#1
I just retubed my Mesa preamp tubes. I put JJs in V1-4, V5 has a new mesa brand tube. The issue I am having is with the FX loop and also with the amp in general. I'm hoping this is an easy fix.
When I turn the amp on, let tubes warm, then play the sound that comes out is significantly quieter than before. The channels, in all modes, sound great, but just low in volume. For reference I have the volume on both channels at 12 and the master set at 12 and it is not even close to being loud enough. That is issue #1.

Number 2, is when I use the FX loop the amp sounds like there is crackling coming through. When I get the effects to work they are not as prominent sounding as in my Orange. When I engage my delay in the Mesa the volume decreases. This does not happen with my Orange. My FX chain does not have any issues through my Orange. The Mesa is the one with the issues.

Any guidance or things to try would be more than appreciated. I also wonder if issue with the FX is somehow related to the other amp issue, or vice versa. I know there are enough people to help guide me with whatever issue there may be, whether big or small.hanks guys.
Gibson LP traditional and DC standard, PRS S2 Custom 24, Schecter Banshee 7
EVH 5153, Mesa DR Tremoverb combo 2-2x12's
Line 6 M13
#2
It may just be a bad tube (even though its new). Have you tried swapping them out one by one?
Fender Mustang/Derfenstein DST> Boss Power Wah> Pedal Monsters Klone> Bogner Uberschall> Walrus Audio Janus> Randall RM20> Line 6 M9> Randall RM20
#3
I thought that as well at first. Would that explain the fx loop and the volume drop?

Is it safe to remove preamp tubes one by one while the amp is on but in standby?
Gibson LP traditional and DC standard, PRS S2 Custom 24, Schecter Banshee 7
EVH 5153, Mesa DR Tremoverb combo 2-2x12's
Line 6 M13
#4
I'm not sure. I'd just turn it completely off pick one and swap it (maybe use one the old tubes), see if that does anything, move to the next one etc. I'm certainly no amp tech though so I couldn't tell you anything else to try.
Fender Mustang/Derfenstein DST> Boss Power Wah> Pedal Monsters Klone> Bogner Uberschall> Walrus Audio Janus> Randall RM20> Line 6 M9> Randall RM20
#5
Logical progression. I'll give it a shot. Hopefully it's as simple as that. I didn't think any rebiasing needed to occur with Mesa, so I'll give the tube progression a chance. I'm still open to other ideas. Thanks so far, lucky.
Gibson LP traditional and DC standard, PRS S2 Custom 24, Schecter Banshee 7
EVH 5153, Mesa DR Tremoverb combo 2-2x12's
Line 6 M13
#6
Yes you can swap preamp tubes while the amp is on.

Not power tubes obviously.

Don't burn yourself

I do it all the time.

You can run the amp wide open with no preamp tubes FYI

What I don't know is if the loop is tube driven on the Single Rec

I don't think it is.

Try running you guitar into the FX return directly.

But yeah. Tube rolling is where it is at.

A new tube can be 'bad' or go microphonic quickly.

Crackling can be indicative of a microphonic tube.

So can pin arcing

Get some Dioxic contact cleaner and spray some on the pins

Never spray into sockets

Mesa amps are non adjustable fixed bias I believe.

No biasing necessary.

Welcome to the Single Rec club
#7
Thanks, 311. I'm glad to be in the club. I thought I remembered reading where you could remove tubes while the amp was on but in standby. This should expedite the process. I appreciate the suggestions. Nothing is more frustrating then wanting to go balls to the wall with a rec and not being able to.
Gibson LP traditional and DC standard, PRS S2 Custom 24, Schecter Banshee 7
EVH 5153, Mesa DR Tremoverb combo 2-2x12's
Line 6 M13
#8
^^ (311) Good to know, I always completely shut down my amp
Fender Mustang/Derfenstein DST> Boss Power Wah> Pedal Monsters Klone> Bogner Uberschall> Walrus Audio Janus> Randall RM20> Line 6 M9> Randall RM20
Last edited by lucky1978 at Jun 6, 2014,
#9
What will running the guitar directly into the FX return do? I do have effects that I run through the loop, won't running the guitar directly into that negate the loop? Or is this to figure something out, which I presume it is?
Gibson LP traditional and DC standard, PRS S2 Custom 24, Schecter Banshee 7
EVH 5153, Mesa DR Tremoverb combo 2-2x12's
Line 6 M13
#10
Quote by bobafettacheese
What will running the guitar directly into the FX return do? I do have effects that I run through the loop, won't running the guitar directly into that negate the loop? Or is this to figure something out, which I presume it is?



if you run it into the effect loop and the problem goes away it means your problem is in the preamp section of the amp(most likely tubes)
#11
Ok, and I what if this is not the issue and the problem still exists. Too late at night to test that now, will go for broke in the morning. Just trying to find the correct steps to take.
Gibson LP traditional and DC standard, PRS S2 Custom 24, Schecter Banshee 7
EVH 5153, Mesa DR Tremoverb combo 2-2x12's
Line 6 M13
#12
Tried going directly into the fx return and there was very little to no noise coming through. I tried the one by one tube replacement with a tube I knew worked and it did not solve anything. The amp works and all channels produce the sound they should, it is just really restricted. I have to have the master at 12 just to get it loud enough. I know this is not how it should be. Any further guidance would be great.

Could it be the power tubes?
Gibson LP traditional and DC standard, PRS S2 Custom 24, Schecter Banshee 7
EVH 5153, Mesa DR Tremoverb combo 2-2x12's
Line 6 M13
#13
Easily could be power tubes for the volume concern.

I can't remember much about the FX loop on the rec series. I thought it was parallel?
Quote by DeathByDestroyr
See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.
#14
I was planning on ordering more JJs just to have on hand anyway. I will order some power tubes to be safe. The thing that bothers me is that the fx was acting up prior to the retube, which is why I went for the retube anyway. Now the volume loss has me further perplexed. The volume loss was not apparent prior to the swap. I'm not suspecting anything major, I'm just perplexed and well, frustrated.
I do appreciate the help, though.
Gibson LP traditional and DC standard, PRS S2 Custom 24, Schecter Banshee 7
EVH 5153, Mesa DR Tremoverb combo 2-2x12's
Line 6 M13
#15
Any chance you bumped a power tube out of place while changing the preamp? Have you tried reseating the power amp tubes?
Quote by DeathByDestroyr
See, it's important that people clarify when they say "metal", because I pretty much always assume they are a Cannibal Corpse fanboi.