**UPDATE** Channel 1 on my T-verb just crapped out??

[tele_jas]

Last night we set up and did our line checks and my amp sounded fine on both channels...... Then we did our sound-check song and I was on channel one (set for clean) and all of a sudden it started fading in and out. almost like the Tremolo, but not in time. I switched to channel 2 (Vintage) and it sounded fine, and then back to ch 1 and it was getting worse and more sparse and VERY unusable! But, ch 2 was fine???????

I looked at all the power tubes and they all looked fine, I then wiggeled all the preamp tubes and they were fine (I figure it would affect both channels if a preamp or poweramp tube was the cause)... I switched all my switches and removed all channel switching pedals and it still did the same thing on channel 1 (clean and blues).

The first time in 8 years I didn't take a back-up and my amp goes out.... I ended up dialing in the in the cleanest sound I could possibly get out of channel 2 and using my V-twin for my main distortion, it sounded very compressed and thin but it got me by.

I took my chassis out this morning and looked, for what I don't know, and sprayed some pot cleaner in a few places and tried it again and it was still doing it.

Anyone know what this could be? I'm taking it to a repair man Monday, but I was hoping not to have to spend the $75+ on repairs if it's a simple fix.

 

[RussB]

Try swapping the pre-amp tube that affects the clean channel...

 

[tele_jas]

Not to sound stupid, but I looked at the tube chart in the manual and I don't see which one that is??

V1 A= 1st input/gain stage
V1 B= reverb return
V2a = 2nd gain stage
v2 b= 3rd gain stage
v3 a= 4th gain stage
v3 b= 5th gain stage
v4 a= FX retun amp
v4 b= FX send buffer
V5 a= reverb driver
v5 b= reverb master
v6 a= phase splitter /
>
v6 b= output

This is what they have listed in the manual, I dont see which tube?

 

[RussB]

Hmmm, I see what you're saying...

I would still try putting a good tube in V1, V2, and V3 just to see what (if anything) happens...

 

[cnumb44]

I'm with Russ B. If you have 3 spares, swap all three one at a time. If you have one good spare, the do it one at a time. If you don't have any spare then swap 1 and 2 and see if the problem follows the tube. That might be a good starting point anyway just to see if it is that first tube.

 

[tele_jas]

I replaced the V1 tube that first night with a brand new JJ 12ax7 and it still did it. I have 2 more tubes (the one I took out plus another one), I'll try swapping around tonight and see if that takes care of it. Thanks

 

[4nkam]

Is everything else (as far as you know) in good shape? Screen grid resistors are still ok?

MJ

 

[tele_jas]

Is everything else (as far as you know) in good shape? Screen grid resistors are still ok?

As far as I know?? I've used it for the last 15 shows with no problems and then all of a sudden in the middle of our sound-check song it started going out. I'm not a repair tech or even really know the first thing about repairing amps, but it worked fine before the other night.

 

[tele_jas]

Well, I woke up early this mornig (before I had to go to work) and set up my t-verb and tried new tubes in the V1 (again), V2, and V3 socketts and it still did the sparatic drop out thing on channle 1.

Looks like it's going to the repair shop this afternoon and it usually takes about 2 months to get stuff back from him unless you say you need it faster and then he charges a "STAT" fee of $50 - $100 extra. The only thing that may save me is that he's not only the only certified Mesa repair man in the area, but he's also our soundman and he knows that is my main amp so he may do me a favor and move it to the top of his list.

I'll post what he finds is wrong with it.

 

[Michael]

My repaire man does mine in like 2 days LOL, my amps not under warrenty and F#*&$ i dunno where in Australia you would go to find a mesa technicion, theres only one shop inthis county that actully imports them, hmmmm find out what valve amp technicians music shops use near you find his name then give him a call and see how long it will take him.
Thats my only thoughts on how you coudl make it quicker, music shops here near my area all use one guy for there Valve amp customers, and he managed to do mine over the weekend (fix a wireing problem it jsut cut out and wouldn't turn on the lights were all on but no sound, and replace all the valves apart from teh 4 6l6's) he obviously has a heavy load doing all the music shops aroudn here to so my thought Tel is just ring around, but be carfully you dont' get some young Punk taking over his daddies business. LOL

Good luck budy
Michael

 

[Sanchez]

Michael.

The Mesa Warrenty tech is in Perth but if not under warrenty I'd take it to John at Pro audio in a flash. He is the biggest valve amp fanatic I've ever met and has about 30 different Marshalls, Hiwats, Fenders, Mesa's etc. He is THE man to fix ANY valve amp.

I've been very lucky with my Fender Prosonic. So far the only time it has ever had to see a tech was once for a retube and bias adjustment. Maybe that says something about it's build quality!!!!! It was built in 1999.

Sanchez

 

[Michael]

Thanks i'll keep that in mind.
Lucky it isnt' uder warrenty, Perth LOL that woudl be a treck and a half LOL
Thanks
Michael

 

[tele_jas]

Huh...... I put an email in to Voodoo amp to see about moding my T-verb once I got it fixed and they said something in their reply that might be related to my problem......

Unfortunately the Tremoverbs have a screen grid resistor that is burning up
on one of the power tubes. Also there is a resistor in the low voltage
supply that is also burning up. Eventually the volume/audio will begin to
cut in/out. Amplifier repair technicians seem to want to blame the mods for this failure, so to avoid all of this we have chosen not to mod the Tremoverbs any
longer.

Mine hasn't been modded, but this sounds like what my amp is doing..... Very interesting :?: I'll have to pass this on to my repair guy to check this out first.

 

[boogieslide]

tele_jas,
Voodoo modding Mesas came up in a thread over on HC and I asked Trace about the No Mod on Tverbs thing. Same response, but the way he said it there made me believe that with a little extra $$ and some understanding of the situation.....they will do some mods to them. They will replace those parts that have had inherent problems first (that's where you need the extra cash). Then they will do the mods.
I am only about an hour and a half from their shop and have toyed with the idea of at least having them swap out those resistors for reliabilities sake.

 

[4nkam]

Yep, that's what I was mentioning earlier, the screen grid resistors. It's not the user's fault, it's just that way from mesa and it happens.

MJ

 

[desdinova]

Hey tele_jas, hows ur tremoverb? got it fixed yet? if yes, where is the problem as mine crapped out just like urs.

 

[tele_jas]

No, I haven't got it back yet...... As of Friday, the repair guy had not even looked at it yet. As soon as I find out whats wrong with mine, I'll post a reply or PM you with what I found out, and if you get your's fixed before mine please let me know what you found out. Thanks and good luck!

 

[tele_jas]

****UPDATE****

Ok, my repair guy just called and said he's been working on my amp for 2 hours today and may have found the problem. It's a LDR, I think he called it a Light Dependant Resistor but not sure.... It has to do with the channel switching. He said that newer boogies use a different switching method, which is more reliable but also has it's drawbacks - a pop when switching channels. The other good news it it's a $5 part, so for the entire repair it's gonna be $80 with labor.

He found it by using the Heat/Cold method (soldering iron and a can of freeze spray). So just to be sure it's not going to flake out, he left it turned on and is going to lunch and to run some errands for a couple of hours and then come back and check it again. If all's good, he's putting it back together and I'm picking it up in a few hours and using it tonight!

I'll let you know how it goes!

 

[4nkam]

Oh that's right! Mesa upgraded mine too when I had it in for repairs, I wasn't sure what it was at first though.

MJ

 

[tele_jas]

IT WORKED!!!!!! I played 2 four hour shows with it (5 or 6 hours with sound check and messing around before hand) and it didn't mess up one time!! Whew!!!!!!!!!!!!!!!!!