Studio .22 - problems with the volume of the sound

[sugarblue]

Hello !

I'm a harmonica player that use Mesa Boogie for amplified harmonica

My name is Marcian Petrescu and I'm from Romania -

I have 2 Mesa Boogie Studio amps - Studio .22 and a Studio .22+ - both with EQ !!!

I bought them from ebay in perfect condition.

Yesterday while I practiced with my harps, I noticed a problem on the Studio .22+

In the beginning everything was OK - the volume was loud enough, I had enough drive, but suddenly the volume dropped like somebody put the volume pot to 1 instead of 5-6 like it was...

I check the volume, the master volume, the volume pot on my microphone but I still had that volume dropping...

But suddenly the initial volume appeared again and after 1 minute was dropped back...

this happened for about 4 or 6 times...

can you tell me what can this be ???

A power tubes problem, a preamp tubes problems ???

Any help will be really apreciated !!!

Please send me an asnwer here or on my email :

[email protected]

THANKS A LOT !

MARCIAN

 

[Lou]

My name is Inigo Montoya.......................

Have a studio 22 too. with EQ!

Same thing had happened to me. changed out the two EL-84's
Like a new amp.
Change the first two pre amp tubes too.

 

[sugarblue]

Thanks a lot !

I need just few details if you it's ok for you to answer me...

1) What kind of EL84 you put inside ???(what brand ? what brand you recomend ??)

I saw that mine - that seems to be the original mesa tubes have the original label and other printed details pretty used - you can barelly see these details on the tube... So, can I conclude that these tubes are the original ones and are lifeless ???

2) you told me in your message that it's good to change the first 2 preamp tubes - which ones ??? the first 2 from the right - looking at the rear of the amp ???

What kind of tubes you used ??? what brand ???

Thanks a lot, Marcian

 

[kaluablue]

Hi Marcian

Could be the effects loop of the .22
I had the same problem with my .22 . After cleaning the loop jacks everything was fine again. It's a known issue with the .22

Insert a patch cable to send /return and check if the problem still exists. I suppose it won't ;-)

 

[Lou]

Thanks a lot !

I need just few details if you it's ok for you to answer me...

1) What kind of EL84 you put inside ???(what brand ? what brand you recomend ??)

I saw that mine - that seems to be the original mesa tubes have the original label and other printed details pretty used - you can barelly see these details on the tube... So, can I conclude that these tubes are the original ones and are lifeless ???

2) you told me in your message that it's good to change the first 2 preamp tubes - which ones ??? the first 2 from the right - looking at the rear of the amp ???

What kind of tubes you used ??? what brand ???

Thanks a lot, Marcian

pre............2 furthest to the right when looking at the back of the amp.
I used tung-sol 12ax7's there...OK...
And........Mullard's reissue EL84's my amp just came to life after making these changes.

I'm going to try some electro-harmonix in the pre positions next.

 

[sugarblue]

Hello ! thanks ! today I'm gonna check everything and see the results !

I'll keep you informed if it works or not.

All the best ! Marcian

 

[Lou]

My name is Inigo Montoya.......................