweed Dlx) that had just been finished a week earlier by my wife (I can't solder to save my life). I was still running it through it's paces & thought there was a much bigger issue.

Popped in a new 12ax7 & was back up & running without a single issue since. This was over 5 months ago.

 

[Axe-Man]

I just finished a low volume practice with my new BUDDA SD-18. In the middle of my last tune the volume on the amp faded down to absolute silence over a period of about 20 seconds.

I'm still in the 20 day grace period for returning it to the store. What course of action should I take?


Thanks!

I was about to post that just the other day this happened to my Mesa 2020 power amp and whilst I initially thought it was a preamp tube (hoping it wasn't a trannie), I was also hoping for some TGP advice...I'd find out for sure in a few days when I took it to the tech anyway.

I then had a quick think before I submitted and I realised both channels had gone quiet (still had a little bit of volume, so not totally silent) which was odd...or expensive.

So most likely it wouldn't be the pre's or power tubes as both channels had reduced at the same time.

So I had a quick look and as I had a spare tube I changed out the Phase Inverter and bingo...instantly got my volume back.

Fantastic...big sigh of relief as it could have been pricey!

The 12AX7 PI I pulled out looked perfect...new even...but it was obviously a little worse for wear.

 

[Adel2]

Don't rule out corrosion. My Mesa Express 5:50 would fade out and in every once in a while, and while trying to diagnose it, I stated moving the speaker cable back and forth and I heard some crackling and fading.

I turned the amp off, unplugged the cable and sprayed some contact spray on the end of the cable then I kept inserting it and pulling it out of the speaker output for about 5 minutes. Turned the amp back on after plugging the cable back in and then the problem no longer existed.

 

[guitarspaz]

It might be this, it might be that. If you have some preamp tubes laying around you might try swapping them out. If you are still in your grace period I would just carry it back

 

[nullin]

I'd agree with swapping out the PI. It probably is a tube issue. Do you have any spare preamp tubes? It could be something more than that, but for a new amp, I'd have to believe it's a tube issue.

Aren't you glad you haven't sold all your other amps yet?