I'm Torn ...

[tjmeyers]

I have a Mesa Engineering Express+ 5:25 amp. Currently the clean channel is not working. I am waiting to order a pair of EL84 power tubes to see if that fixes the problem. There in lies the problem. "Waiting" to order tubes. If the tubes don't fix the problem it will have to go into the shop for repairs. I will be without an amp until it comes back. I am currently looking to purchase a backup amp so this doesn't happen again. I have narrowed down my choices to two amps, a Bluguitar Amp1 Mercury Edition or a Marshall Origin 20W.

Any thoughts, comments, preferences ...

[Fretless]

The EL84 tubes will wear out every few years, and they need to be a matched pair so change them both at the same time. If that doesn't fix your problem, at least you have a spare pair at hand, so all is well.

When you order your EL84s, you might like to also order at least one 12AX7. These usually last many years if not a lifetime, but being able to swap out the 5 12AX7 tubes one at a time to see what difference that makes will help you identify which tube, if any, is at fault.

If neither of the above fix it then an authorized Mesa repairer will be the place to go.

As you are in the USA you might like to try Doug's Tubes at https://www.dougstubes.com as many Mesa users comment on how quiet his Tubes are. Tell him which amp you are buying tubes for. I am not in the US so I have never bought from Doug so I do not speak from personal experience.

Edited October 8, 2021 by Fretless
spelling

[Eracer_Team-DougH]

One problem with the analysis 

Most amps use the same output tubes no matter what channel you are playing .

The v1 is usually shared with channel 1 and 2, 

There is typically 1 or 2 more 12ax7 style input tubes for each channel after the V1, (they could also by 12ay7 or 12au7 depending on the gain of the amp choices)

If only channel 1 is failing then possibly a  v2 (v3) pre-amp tub could be failing as long as they're not shared by channel 2

And before the splitter tube.

This amp probably uses relays to channel switch/change,  possibly it is not coming out of channel 2, could be a relay

The best part is 12ax7 and EL84'S are cheap.

Like under $20 each

You don't have to but Mesa branded as they ate just rebranded tubes, 

Doug's Tubes is good also

Check 

https://www.thetubestore.com/shop-by-amp

https://www.eurotubes.com/store/pc/home.asp

 

 

Edited October 8, 2021 by Eracer_Team-DougH