#1
Hello all that know more than me!!

Having some amp problems (Laney Gh50L), I suspect tube troubles, maybe the pre amp ones.
Guitar is plenty loud = power tube probably ok (EL34)
Just had the pots cleaned = not them, they were bad and making it worse but problem persists

When on clean the tone is pretty good, however when I turn on the boost setting (distortion channel) it makes plenty noise and that but it sounds very fuzzy and muddy.
Example: Hit a power chord and let it ring, as the sound fades muddy fuzzy crackles clearly heard

Am I right in my assumption that its the pre-amp tubes (ECC83)? Im hoping its not the cab or anything more serious.

If so? Any advice on what ones to get? Looking at older threads JJ's are often recommended.

Thanks
07 Gibson Les Paul LE
06 Fender Mex Strat - SDJb Jr, duckbucker, lil 59
Floor
Cry Baby 95Q-> Digitech Whammy -> DD3 -> MXR Micro Amp-> TU 2
Loop
Holy Grail ->Boss Rc20 Loop Station
Amp
Laney GH50 with Zilla Fatboy 2x12 (celestion g12-65)
#2
Anyone?
07 Gibson Les Paul LE
06 Fender Mex Strat - SDJb Jr, duckbucker, lil 59
Floor
Cry Baby 95Q-> Digitech Whammy -> DD3 -> MXR Micro Amp-> TU 2
Loop
Holy Grail ->Boss Rc20 Loop Station
Amp
Laney GH50 with Zilla Fatboy 2x12 (celestion g12-65)
#3
For me, crackling after notes is usually a microphonic tube. Something has come loose in the tube and is shaking around and transferring that noise to the output stage.
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#4
Buy at least one good 12AX7, preferrably two or three. For that thing you'll want JJ ECC83S. Try the new tubes in different spots until you locate the dodgey tube. You should always have spares, a full set of power tubes and at least one spare preamp tube.
Also try cleaning the sockets. Spray a bit of contact cleaner on the tube pins and work it in and out of the socket a few times.
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#5
"Buy at least one good 12AX7" - can you explain that please Cathbard?

I got a technician to clean the pots and serice it, Im pretty pissed that he didnt try it out and see that the amp was not sounding ok in both channels before giving it back to me. He cahrged me 50euro just to clean the pots as far as I can tell.

When cleaning sockets. A quick spray and a wipe with a cloth or cotton bud ok or is there a specific way I should go about it?

Thanks for the sound advice on the spares too.
07 Gibson Les Paul LE
06 Fender Mex Strat - SDJb Jr, duckbucker, lil 59
Floor
Cry Baby 95Q-> Digitech Whammy -> DD3 -> MXR Micro Amp-> TU 2
Loop
Holy Grail ->Boss Rc20 Loop Station
Amp
Laney GH50 with Zilla Fatboy 2x12 (celestion g12-65)
Last edited by gerrywm at Nov 19, 2011,
#6
Quote by Reincaster
For me, crackling after notes is usually a microphonic tube. Something has come loose in the tube and is shaking around and transferring that noise to the output stage.


Does microphonic mean that the tube is basicall dead and has to go? Or does it just need to wiggled a bit to get it to click back into place?
07 Gibson Les Paul LE
06 Fender Mex Strat - SDJb Jr, duckbucker, lil 59
Floor
Cry Baby 95Q-> Digitech Whammy -> DD3 -> MXR Micro Amp-> TU 2
Loop
Holy Grail ->Boss Rc20 Loop Station
Amp
Laney GH50 with Zilla Fatboy 2x12 (celestion g12-65)
#7
Quote by gerrywm
Does microphonic mean that the tube is basicall dead and has to go? Or does it just need to wiggled a bit to get it to click back into place?

If a tube is microphonic it's basically borked, it will need replacing.
*Edit* That said, a loose tube does rattle. If you reseat it and it still gives you noise problems, then it's the tube that has developed a fault.
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#8
Quote by Cathbard
Buy at least one good 12AX7, preferrably two or three. For that thing you'll want JJ ECC83S. Try the new tubes in different spots until you locate the dodgey tube. You should always have spares, a full set of power tubes and at least one spare preamp tube.
Also try cleaning the sockets. Spray a bit of contact cleaner on the tube pins and work it in and out of the socket a few times.

This sums it up nicely.


Quote by gerrywm
"Buy at least one good 12AX7" - can you explain that please Cathbard?

I got a technician to clean the pots and serice it, Im pretty pissed that he didnt try it out and see that the amp was not sounding ok in both channels before giving it back to me. He cahrged me 50euro just to clean the pots as far as I can tell.

When cleaning sockets. A quick spray and a wipe with a cloth or cotton bud ok or is there a specific way I should go about it?

Thanks for the sound advice on the spares too.

A 12AX7 (sometimes referred to as ECC83) is the type of tube your amp runs in it's preamp. You have at least one faulty tube, so you'll need at least one spare, but it's better to have plenty of spares, and they don't cost too much, so better stock up. As Cath said, JJ tubes sound nice in the GH.

As for cleaning, plug a tube in and out of the socket a couple of times. Contact cleaner helps, a cloth is not needed.


Quote by gerrywm
Does microphonic mean that the tube is basicall dead and has to go? Or does it just need to wiggled a bit to get it to click back into place?

It needs to go.
#9
Quote by TheQuailman
This sums it up nicely.


A 12AX7 (sometimes referred to as ECC83) is the type of tube your amp runs in it's preamp. You have at least one faulty tube, so you'll need at least one spare, but it's better to have plenty of spares, and they don't cost too much, so better stock up. As Cath said, JJ tubes sound nice in the GH.

As for cleaning, plug a tube in and out of the socket a couple of times. Contact cleaner helps, a cloth is not needed.


It needs to go.


Thanks very much, that was a great clear reply.

Thank you to everyone else too!
07 Gibson Les Paul LE
06 Fender Mex Strat - SDJb Jr, duckbucker, lil 59
Floor
Cry Baby 95Q-> Digitech Whammy -> DD3 -> MXR Micro Amp-> TU 2
Loop
Holy Grail ->Boss Rc20 Loop Station
Amp
Laney GH50 with Zilla Fatboy 2x12 (celestion g12-65)