My Tremoverb died last night (help diagnosing please)

[mbmesa]

I was playing at LOUD jam with my Tremoverb Combo and all of a sudden the signal started getting staticky and cutting out. Sounded like blown speakers but I am pretty sure its not because it sometimes works and sometimes doesn't (gets statick and the signal cuts in and out , especially on loud chord hits). The signal never really cuts out totally, it just gets very quiet and then loud and then quiet again with lots of static in between.

I checked the tubes and they are all glowing and properly seated. I tapped the preamp tubes looking for microphonic ones but they checked out fine. The amp is all original including the tubes.

Is this a common symptom in these amps after 15 years or so ? My first instinct is a retube or at least swap tubes with a spare one by one but what else can I try ? So far I have played with all the switches ( bold , spongy, tube/solid rectifier, effects loop bypass etc) the staticky and cutting out sound is on all channels and modes.

So far the amp has been bullet proof for the whole time I've owned it since new. It even survived a fall from a minivan hatch onto the pavement a few years ago with no issues.

Any suggestions would be appreciated.

 

[Elpelotero]

how old are the tubes?...both the preamp and power and rectifier? try asking a friend to loan you a spare set to test out on your amp.

 

[mbmesa]

The tubes are the originals. I have not played the amp regularly until the past couple of years. I will do a retube for sure but I need to get the amp going now before the tubes come in so I will borrow a few. What about the fixed bias issue ? If I take the sovteks out of my Fender amp and try them in the Tremoverb, I could fry them if the bias requirements are severely different ?

 

[dennq45]

No worries... Pre-amp tubes in all amps are self biasing. In Boogies, the Power Tubes self bias also.

 

[mbmesa]

Self-Biasing power tubes ? Cool. I thought they were fixed bias thereby requiring a careful selection of power tubes to match the fixed bias.

So for my static and cutting out to low volume and then high volume problem, if its not the tubes, what else can it be ? I ruled out the speakers, cables , guitars etc so far. By this afternoon I will have the tubes tested , what would be the next step ? Pull the chassis,discharge the filter caps and look for lose connections ?

 

[Elpelotero]

tubes can not self-bias....Mesas have a fixed bias, meaning you have to buy tubes with a bias that fall within the range specified by Mesa. If you buy tubes that fall outside this range, you run the risk of either frying the tubes quickly or damaging the inside components of the amp.


If you have not bought new tubes since you got the amp, and have had the amp for several years, the amp failure must be due to the old tubes. Mesas rarely malfunction in a way other than tube failure.

Before trying your Fender Sovteks, assert that they have a color coding or bias range in line with Mesa's. I would wait unitl tomorrow and call the office to ask if it would be safe. I am not sure what the bias range is for a tremoverb, unless you have a tester.

 

[macmax]

i think that what is wrong with your amp is the LDR, or something like that it is called.

Call Mesa , they will truly help you,

Take good care and Good Luck

 

[TremoFan]

tubes do not self bias nor due the amps

 

[4nkam]

I would definitely have a mesa tech check it out. The Tverbs suffer from a few problems direct from the factory and they usually show up over time. Whenever they do get a tverb in the shop, they perform the needed upgrades/corrections so you're good to go again.

mJ

 

[mbmesa]

Is there a list somewhere of upgrades/corrections available for the T-Verb ? I have one of the earlier ones and I have had it since new.

 

[4nkam]

I don't think so. I could check my receipt from boogie and see if they mention specifics but it's mainly various LDRs and resistors.

mJ