amp problem...tube selection

[brit84]

Ok, my laney vc100 has a problem, I know its somthing with the tubes, symptoms:
-in and out volume, sometimes high to low and back, sometimes on and off
-high pitch squeel on gain channel
-whiney ringing noise in background, gets worse is a tap on the amp.

I replaced the preamps before the summer but then bought my genz so didnt really hear if they were microphonic. my poweramp tubes are about 3 yrs old now so i guss its about thier time, but are these symptoms poweramp related, the volume drops makes me think so.

can anyone suggest a good set of 5881/6l6 types?

 

[Baltar]

Re: amp problem...tube selection

hmm, do you still have the old preamp tubes somewhere?
if yes, i'd test every preamp tube - only one at the same time
(replace temporary with an old one that still works).

can't give any 6l6 suggestion, due to my old laney had 6v6
i've used ehx in that one. their tonal coloring fitted quite nice for my old aor

 

[Sleeping Martyr]

Re: amp problem...tube selection

Are 5881s and 6L6s the same?? sorry to hijack the thread

 

[Baltar]

Re: amp problem...tube selection

they are somehow electric compatible, as far as i know.
but they are different. people say 5881 are more smooth, more vintage.
my previous ampdoc told me not to change my thunder to use 6l6, this
would make a buzzsaw oft it.
but sound and taste is somthing individual.

 

[SonofaMitch]

Re: amp problem...tube selection

6L6 suggestions.....Groove Tubes, I love em, always worked and provided great tone for myself( still yet to try sovtek's tho)

 

[wixedmords]

Re: amp problem...tube selection

I am a big fan of Winged "C" 6L6's. They provide top end clarity and are pretty linear throughout. If I wanted to go a little darker I would go to JJ's 6L6's.

You can have a preamp tube that goes microphonic right out of the box. It would be worth purchasing one preamp tube and swapping them out one at a time to see if you find a bad one.

You will need to bias the map also.

 

[brit84]

Re: amp problem...tube selection

are these symptoms typical of power or preamp tubes though, as i recall, things started to go crappy before i changed the preamp tubes