do i need to bias my 5150 for a re-tube?

[Incognito Man]

its time for new tubes in my 5150 and i have never done this before so i dont know much about it.

do i need to bias the head or can i just put the tubes in and be on my way?

on the eurotubes site it says the tube kit is "plug and play" so i assume this means i do not need to bias.

also it says to put a speific tube in "v1" what position is v1?

the head is an older model with eddies signature on the back and it just says "EVH" in bold black letters on the front.

thanks!

 

[greyskull]

5150s unless modded are fixed Bias... so no.

 

[Incognito Man]

awesome! then i dont need to pay a tech and have downtime.

 

[Incognito Man]

i just found this info on the net so perhaps i will have to take it in.



"Fixed bias does not mean that the amp "biases itself". It means that the voltage to bias the amp is a fixed one, which is usually adjustable (or, should be) so that the amp can be biased properly for each new set of tubes"

 

[Wohma]

V1 is a position in the preamp (12AX7 tubes, the smaller ones). These can be changed without any adjustments. Replacing power tubes usually requires settings the bias. Although you theoretically could just swap the tubes and play without problems, you could also fry not only the tubes, but potentially also some parts of the amp - and you probably don't want to do that. If you're investing into complete retubing, add a few more bucks and have someone reliable and experienced do that. Better safe than sorry.

 

[TheWinterSnow]

5150s unless modded are fixed Bias... so no.

That's not what fixed bias means.

EDIT: I got beat to the punchline.

i just found this info on the net so perhaps i will have to take it in.

"Fixed bias does not mean that the amp "biases itself". It means that the voltage to bias the amp is a fixed one, which is usually adjustable (or, should be) so that the amp can be biased properly for each new set of tubes"

5150s are biased extremely cold and are not adjustable without a mod, so unless you want to pay for a bias mod (or you can DIY) then you don't need to worry about it. FWIW, I did the bias mod on mine, but its not something everyone likes.

 

[acappa]

Peaveys amps are biased cold, at least XXX and 6505. Is the 6505 II fixed bias too??? I need to retube very soon...

 

[acappa]

maskedman72

Are you retubing the same way as the standar? 5x12AX7 + 4x6L6 ?? May be I´m trying some KT77...

 

[TheWinterSnow]

Peaveys amps are biased cold, at least XXX and 6505. Is the 6505 II fixed bias too??? I need to retube very soon...

All high gain metal amps have fixed biased power amps.

Are you retubing the same way as the standar? 5x12AX7 + 4x6L6 ?? May be I´m trying some KT77...

Wouldn't recommend anything other than 6L6s unless you want your amp to die on you.

 

[stilllifer]

also it says to put a speific tube in "v1" what position is v1?

V1 preamp is usually the closest one to the input.

 

[Damage, Inc.]

Bob from Eurotubes recommends fairly hot tubes to offset the cold bias of amps like Mesa and Peavey. Your tube life will be somewhat shorter than the stock ones, but your amp should sound better. You're not going to hurt the amp by doing this. Remember that fixed bias means there is either a resistor or a pot that sets the bias. For the 5150, setting the bias means swapping the resistor...not worth the effort if you have the right tubes.

 

[bryan_kilco]

I semi-recently swapped out Groove Tubes (power) and Sovtek (pre) from my Mesa Mark IV and replaced them with a Doug's Tubes set of Ruby 6L6/EL34 and the 12ax7 preamp kit. This retube made the amp SOOOO much LOUDER!! I can barely push it to 2 on the master volume without drowning out the band.

 

[Incognito Man]

now i am confused, do i need to take the amp in for a re-tube/bias or can i just pop the new tubes in myself?

i am going to get a tube kit from this page, im not sure what kit yet though.
https://ssl.eurotubes.com/cart/index.php?page=view_products&category_id=8&sub_category_id=40

 

[bryan_kilco]

If it makes you feel any better, our other guitarist retubed his Recto with a High Gain kit from Eurotubes and he didnt re-bias. I retubed my Mark IV and didnt get it biased. They claimed the tubes were picked based on the type of amp you use......

 

[CraigCabana73]

All high gain metal amps have fixed biased power amps.



Wouldn't recommend anything other than 6L6s unless you want your amp to die on you.

 

[atoragon]

that's not exactly true, there are some in which you can use different power tubes and they will set the bias accordingly, such as the hughes and kettner switchblade, coreblade etc

 

[jaap versluis]

hi all, I just joined this page. I have a brand new EVH 5150III 6L6 50W combo and after a few weeks the phase tube broke and 1 power tube. I got a new pair of TubeAmpDocter 6L6GCM-STR REDBASE premium matched pair, can I just put the tubes in or need to set the bias? I am confused about answer's about the bias. on the box of the new pair is say PC:43 on both tubes, I think that is the setting of the tubes. what do I need to do? put the tubes in and play or bring it to service? advice?

 

[Machinated]

hi all, I just joined this page. I have a brand new EVH 5150III 6L6 50W combo and after a few weeks the phase tube broke and 1 power tube. I got a new pair of TubeAmpDocter 6L6GCM-STR REDBASE premium matched pair, can I just put the tubes in or need to set the bias? I am confused about answer's about the bias. on the box of the new pair is say PC:43 on both tubes, I think that is the setting of the tubes. what do I need to do? put the tubes in and play or bring it to service? advice?

put the valves in, keep a eye on them once you power on. If they’re not red plating after a few minutes, you’ll probably be OK.

That said, for optimal tone and longevity of the valves (and amp), you should definitely have the amp biased by a tech. It’s generally worth having them give it a once over as it could be something else that caused the tubes to go (and therefore could happen straight away again if it’s not fixed).

 

[jaap versluis]

put the valves in, keep a eye on them once you power on. If they’re not red plating after a few minutes, you’ll probably be OK.

That said, for optimal tone and longevity of the valves (and amp), you should definitely have the amp biased by a tech. It’s generally worth having them give it a once over as it could be something else that caused the tubes to go (and therefore could happen straight away again if it’s not fixed).

Ok thanks for your replay and i am
Looking in my area if there is a shop who can bias the amp. Thanks again