#1
Just noticed a very audible hissing noise on turning up the master on my screamer, even on the clean channel...I didn't take any notice at first 'cause it sounds a bit like a heater of some description, and i thought it may be normal...however, on further thought i'm starting to think it may be dodgy tubes...

If anyone can clarify for me i'd be very grateful
id sig you but i have no room lol. so ill just bow down to your username

deg0ey
Member of UG Irish Clan: Póg mo thóin
#2
its normal for many amps to hiss a bit at high volumes, especially higher gain amps. Turn on your amp and gently tap the tips of your pre-amp tubes with a wooden stick and listen for a "bell-like" chime. This sound will mean your tube has gone microphonic and needs replacing. But remember, a slight hiss can be normal.
#3
I may upgrade them anyway, they still have the stock ones in...but yeah i'll try your test for microphonicness first
id sig you but i have no room lol. so ill just bow down to your username

deg0ey
Member of UG Irish Clan: Póg mo thóin
#5
if its a loud hiss its usually gonna be the preamp tubes...

mine was doing that to...30 bucks and 3 12ax7eh's later and it plays like a pro again.

you'd probably do good replacing the powertubes anyway...but don't spend the money if you don't want.
Quote by deg0ey
The best pickups for emo are no pickups at all...


Gear:

1996 Les Paul Classic w/ Alnico II's
Marshall Jubilee 2550
Avatar 2x12..V30 and G12H
Vox V847 Wah
Assorted pedals
#6
the stock tubes in ENGL amplifiers don't really need to be upgraded

I get a hiss on the high-gain channels of my powerball pretty much all the time. If you get a noise supressor it should clear it up no problemo, regardless weither or not your tubes are good/bad

Usually if they're bad its more than just a subtle hiss, its a very noticeable hiss and tons of feedback..
#7
Well, i took the back off and did the stick thing - the preamp tubes are fine...only thing is that one of the power amp tubes is glowing bright blue and the other isn't... That's bad right?

I took pictures, i'll upload them later when i can get on teh other pc
id sig you but i have no room lol. so ill just bow down to your username

deg0ey
Member of UG Irish Clan: Póg mo thóin
#8
wait a second...you said turnign up the volume on your screamer? you mean like a pedal you turn up is causing the hiss?

if oyu just plug into it clean is there a hiss?
Quote by deg0ey
The best pickups for emo are no pickups at all...


Gear:

1996 Les Paul Classic w/ Alnico II's
Marshall Jubilee 2550
Avatar 2x12..V30 and G12H
Vox V847 Wah
Assorted pedals
#9
well it's fairly loud with no guitar plugged in, master on 5 on the clean channel...
id sig you but i have no room lol. so ill just bow down to your username

deg0ey
Member of UG Irish Clan: Póg mo thóin
#11
if the tubes are burning at a different color then yeah, upload the pix for like seljer or geno to take a look at them...
#12
it's not amazingly clear in the picture, but you can see it...
id sig you but i have no room lol. so ill just bow down to your username

deg0ey
Member of UG Irish Clan: Póg mo thóin
#13
if your gettign a bad hiss with nothing plugged in its probably the preamp tubes....

and by bad hiss i mean really bad...so bad it hurts your ears almost...not just a low rumble.

the powertubes don't really cause a hiss when they go out...when they go out your amp my crack in and out for a minute...then it'll settle down and work still until they go completely dead.
Quote by deg0ey
The best pickups for emo are no pickups at all...


Gear:

1996 Les Paul Classic w/ Alnico II's
Marshall Jubilee 2550
Avatar 2x12..V30 and G12H
Vox V847 Wah
Assorted pedals
#14
ah ok, that's cool...it's not a painful hiss by any stretch it's just like...almost like when your radio can't find the station

The more i think about it, the more i think i'm overreacting... http://img11.picsplace.to/img.php?file=img10/9/DSCF0163.JPG that's the picture, you can see it's blue there - but it's probably normal (even though the other one's not nearly as blue)
id sig you but i have no room lol. so ill just bow down to your username

deg0ey
Member of UG Irish Clan: Póg mo thóin
#15
i couldnt really make out the picture..but ablue glow on the outside of the tube is fine
#17
Cool, it's not the clearest of pictures but ok it's probably fine and yeah it would make a cool album cover *thinks* maybe i'll keep hold of it
id sig you but i have no room lol. so ill just bow down to your username

deg0ey
Member of UG Irish Clan: Póg mo thóin