Go Back   UG Community @ Ultimate-Guitar.Com > Instruments > Guitar Gear & Accessories
User Name  
Password
Search:

Reply
Old 09-16-2012, 04:00 PM   #1
AsOneIStand
Registered User
 
Join Date: Feb 2010
Retubing 6505+

So I have a 6505+ and I'm pretty sure it still has stock tubes in it, and I was wondering if since it has a fixed bias if I can use the same type of tubes (pretty sure they are 6l6's) but by a different brand and be safe and if so, what tubes are good ones to use?

If tubes affect sound, the main bands I listen to are Trivium, Machine Head, and In Flames (hence the main reasons I got this amp)
AsOneIStand is offline   Reply With Quote
Old 09-16-2012, 04:17 PM   #2
Tremolo Bum
Addicted to FR
 
Tremolo Bum's Avatar
 
Join Date: Feb 2008
As long as you get a matched quad or 2 matched pairs of 6L6GC tubes your good to go. No biasing required for this amp.

JJ tubes go well with these amps. The stock sovteks were a bit bright but the preamp is where most of the tone comes from so don't expect a huge difference.

Last edited by Tremolo Bum : 09-16-2012 at 04:18 PM.
Tremolo Bum is offline   Reply With Quote
Old 09-16-2012, 04:51 PM   #3
R45VT
Doesn't speak guitar
 
Join Date: Dec 2009
Location: Traffic Town LA
^^wrong to an extent, there is an adjustment on +

Ok, if you have a head then you can bias. The bias adjustment isn't too great of a swing so you can't burn'em out like on other amps. A popular mod is to change this for better adjustability.

112 combo, no bias.

Also V1 has the most impact on overall tone. You can play around with different types. JJs throughout the rest IMO.

Last edited by R45VT : 09-16-2012 at 06:30 PM.
R45VT is offline   Reply With Quote
Old 09-16-2012, 04:55 PM   #4
AsOneIStand
Registered User
 
Join Date: Feb 2010
Quote:
Originally Posted by R45VT
^^wrong

Ok, if you have a head then you can bias. The bias adjustment isn't too great of a swing so you can't burn'em out like on other amps. A popular mod is to change this for better adjustability.

112 combo, no bias.


Sorry. Then in that case, if I buy the same type of tubes, do I need to bias?
AsOneIStand is offline   Reply With Quote
Old 09-16-2012, 04:58 PM   #5
R45VT
Doesn't speak guitar
 
Join Date: Dec 2009
Location: Traffic Town LA
Combo or head????
R45VT is offline   Reply With Quote
Old 09-16-2012, 04:58 PM   #6
AsOneIStand
Registered User
 
Join Date: Feb 2010
Head
AsOneIStand is offline   Reply With Quote
Old 09-16-2012, 05:03 PM   #7
R45VT
Doesn't speak guitar
 
Join Date: Dec 2009
Location: Traffic Town LA
Personally I would bias it to get the most out of the tubes, even stock. You could drop new tubes in and most likely be ok.


Edit- there are also bias probes on the back of your amp. It can be checked with a volt-meter there. Very important to note DO NOT USE your meter on AMPERAGE setting. You can totally screw up your amp and tubes. This seems to be a big concern from googling bias on the +. It looks like guys were saying -55 puts it out of cross over, however stock you will not get it out of that. If you don't feel comfortable then don't mess with it. In stock form your not going to hurt anything as its pretty cold.

Last edited by R45VT : 09-16-2012 at 06:13 PM.
R45VT is offline   Reply With Quote
Old 09-16-2012, 05:44 PM   #8
KailM
Registered User
 
KailM's Avatar
 
Join Date: Feb 2011
Now I have the 112 combo, so it might be a little different than the head, but with mine, a preamp upgrade made a lot bigger difference than changing the power tubes.

I put all JJs in my preamp and it made it sound richer and a little darker. A short while later I put two new JJ 6L6s in and it made a little difference but not huge.

It's also fun to play around with a lower-gain preamp tube like a 12AT7. I've got a JJ one in my phase inverter position. Running it that way it smooths out some of the top-end fizziness and makes the rhythm w/ crunch channel more mellow for more versatility. The lead channel is still brutal as F@!@, but requires a little less preamp gain to do so. I've also tried that tube in V1 and it's a similar effect.
__________________
Schecter Blackjack ATX V-1
Peavey 6505+ 112 "head"/Crate 412 cab w/ Eminence Governors/Swamp Thangs
TC Elec. Hall of Fame 'Verb/Flashback Dly
Ibanez TS-9/MXR 10-band EQ
Boss HM-2
KailM is online now   Reply With Quote
Old 09-16-2012, 08:56 PM   #9
Tremolo Bum
Addicted to FR
 
Tremolo Bum's Avatar
 
Join Date: Feb 2008
Quote:
Originally Posted by R45VT
^^wrong to an extent, there is an adjustment on +

Ok, if you have a head then you can bias. The bias adjustment isn't too great of a swing so you can't burn'em out like on other amps. A popular mod is to change this for better adjustability.

112 combo, no bias.

Also V1 has the most impact on overall tone. You can play around with different types. JJs throughout the rest IMO.


Nothing I posted was wrong. The 6505+ head does not need to be re-biased with new power tubes. I own one and replaced the tubes recently.

I'm just going to copy and paste a post I made in a previous thread so as to not retype it.


Quote:
Originally Posted by Tremolo Bum
In a nutshell:

6505+'s do have an adjustable bias, but unless the amp is modded, it is pretty much unusable. With a stock 6505+, the bias cannot be set hot enough to damage anything. You will be fine just throwing your new tubes in without biasing them, as long as they are matched pairs or a matched quad.


In more detail:

On the 6505+ model, there is a bias adjustment pot inside the amp next to the tubes. However, these amps are biased extremely cold from the factory. I checked the bias on mine and it was only running at 17 mA even with the bias adjustment up as high as I could go. For 6l6GC's this is quite cold.

The thing is, you can't really hurt your amp if it's biased too cold. It will just sound cold, sterile, and you will have crossover distortion. If the amp is biased way to hot, you could blow the tubes.

With the 6505+, the bias pot's range is so small, you can't really even properly bias the amp unless it is modded. Even if you turn the knob for maximum current, you won't really be able to get much more than 18mA, which is far less than what would damage those tubes, assuming no defects. The sweet spot for 6505's tends to be in the 30mA range.

There is a bias mod that can be done to the 6505+ which is simply replacing a resistor in the bias circuit with a different one to give the bias pot more range. This allows the amp to be biased up into the higher current ranges.
Tremolo Bum is offline   Reply With Quote
Old 09-16-2012, 09:04 PM   #10
R45VT
Doesn't speak guitar
 
Join Date: Dec 2009
Location: Traffic Town LA
Quote:
Originally Posted by Tremolo Bum
Nothing I posted was wrong. The 6505+ head does not need to be re-biased with new power tubes. I own one and replaced the tubes recently.

I'm just going to copy and paste a post I made in a previous thread so as to not retype it.


Next time say there is an adjustment but it won't do shit.

I thought I remembered you posting that last time.

Just might be a little misleading for someone.

And thank for posting the mA values. Goes to show how cold they are.

Last edited by R45VT : 09-16-2012 at 09:05 PM.
R45VT is offline   Reply With Quote
Old 09-16-2012, 09:06 PM   #11
Tremolo Bum
Addicted to FR
 
Tremolo Bum's Avatar
 
Join Date: Feb 2008
Quote:
Originally Posted by R45VT
Next time say there is an adjustment but it won't do shit.

I thought I remembered you posting that last time.

Just might be a little misleading for someone.

And thank for posting the mA values. Goes to show how cold they are.


Yeah that's the bottom line. I'm just going to save that post and have it ready to post whenever someone asks this.

I'm also possibly thinking of doing a bias mod tutorial if I have the time.
Tremolo Bum is offline   Reply With Quote
Old 09-16-2012, 09:06 PM   #12
Kevin Saale
Talks to empty chairs
 
Kevin Saale's Avatar
 
Join Date: Dec 2007
Location: In a desert, next to a chair
Just put new tubes in and crank the bias adjustment. Note, I only recommend that for this amp because they're biased super cold and the adjustment does like nothing.
__________________
I don't give a shit if you listen to me or not.

Quote:
Get three coffins ready.

My mistake, four coffins.
Kevin Saale is offline   Reply With Quote
Old 09-16-2012, 09:09 PM   #13
R45VT
Doesn't speak guitar
 
Join Date: Dec 2009
Location: Traffic Town LA
:
Quote:
Originally Posted by Tremolo Bum
Yeah that's the bottom line. I'm just going to save that post and have it ready to post whenever someone asks this.

I'm also possibly thinking of doing a bias mod tutorial if I have the time.


It would be helpful. This question is asked often.

Last edited by R45VT : 09-16-2012 at 09:10 PM.
R45VT is offline   Reply With Quote
Old 09-16-2012, 11:13 PM   #14
ikey_
Registered User
 
Join Date: Dec 2009
Location: Raleigh, NC
are you talking all tubes or just power tubes? if your doing all of em, chances are some of your preamp tubes might still be fine, and doing a mix might give you the tone you want. ie - replace 1 or 2 at a time or something and see what affect it has rather than doing all 6 at once. you might not ever figure out what tube position makes any difference.

but yeah v1 is king.

also, a 6505 has a tone of tubes, so doing al lof em would be costly. you might just find doing a few here and there takes care of it for less
__________________
Carvin CT624
Walden G630ce Acoustic
Carvin V3M, Avatar 2x12 WGS Reaper, vet 30
(crybaby, Fairfield circuitry Comp, GFS tuner, Vick Audio 73 Ram's Head, Xotic AC booster, lovepedal trem, TC Flashback, PGS Trinity Reverb, Walrus Audio Aetos power)
ikey_ is offline   Reply With Quote
Reply


Thread Tools Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump



All times are GMT -4. The time now is 09:35 AM.

Forum Archives / About / Terms of Use / Advertise / Contact / Ultimate-Guitar.Com © 2014
Powered by: vBulletin Version 3.0.9
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.