Tube Amp Myths

wulfenganck

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"You just don't get dynamic response and warm tone out of a solidstate amp!"
B.B. King: "Hold my beer!"

"Only tube amps provide a harmonic distortion sound!"
Same guitarplayer:
"I get my distortion mainly out of pedals!"

"Tube amps with mastervolume don't provide smooth overdrive, you need poweramp-saturation for the right overdrive!"

"If there is a single transistor in the signalchain, it's not a real tubeamp - you'll hear the difference!"
 

Paul G.

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You need to bias your amp with every power tube change.

Back in the day, the repairman simply pulled the bad tube and stuck a new tube in its place. No biasing.

"Back in the day", tubes were manufactured with much tighter tolerances. You could just swap power tubes and probably be right where the bias should be. You could go to the corner drug store, test your tube, and buy a tube right out of the cabinet the tube tester sat on. You could swap out one power tube and be pretty sure everything was ok. As long as the bias among tubes isn't so off as to cause hum, you're fine.

Now, I will admit nowadays there is "bias obsession", as if you need to be at NASA or Neurosurgical precision on the bias, this is malarky. There is a good range where your amp will do just fine. The guys who sit in quiet rooms carefully listening while adjusting bias for the magic spot are kidding themselves. Guys who carefully dial in exactly 70% MPD because they read that it was the "best" are wasting time. Wall voltages and temperatures vary. Tubes wear. The point is, there is no point. Usually anywhere between 55% and 65% is fine. If things work, well...
 

Cosmic Cowboy

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Feathers have not been ruffled...gotta step it up a notch...

Tube swaps will not 'transform' your amp.



Interesting feather ruffeling topic. I have enough real world experience to know that there are tubes I like, and others I pulled after a day or two and reside in boxes. I have 6L6's 6V6s, EL 84s, 12AX7s, AT7s by the dozens.

The flip side, the particular tube makes little difference compared to things like the circuit, speaker, and pickups.
 

DrBGood

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Maybe should have started this thread with the definition of a myth.

Myths are sometimes distinguished from legends in that myths deal with gods, usually have no historical basis, and are set in a world of the remote past, very different from that of the present. Maybe should have used popular belief instead.

Popular belief would be more accurate or internet tales. Because before internet, tube amps didn't need any special knowledge to be used properly. Plug in wall socket, flip switch, plug in instrument and play.
 

Paul G.

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I have read that leaving the standby switch engaged and turning off the power switch may help drain the caps, does anyone know if this is true?

Yup, especially if you do the hit a chord while it fizzes away. With the standby in the on position, your hot tubes will continue to conduct until all the power stored in the reservoir and filter caps is gone. That's your fizzle out. They'll still discharge if you don't play with the power off and standby on, but it takes longer for the caps to discharge.
 

sax4blues

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I find most gear discussion very much like wine discussion. The major varietals are distinct; Telecaster-Les Paul, or Princeton-JCM800.

But then we get to which side of the road the grapevine is on, French or American oak barrels, hints of this, notes of that, cork stopper vs screw on cap, yadda yadda yadda. Everyone tastes, hears, and feels something a little different. But most often it’s what they are told to taste, hear, feel.
 

JustABluesGuy

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I find most gear discussion very much like wine discussion. The major varietals are distinct; Telecaster-Les Paul, or Princeton-JCM800.

But then we get to which side of the road the grapevine is on, French or American oak barrels, hints of this, notes of that, cork stopper vs screw on cap, yadda yadda yadda. Everyone tastes, hears, and feels something a little different. But most often it’s what they are told to taste, hear, feel.

It helps to know that we humans are prone to this. I know for sure that it has happened to me.

I had long heard that a certain pedal was terrible and fizzy sounding, and that was my experience as well.

Then I saw a few videos from people who liked the exact same pedal (and also used it more appropriately IMO). It sounded great to me when used that way, and I still use that pedal to this day.

Part of the improvement was in the different way the pedal was used, but part of the difference was definitely psychological.

I was influenced by the widely held, general consensus that I was “supposed” to dislike the pedal, like most folks do.

It wasn’t pleasant to realize (and admit to myself) that I had been involved in (or was even susceptible to) such “groupthink” but I was. It’s was better to realize it, and get out of the groupthink than to maintain my “psychological and social comfort” by simply continuing in it.
 
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Tuneup

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Tubes should be hard to pull out if your fingers are soaked in chicken or motorcycle grease. If they come out easily the sockets need tightening. Clean the grease off the tubes afterwards unless you like your studio to smell like Church's or Hank's Happy Honda House.

Other parts warm up besides the tubes. Resistors drift, some caps too, heck the whole frigging thing including the speaker gets warm including the player and hopefully whoever's listening. Neighbors might get hot under the collar.
Is your avatar a Crumb comic?
 

Digital Larry

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Clean the grease off the tubes afterwards unless you like your studio to smell like Church's or Hank's Happy Honda House.
OK, but I use a modeler and I want that smell in the studio. What to do?

Carlos Santana's amp (made by Bob Gallien) at Woodstock
Having worked at G-K for a few years back in the early 90's, I got to know Bob a bit. I see him at Home Depot every few years. Of course I heard this story. There's a recent interview with him by Mitch Gallagher on the Sweetwater web site. I don't know how to link directly to it. The story of that amp is pretty incredible. I find Bob refreshingly straightforward and humble given the impact of his designs on the bass world.

I wonder if ‘myth ridiculousness’ can be plotted and if so, is the growth exponential?
Graphs! I need graphs!

Some of the last of my old junk.
Awww. You need more!

went to the proctologist
I'm missing a few 6L6s and a matched pair of EL34's. Hey... I slipped in the shower!
 
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kLyon

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"You just don't get dynamic response and warm tone out of a solidstate amp!"
B.B. King: "Hold my beer!"

"Only tube amps provide a harmonic distortion sound!"
Same guitarplayer:
"I get my distortion mainly out of pedals!"

"Tube amps with mastervolume don't provide smooth overdrive, you need poweramp-saturation for the right overdrive!"

"If there is a single transistor in the signalchain, it's not a real tubeamp - you'll hear the difference!"
Albert King too... I saw him live at Tipitina's way back in the day and couldn't believe the sound he was getting out of those Acoustic stacks... with horns! like an old church pa system))
 

schmee

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Top of the season to all of ya's! Let's take on all the misapprehensions out there. Keep it simple, or explain away!

First up, tubes do not need a warm-up period to sound 'better'. They don't 'breathe' more once warm, nor can they create 'space'.

How long do they need? A minute? Until they work?

A tube amp that needs twenty minutes to warm up also needs service.
They sound good right away.
They may sound better after 5 mins or so.
The bias setting changes slowly, maybe as a much as 5 milliamps over 5 minutes.
They may sound better or worse after an hour with everything hot.
 




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