#1
I have a peavey 6505 and i want to replace the stock tubes to give a better sound

can i just buy some JJ/telsa valve of the same model and put them in or would i need to re-bias the amp?
GUITARS:
Jackson SLS3
Ibanez ART120 w/ Duncans
AMPS:
ENGL Fireball
PEDALS:
Boss NS-2
MXR ZW-44
TC Polytune
Digitech Drop pedal

My band: www.facebook.com/deifieduk
(actually called Deified)
#2
I thought someone might give you more information here. I guess not.

Here are some things to take into account:
1. You don't necessarily have to re-bias the amp. Some amps can't be re-biased, some bias themselves. If you are able to re-bias the amp, you may get a better sound if you do it.
2. Follow this link for helpful information - http://thetubestore.com/powertubeinfo.html
3. Be careful not to shock yourself. Tubes store a lot of power in themselves.
4. I don't believe the 6505 has an adjustable bias, but you'd have to check the manual. There is however a mod to give you that functionality.
#3
^"Don't shock yourself" is a bit of an understatement...

More like "Don't KILL yourself". Tubes themselves don't store any voltage, but their plate voltages are usually a couple hundred volts AC or more, which could kill you. You'll need to let the caps drain. This could take anywhere from 5 to 30 minutes and sometimes quite a bit longer. IDR the formula for caculating the time it'd take for them to drain, so I'd leave it off and unplugged for 24 hours. Then it'll definately be safe to work on.

I know nothing about that particular amp, but what I just said applies to all tube amps.
#4
Quote by Invader Jim
^"Don't shock yourself" is a bit of an understatement...

More like "Don't KILL yourself". Tubes themselves don't store any voltage, but their plate voltages are usually a couple hundred volts AC or more, which could kill you. You'll need to let the caps drain. This could take anywhere from 5 to 30 minutes and sometimes quite a bit longer. IDR the formula for caculating the time it'd take for them to drain, so I'd leave it off and unplugged for 24 hours. Then it'll definately be safe to work on.

I know nothing about that particular amp, but what I just said applies to all tube amps.

DC..

After the rectifier all voltages are DC. Hardly any high AC voltages in amps (besides coming off PT secondary.)
There are AC signals though, your guitar signal

If you have no way of draining the caps their charge can be there for months, much longer than 5-30min.

If you got a bleeder resistor the caps discharge pretty quickly. My Vibro Champ has a huge resistor (1M) to bleed and it only takes 1.26min or something.
#5
Quote by Invader Jim
^"Don't shock yourself" is a bit of an understatement...

More like "Don't KILL yourself". Tubes themselves don't store any voltage, but their plate voltages are usually a couple hundred volts AC or more, which could kill you. You'll need to let the caps drain. This could take anywhere from 5 to 30 minutes and sometimes quite a bit longer. IDR the formula for caculating the time it'd take for them to drain, so I'd leave it off and unplugged for 24 hours. Then it'll definately be safe to work on.

I know nothing about that particular amp, but what I just said applies to all tube amps.


Dude,
This is extremely dangerous advice to be giving out when you clearly haven't a clue what you're talking about.
As Kurt pointed out the plate has high DC voltage.
Filter caps can store charge for years, especially if a fault has caused a break in the discharge path.
There is definitley no way you can say just turing of an amp for 24 hours makes it safe, someone could get seriously hurt following this kind of stupid advise.
Please refrain from giving tube amp advise in future.
#7
Quote by Invader Jim
Didn't have to be a dick about it, man.


Giving flagrant, ill-advised advise like this could cause someone serious harm. How would you feel if someone got badly injured because they thought it was safe to go poking in their tube amp after just turning it off for 24 hours?
I do apologise if it seemed like I was be-littling you though, I hadn't intended to come across derogatory. It's great that your taking an interest in electronics and want to learn but perhaps it would be best to wait until you know more before advising others.
#8
You did sound be-littling and derogatory. I don't know alot about tubes, but I thought I knew enough to try to warn TS. Been doing this since I was 8. I thought I was getting good at it, too.

Eh. Apology accepted.
#9
paolojm thanks for advising me about the dangers is there any way of getting the charge out of the power and pre amp tubes before i replace them?
GUITARS:
Jackson SLS3
Ibanez ART120 w/ Duncans
AMPS:
ENGL Fireball
PEDALS:
Boss NS-2
MXR ZW-44
TC Polytune
Digitech Drop pedal

My band: www.facebook.com/deifieduk
(actually called Deified)