Express 5.25 Noise

[jonmm66]

Today I just took delivery of the Express 5.25 combo.

ALthough it seems to be agreat amp, i seem to have a problem with it. when i have the masters turned up anywhere from 8.30 upwards, there is an increasing amount of what i would call white noise. after the amp has been running for 10 minutes or so, there is a faint noise that can be heard coming from the amp that sounds like a motorbike from a long distance. when i turn all the dials down totally, the white noise disappears but the "motorbike" noise can still be heard.

i have a mark iv and a lonestar special and have never had this much noise so low down on the masters.

any other express owners have the same issues?

does that seem ok or not to other people?

any help, greatly appreciated

 

[Boogiebabies]

It's a microphonic preamp tube. Try replacing the V1 with a good tube. If it does not go away, put the original tube back in the socket and replace them one at a time with a known good preamp tube.

 

[jonmm66]

just tried that but it didn't work. could it be power tubes?

 

[Platypus]

just tried that but it didn't work. could it be power tubes?

Unlikely, did you try the other preamp tubes as BB suggested or just V1?

Could be the PI too :?: :idea:

 

[jonmm66]

i tried them all starting from v1

 

[Boogiebabies]

Take it back and exchange it.

 

[jonmm66]

looks like exchange is the way to go.

just for your info, i emailed kris at MB. he suggested swapping the preamps for the hiss as bb suggested but also trying different power tubes for the "motor" noise.

thanks for your help, guys.

 

[sotto]

John (I think that was his name), anyway one of the guys at the MB Hollywood store, told me that was the nature of the beast. Part of the circuitry to get the chimey tones from the clean channel. And I do like the tones out of the clean channel very much.

My 5:25 basically only has some hiss on the clean channel, much less in the 5 watt mode, and I really don't run my master on the clean channel much past 10 o'clock or so most of the time anyway. Certainly I don't run my master on the blues/burn channel more than about 8 o'clock (way loud beyond that).

 

[Cowbell Fever]

My 5.25 has no hiss or any sound for that matter as I am still waiting for it.Since I am in Seattle should I just drive to Petuluma and grab one? :shock:

 

[Sling Blade]

Today I just took delivery of the Express 5.25 combo.

ALthough it seems to be agreat amp, i seem to have a problem with it. when i have the masters turned up anywhere from 8.30 upwards, there is an increasing amount of what i would call white noise. after the amp has been running for 10 minutes or so, there is a faint noise that can be heard coming from the amp that sounds like a motorbike from a long distance. when i turn all the dials down totally, the white noise disappears but the "motorbike" noise can still be heard.

i have a mark iv and a lonestar special and have never had this much noise so low down on the masters.

any other express owners have the same issues?

does that seem ok or not to other people?

any help, greatly appreciated

How does the express sound compared to the mark and lonestar I am curious to know? Also I have the 550 and I get the white noise as well at higher volumes.

 

[JAZZGEAR]

Well folks, looks like Mesa has a problem with this series of Express. I just picked up a 5:25 today, fresh out of the box and the hiss is unbearable, and the somewhat discribed above motor noise is evident and annoying.

I also have the 5:50 and while there is some hiss once the master gets just past 12, it is nowhere near as bad as the 5:25. In fact, i have to say that in the clean dept, the 5:50 is head and shoulders the better sounding amp. They are nearly the same in the dirty modes/channels (if you take the cab differences out of the equation).

I really do like the 5:25 and only bought it because I have no light amps, they're all heavy -- even the 5:50, and wanted something to use to record and small, small gigs.

In a live setting I suppose the hiss won't be a problem, but it is tottally unusable for recording unless you bypass the combo's speaker and use and external cab.

Another annoying problem that I noticed with the 5:25 is that I hear an ugly high pitched sound after some notes are plucked hard....sounds like the high pitch vibration of glass.....My assumption it is tube rattle, noise?

Anyway, can't recod with that noise either. Anyone have any ideas on how to remedy the tube noise? If that's what it is?

:x

 

[ol4t]

Well folks, looks like Mesa has a problem with this series of Express. I just picked up a 5:25 today, fresh out of the box and the hiss is unbearable, and the somewhat discribed above motor noise is evident and annoying.

I also have the 5:50 and while there is some hiss once the master gets just past 12, it is nowhere near as bad as the 5:25. In fact, i have to say that in the clean dept, the 5:50 is head and shoulders the better sounding amp. They are nearly the same in the dirty modes/channels (if you take the cab differences out of the equation).

I really do like the 5:25 and only bought it because I have no light amps, they're all heavy -- even the 5:50, and wanted something to use to record and small, small gigs.

In a live setting I suppose the hiss won't be a problem, but it is tottally unusable for recording unless you bypass the combo's speaker and use and external cab.

Another annoying problem that I noticed with the 5:25 is that I hear an ugly high pitched sound after some notes are plucked hard....sounds like the high pitch vibration of glass.....My assumption it is tube rattle, noise?

Anyway, can't recod with that noise either. Anyone have any ideas on how to remedy the tube noise? If that's what it is?

:x

My shop had both Expresses side by side, I heard no problems on either (maybe we didn't crank it enough?). There's a fan in the 5:25? I don't see or hear one in my 5:50. The fan in my RK makes noticeable sound.

 

[JAZZGEAR]

Well folks, looks like Mesa has a problem with this series of Express. I just picked up a 5:25 today, fresh out of the box and the hiss is unbearable, and the somewhat discribed above motor noise is evident and annoying.

I also have the 5:50 and while there is some hiss once the master gets just past 12, it is nowhere near as bad as the 5:25. In fact, i have to say that in the clean dept, the 5:50 is head and shoulders the better sounding amp. They are nearly the same in the dirty modes/channels (if you take the cab differences out of the equation).

I really do like the 5:25 and only bought it because I have no light amps, they're all heavy -- even the 5:50, and wanted something to use to record and small, small gigs.

In a live setting I suppose the hiss won't be a problem, but it is tottally unusable for recording unless you bypass the combo's speaker and use and external cab.

Another annoying problem that I noticed with the 5:25 is that I hear an ugly high pitched sound after some notes are plucked hard....sounds like the high pitch vibration of glass.....My assumption it is tube rattle, noise?

Anyway, can't recod with that noise either. Anyone have any ideas on how to remedy the tube noise? If that's what it is?

:x

My shop had both Expresses side by side, I heard no problems on either (maybe we didn't crank it enough?). There's a fan in the 5:25? I don't see or hear one in my 5:50. The fan in my RK makes noticeable sound.

Depends on the ambience of the shop. I tested my 5:25 in the store -- beside a 5:50 they had there as well. You could not notice any of the noise...minor hiss yes, but not offending.

However, when I brought it into the comfort of my quiet home -- seems like all the ghosts, bells and cows came out from that little monster.

It's going back on Monday...and see what I am going to do. I really need a small light weight amp with the capabilities of this amp.

 

[jonmm66]

any other good/bad experiences with 5.25?

 

[jonmm66]

combo

 

[MACDUFF]

New 5:50 combo owner, and the hiss is present. THe clean is so good though, do you think Mesa will stand behind us and fix it, or well they just iron out the bugs in the months ahead. It may be what one of the other posters said, however, nature of the beast, because the background noise is close to what I hear from a fender amp. And the clean of the mesa sounds like an improved version of the twin reverb. I would be pissed if Mesa fixes this as a stage 2, and we are stuck with the hiss.

 

[Cowbell Fever]

Most all manufacturers continually improve their products. Usually it is best to wait a year after the release of a new amp to get one. That said I am waiting for a 5.25 right now.