Virtual guitar amps/analog guitar amps

What is "sag"

Sag is the speed at which the note blooms, or how "fast" it is. A 6L6 amp has a lot of sag. The bloom happens fast. A 6L6 tube has a slower bloom, the attack is a bit slower. And how the amp is tweaked will impact sag. Certain amp makers specialize in bloom or sag.

Some serious players only like a slow bloom while others like a fast bloom.
 
Yup, I'm confused... :confused:

Don't be. I don't think the power tubes care one way or the other. I think, in my very general layman's understanding, a solid state rectifier will have a faster attack on the notes. You hit a note and it's there. A tube rectifier is "softer". That's "sag". The notes develop a little slower giving it a spongier, softer type of feel depending on the volume or power being pushed. It's kind of like the electrons in the tube have to sort of catch up to the note being played. That's how I understand it in my own warped way. Some players prefer more sag, some don't. Neither is better. It's just personal taste. I prefer a quick SS rectifier that gives you everything you ask for right away.

Of course I could have it all wrong. That's just how I've always thought about it. Like I said before, I'm not really good enough for it to matter either way.

I played some boutique amps recently that had switchable SS/tube rectifiers. I way preferred the SS rectifier setting.
 
MUCH depends upon the size of the smoothing caps fitted and whether or not a choke is used.

Thermionic rectified amps tend to have a choke. Sstate rectified amps rarely do. In any event, rectifiers only conduct for about 10% of a mains cycle to "top up" the caps.

I dislike valve rectifiers as a tech'. Costly, not just the valve but the specially wound transformer that is needed plus almost always a extra 5volt heater winding. Wasteful of power, both in the valve and the traff windings. Unreliable (and getting worse/more expensive).

And the "sag" effect can be duplicated by a simple resistor. "Purists" say it is not quite the same but I am not aware of any proper tests having been done?

Dave.
 
Sag is the speed at which the note blooms, or how "fast" it is. A 6L6 amp has a lot of sag. The bloom happens fast. A 6L6 tube has a slower bloom, the attack is a bit slower. And how the amp is tweaked will impact sag. Certain amp makers specialize in bloom or sag.

Some serious players only like a slow bloom while others like a fast bloom.

Thanks, interesting.
 
Sag is the speed at which the note blooms, or how "fast" it is. A 6L6 amp has a lot of sag. The bloom happens fast. A 6L6 tube has a slower bloom, the attack is a bit slower. And how the amp is tweaked will impact sag. Certain amp makers specialize in bloom or sag.

Some serious players only like a slow bloom while others like a fast bloom.

The power valve type is immaterial to sag. It is just a function of the rectifiers internal resistance and the power supply time constants i.e, C and L (if fitted).

Dave.
 
The power valve type is immaterial to sag. It is just a function of the rectifiers internal resistance and the power supply time constants i.e, C and L (if fitted).

Dave.

Yes and no. 6V6 amps typically by the nature of the chassy have less sag, not the tubes themselves, but the amps design. A 6V6 amp that has a slow response is going to be spongy and flubby. So, yes and no. That's why the old Fender Deluxes are so sought after, they have fantastic sag. They had to be fast due to their nature.
Maybe I have the misunderstanding.
I do know I do much prefer the SS rectifier.
+1 for SS rectifiers. That was a SRV mod on his amps. Except the Dumble SSS ofcourse..
 
Yes and no. 6V6 amps typically by the nature of the chassy have less sag, not the tubes themselves, but the amps design. A 6V6 amp that has a slow response is going to be spongy and flubby. So, yes and no. That's why the old Fender Deluxes are so sought after, they have fantastic sag.

Swap out the tube rectifier for a different type....and it all changes (assuming the amp's design can handle different tube rectifiers.
I love 6V6 amps and their growl.
I recently tried a few rectifiers in my Tungsten Creme Cortez 5E3 amp, which has some more modern modifications to the Fender 5E3 circuit, but is pretty much that flavor. I can run 5Y3, 5U4GB or 5AR4/GZ34 rectifiers in it....and the sag changes dramatically with each rectifier. I'm currently liking the 5U4GB in it.

I'm also using a 5U4GB in my KT66 Dr. Z Route 66...which originally called for a 5AR4/GZ34. The 5U4GB opened up the tone nicely. The 5AR4/GZ34 made the amp just too much in-your-face.

I've tired all my Weber Copper Cap SS rectifiers in place of the actual tubes, but I went back to the tube rectifiers.
That said, a couple of my amps have SS rectifiers by design, and they sound great with them too.

Just a lot of tonal flavors to pick from....no good/bad to any of it.
 
Yes and no. 6V6 amps typically by the nature of the chassy have less sag, not the tubes themselves, but the amps design. A 6V6 amp that has a slow response is going to be spongy and flubby. So, yes and no. That's why the old Fender Deluxes are so sought after, they have fantastic sag. They had to be fast due to their nature.
Maybe I have the misunderstanding.
I do know I do much prefer the SS rectifier.
+1 for SS rectifiers. That was a SRV mod on his amps. Except the Dumble SSS ofcourse..

Sounds like a circular argument to me!
6v6 amps are saggy because they historically used valve rectifiers so 6v6 amp are all saggy!

And in case anyone comes up with the hilarious idea that 6v6s are "slower" than the more modern EL34? They ain't and have been used as MF transmitters!

Dave.
 
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