How to Bias a Tube Amp Part 1

This is a simple video on how to bias a tube amp

Category:

Music

Tags:

• Tube amp
• Bias
• Behind the tone
• Guitar amp
• tone

[behindthetone]

You can run the amp a little hotter but it won't change the tone that much & you will burn out tubes much faster. My suggestion is to put a nice overdrive in front of the amp. You can keep the gain on the overdrive low & just use it to drive the amp a little harded. This will bring the desired effect with out hurting the amp. Tube screamer is a all time favorite.

[TurdFurgusonABF]

I most def risk my life to save some money

[fuchurballs420]

what's the link to your website?

[Danhtran1122]

I think we use variable negative voltage source for grids bias of output tubes.

[keza123123123]

how many pins do 6l6 tubes have ??

[cityboating]

Why is this guy touching the tubes with his bare hands ?

Everything i have read says don't do this am I wrong or have i been given bad advice?

[yoheff988]

I'm using a Mesa Boogie Triaxis, lately the volume would drop in the middle of playing,

when I touched the output knob, it made a very loud crackling noise, naturally I thought

that the pot is bad and I cleaned it with some contact spray, someone told me that it can be one of the tubes, and not the pot,

any advice how to check that?

Thanks

[TalkToTheBody]

@behindthetone the only way to run the amp hotter is by increasing it's gain using the gain knob on the amp. Increasing it will obviously amplify your output to a point where natural distortion of the valves occur, giving that overdrive sound (whereas a solid-state amp just goes into saturation and you get nasty fuzz). The biasing of the valves is usually pre-set at a specific voltage (mV) and that's it. Not a good idea to lower or raise the bias voltage from it's nominal value

[TalkToTheBody]

@AssassinSteven I think a lot of what you heard is tongue in cheek stuff, you get no benefit running a valve hotter. A vacuum tube is designed to run at a pre-set bias and that's it. Crank up the gain/volume of the amp and the tube will deliver more amplification due to increased Cathode current hence the tube gets hotter the more you crank up the amp. I think this is what you heard.."i run my amp on max gain and full volume"

[chuckelator]

Hi, this video is great, but I wanted to know, if anyone can answer for me. I'm 26, and as of recently decided due to my insatiable appetite for guitar gear, a career in repairing, and possibly building/designing amplifiers makes sense to me, and would fit me perfectly. I have a aptitude for stuff like this, though this does seem a bit out of the realm of what I'm used to. Any recommendations on reading material or schooling that I could do???

[chuckelator]

@Filmpest And also, a cool trick to lower power if your interested in that, is if you have a amp with 4 power tubes, you can take either the outside 2 or inside tubes out and it will in theory half your power. Just make sure to drop your impedance selector down one step, IE. if you have a 16 ohm cabinet, run your amp at 8 instead. Learned that from a buddy of mine who used to build amps for Tone King.

[chuckelator]

@Filmpest Reason? In a class A/B amp, (which is the name for a push pull type amp) in a four tube amp, the outside two work together, and the inside two work together. If you pull out two side by side, it will screw up your impedance and will cause problems in your transformers. I'm learning about all this stuff myself, so I might not be exactly on, but that's the general idea behind it.

[Filmpest]

Sorry, I'm a beginner at this, but why the two inside and then the two outside, and not the two on the right and then the two on the left when testing?

[rwnfrd]

Give Information.Cheers Mate

[oatstao]

@AssassinSteven sounds like mythos

[satchrules101]

@behindthetone what tubes do u think satriani uses ??

[QAeternus]

@AssassinSteven He used a variac.

[AssassinSteven]

Eddie Van Halen didin't run his tubes hot... He ran his tubes on FIRE!!! Lol but no serisouly he ran them so hot that he actaully had to get a device ( forget whats its called ) to run more voltage into his amp to power them... I read in the Van Halen Saga that somtimes his tubes would melt and there was a period of time when he had to replace his tubes everyday because they would only last a couple of hours :p

[lukefenderrhodes]

@behindthetone are those ge 5150

[JustSomeRandomNewb]

@custardpiekashmir ok :d

[custardpiekashmir]

@JustSomeRandomNewb

was dus niet zo bedoeld :)

[JustSomeRandomNewb]

@custardpiekashmir Neen, maar de manier dat je zegt "volts don't kill, amperes do" heeft zo iets van das zever da da gevaarlijk is. Ik begrijp als je het hier niet me eens bent, maar het komt bij mij zo over.

[custardpiekashmir]

@JustSomeRandomNewb

tuurlijk is dit gevaarlijk, heb je mij dit zien ontkennen?

[JustSomeRandomNewb]

@custardpiekashmir neen, het is gewoon dat deze dingen zeer gevaarlijk zijn, en de ladingen die in de condensatoren worden opgeslagen dodelijk kunnen zijn, maar dat er dan mensen zijn die doen alsof het niets is en zo mensen die er niets van kennen niet de nodige veligheidsmaatregelen zullen nemen.

[custardpiekashmir]

@JustSomeRandomNewb

ligt het aan mij, of erger jij je nogal snel?

[JustSomeRandomNewb]

@custardpiekashmir but the volts will result in the high amps. Don't act smart if you don't know what you are talking about.

[bluesguitardude]

i have a 1986 carvin X60B head. new tubes are in the way, currently it has a set of 2 EL34"L" tubes from JJ. Im gonna install the same JJ's, sans the "L' (If im correct, the "L" is for low, meaning for massive bass... i hate those tubes...) will i have to bias the amp for the new tubes? will it affect my tone if I don't bias? according to what i read, this particular carvin head doesn't need a bias... but still, some info wouldnt kill me... any help could be aprecciated...