What is SAG?

Re: What is SAG?

Thanks alot Rich_S for your information

1.) Why does picking dynamics *draw more current* from the power supply?
(What makes it draw more current?)


2.) How can u make your preamp have alot of SAG?
( SAG the power rails?)

3.) What tube recifiers have SAG built in them?
(is it the internal resistance?)
 
Re: What is SAG?

Sag is caused when I put my foot up a troll's ass so far I lose my shoe. It's so heavy, being a size 14, that the muscles and skin start to elongate causing a visible difference in the appearance of the troll's ass. This is commonly known and referred to as sag.

That's a thing of beauty right thar. :bigok:
:butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick: :butkick:

Does it look something like the above, but with vigorous butt-sagging action going on for the troll?
 
Re: What is SAG?

Thanks alot Rich_S for your information

1.) Why does picking dynamics *draw more current* from the power supply?
(What makes it draw more current?)


2.) How can u make your preamp have alot of SAG?
( SAG the power rails?)

3.) What tube recifiers have SAG built in them?
(is it the internal resistance?)

1) Picking hard makes it louder, draws more current.

2) You can "soften" a preamp by messing with its bias - reducing or eliminating the bypass cap on the bias resistor. It's not really sag, but it has a similar effect of reducing gain as you play harder.

3) I'd have to dig out my tube manuals to say for sure, I don't remember off the top of my head.
 
Re: What is SAG?

Picking hard makes it louder, draws more current.

1.) What is drawing the current from the power supply?
2.) is the preamp or power amp drawing the current?
3.) What else can make the power supply draw more current?
 
Re: What is SAG?

Most of the current draw from the power supply goes to the output stage. Sag is the PS' inability (in a linear, hi-fi sense) to keep up with the demands of loud passages. Unless you're running an amp near its limits, it sag will not be part of the tone.

What sort of amp do you have/are we discussing?
 
Re: What is SAG?

hard picking is overloading the amps input which draws more current?

The amps preamp has "less gain" would it have more SAG?

I still am confussed about HOW picking dynamics draws more current from the power supply i can't picture this in my mind as to how it does this. All i can think is that the preamps gain draws more current its SAG is based on GAIN and gain draws more current from the power supply??

Block diagram or steps and how its draws current from the power supply please

1.) louder picking dynamics
2.) Preamp is overloaded
3.) preamp draws more current from the power supply?
4.) power tubes section draws more current from the power supply?

is this how it works ?
 
Re: What is SAG?

Most of the current draw from the power supply goes to the output stage. Sag is the PS' inability (in a linear, hi-fi sense) to keep up with the demands of loud passages. Unless you're running an amp near its limits, it sag will not be part of the tone.

What sort of amp do you have/are we discussing?

Rich, you're wasting your time. At least the info you've posted may help others. However, you will end up like this: :banghead:
 
Re: What is SAG?

Someone should recommend Walters a book, before Rich writes one on here for him! (If he does, it is of course vault-worthy.)

I agree with JP that Jack White's tone is a great example of sag. Check out "Ball and Biscuit" from the album Elephant. There, you can here the difference that comes from a change in volume and picking dynamics. He probably kicks in a pedal as well for extra oompf.

- Keith
 
Re: What is SAG?

Sag is a characteristic of an overloaded OUTPUT stage. Forget overdriven preamps. In fact, high-gain preamps reduce picking dynamics, and get in the way.

For sag to factor into the tone equation, the preamp must be able to pass the guitar signal in a fairly unadultered state, with all of its dynamic range intact. When you hit a loud chord, the output stage is driven beyond the amp's ability to provide power to the speaker. What this means is, the output stage pulss current out of the back end of the power supply faster than the front end can replace it. This momentary over-draw causes the B+ voltage to SAG. As the chord passes out of it's initial loud "attack" into the "sustain" and "release" sections, the B+ has a chance to recover back to its normal state.

This is the same thing that happens to the cold water pressure (B+) when you flush the toilet (large current demand), although there's no analog in the amp for the a$$-scalding the person in the shower gets.
 
Re: What is SAG?

Sag is a characteristic of an overloaded OUTPUT stage. Forget overdriven preamps. In fact, high-gain preamps reduce picking dynamics, and get in the way.

For sag to factor into the tone equation, the preamp must be able to pass the guitar signal in a fairly unadultered state, with all of its dynamic range intact. When you hit a loud chord, the output stage is driven beyond the amp's ability to provide power to the speaker. What this means is, the output stage pulss current out of the back end of the power supply faster than the front end can replace it. This momentary over-draw causes the B+ voltage to SAG. As the chord passes out of it's initial loud "attack" into the "sustain" and "release" sections, the B+ has a chance to recover back to its normal state.

This is the same thing that happens to the cold water pressure (B+) when you flush the toilet (large current demand), although there's no analog in the amp for the a$$-scalding the person in the shower gets.

+1.

One of the best solid state amps for sag is the old Kustom K200B. It uses a heavily regulated +/-8 volt supply for the preamp sections which allows it to keep all of the signal dynamics. The poweramp section, as with most solid state amps is unregulated.

When you crank it up enough, especially feeding it's minimum load of 4 ohms, it has some of the best sag you will ever encounter.

And not only can you hear it, you can SEE it - the pilot lamp is connected between the poweramp positive supply and ground. When the voltage drops due to sag, the pilot lamp dims right along with it.
 
Re: What is SAG?

Thanks alot guys for the information and time

What amps solid state or tube amp have alot of SAG?

since the twin reverb is the wrong amp which amps have the SAG built in ?
 
Re: What is SAG?

Thanks alot guys for the information and time

What amps solid state or tube amp have alot of SAG?

since the twin reverb is the wrong amp which amps have the SAG built in ?

It's not that SAG is built in, but it is the result of their construction.

Any tube amp that has a tube rectifier will exhibit some degree of SAG. How much depends on the power transformer's ability to provide current when it is needed - the lack of ability will result in more SAG.

That pertains to solid state amps as well. And contrary to one of your previous posts, most solid state amps do not have regulated power supplies. The Kustom example is the only one I can think of off hand that has any regulation in the power supply circuits at all.
 
Re: What is SAG?

buy gerald webers books

Whaddayou?!?!?!?!?!? Some kinda Gerald Weber PITCHMAN!!! :laughing: :laughing:

Don't try to deny it! You probably speak with a thick Texas Drawl just like that horribly unprofessional Gerald Weber does in his videos. :23: :23: :23:

:9:
 
Re: What is SAG?

never seen the videos and yes he's my uncle so there!

not really. i think walters should go read those books or at least dave hunters tube amp book and he will learn much of what he is asking. there are so many things that interact to get a certain sound that i think he would benefit from some time spent practicing his reading skills
 
Re: What is SAG?

I have all the videos on one DVD. Pretty informative, but I'll bet it leaves out a lot of the formulaic stuff that's necessary to tube amp repair etc. Gonna have to get the books anyway now...
 
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