what is sag?

[Red Ryder]

It’s the thing that clothes hide in Cheap Tequila.

Damn you Powdog, you beat me to it. A fantastic tune which I always get good audience response. Fast or slow, blues or rock or country style, it tells the story.


P.S. Can't explain the other I just like what my amp does.

 

[Trenchant63]

I steer clear of amp sag because I like immediacy and punch equal to the pressure I put on the strings from my amp. If I want a softer attack, I’ll adjust picking angle. When I had an amp that sagged with a tube rec, I did not like it. Others really like this but I’ve never been into it.

 

[Neptical]

Ever play a Rectifier? That's THEE Sag.
Now, play that sag with a clean boost and it becomes AMAZING.

 

[gimmeatele]

Funny you should mention this, I was trying to find out what sag, ripple and hum did on the pod go amp settings yesterday, not alot was the conclusion

 

[telemnemonics]

Note that amps can have sag without having a tube rectifier, it can be caused by any inadequate or weak link including filter caps, underrayed PT, saturated OT, and even the preamp recipe.
Most amps known for sag have a combo of several of those things.

Whether we "like sag" or not I bet few players would like a guitar amp with no envelope at all, some amount of "feel" or envelope is built into almost all guitar amps and makes them easier to play.

 

[Trenchant63]

Note that amps can have sag without having a tube rectifier, it can be caused by any inadequate or weak link including filter caps, underrayed PT, saturated OT, and even the preamp recipe.
Most amps known for sag have a combo of several of those things.

Whether we "like sag" or not I bet few players would like a guitar amp with no envelope at all, some amount of "feel" or envelope is built into almost all guitar amps and makes them easier to play.

Good point on all amps having a bit of sag. Even just the signal going from your guitar to the movement of the speaker is “sag”. Probably the only amp without sag is your eardrums hearing the guitar unplugged.

 

[telemnemonics]

Good point on all amps having a bit of sag. Even just the signal going from your guitar to the movement of the speaker is “sag”. Probably the only amp without sag is your eardrums hearing the guitar unplugged.

Well that was not what I meant, not all amps, all "guitar amps in general".

Plug straight into say a big PA rig with a graphic and set a guitar friendly EQ, the amp still lacks feel and we may hear it as harsh or say it is hard to play. Because if it is a good rig, the transiants are full speed with no sag, no limiter, no compression at all.

Some guitar amps lean this way too, like the late '70 UL Fenders, the worst I found being the Bassman 135.
I had a 70w Pro, a 135w Twin, and the Bassman 135.
Some complain they are bright or maybe strident, but the EQ is adjustable. What you cannot adjust out is the hard fast attack with no feel, and at the other end of the note, no compression.
A 1969/70 100w Marshall turrned down is similarly very fast and tricky or uncomfortable to play, just brutally fast and hard harsh, until turned way up. Not impossible but an example of a very fast guitar amp.
Hiwatt 100 not so much in my experience, but still very much a sag free amp.

I had a Quilter Superblock for a while and the transients were harsh, like if you hit the strings just a little too hard the sound spiked in a nasty manner. The limiter helped that, I guess the class D power amp has zero feel or envelope or sag and compression.

It is actually harder and more expensive to build a tube amp with no sag at all, where every part of the power section can be less, just right, or more; than the overall output requires.
Filter caps can be less than needed and you get a nice feel with no tube rectifier, but you get some current ripple and ghost notes.
The OT can be a bit small and saturate which causes sag with no tube rectifier, but the bass crowds the bottleneck worse so your bass distorts more than your treble.
Power transformers may provide barely enough current and create sag, which is actually a nice response but the PT overheats.

 

[naneek]

huge thanks to everyone who replied. With all the aspects of this that different people brought up, I have a really good understanding of this now.

This explains why the pick attack on my 80 watt solid state Tel Ray supernova can sound like an atomic bomb going off, and my tube amps don't seem to emphasize that punch as much. I've always said that amp sounds like a club sound system, so this makes perfect sense:

Plug straight into say a big PA rig with a graphic and set a guitar friendly EQ, the amp still lacks feel and we may hear it as harsh or say it is hard to play.

Sometimes I like that about it but it's true I have to be way more careful with the dynamics in my playing.

Some really famous all-tube amps have minimal sag - a Twin Reverb for instance, or a Hiwatt. Those amps are great at producing lower register notes that don't sound "spongy" and they tend to feel like they are capable of "more" volume. For a clean amp sound I like minimal sag.

This explains my mid 60's Gretsch Dual Twin, which is really tight and incredibly loud for only 18 watts. It was designed so that 2 guitars, a bass, and a singer could plug into it and play at performance volume with no distortion. It has that crystaline clean tube sound, with no distortion, just pure clean headroom. Makes sense that this amp was designed to have minimal sag.

It also explains what Dick Dale said about the Twin Reverb- he said it was the only amp that gave him "the volume and the click of the pick." Because it was loud and powerful, but the response was quick enough to have a clear and defined pick attack with his superfast picking.

It refers to the amp being slow to recover. Meaning how long it takes the power supply and rectifier to interact.

And this explains why we have triple rectifiers for the metal heads haha. I never understood the point of a triple rec until now.

 

[RoscoeElegante]

Hey, the OP asked for it!

No one will believe this isn't me, so send me that oil truck of sunscreen and be done with it.

I actually really like sag (and bloom) as an amp's feature or characteristic. I'm glad that it's sometimes deliberately put into amps, as in Fender's Excelsior's two sag resistors (R22 & R30). I find myself turning up reverb or adding delay pedals to sag-less or -minimum amps. But I can also see how if you're really rocking, you want sag-free immediacy, especially for power chords, etc. (I've also seen amp gurus say that sag can cause or increase honkiness and nasality...?)

 

[11 Gauge]

Good point on all amps having a bit of sag. Even just the signal going from your guitar to the movement of the speaker is “sag”. Probably the only amp without sag is your eardrums hearing the guitar unplugged.

Single-ended amps have zero sag, due to their design, and their class A operation.

From this page:

Is your amp a single ended amp? If the answer is yes, then sag is not a factor. A single ended amp is a class A amp; this type of amp is drawing maximum current while at idle. Initially, when you strike a note, the voltage and current both drop and the load on the power supply is reduced. In a single ended amplifier there can be no sag; it is not possible. It makes no difference if you have a tube or a solid state rectifier; it is impossible to produce sag. A single ended amp will typically have one power tube—a 6V6, 6L6, or maybe an EL84—and produces 5 to 12 watts.

Based on the above, I love when some piece of gear has a control, knob, or switch labeled sag, and it has nothing to do with a push/pull power amp. While you're hearing some sort of effect, it simply is not sag by the actual definition.

IMO, the link above does a decent job of explaining just what sag is, and what actually causes it.

 

[Tele_Tom64]

It's usually associated with tube amps and is what the folks above said. Along with presence and resonance, a common amp term. H&K gets it. I wish all ss amps had their controls.

Ive noticed that there are Sag controls in Fender Fuse for many of the "amps" available on the previous generation of Fender Mustang amps. Most days, I use my tube amp but I still mess with the Mustang every now & then, in an attempt to get a decent sound out of it.

It's a Mustang 2, 1x12 combo. Honestly, I'm just glad Fuse still works with it and they didn't do something stupid like cut off communication between the 2 in the last update.

 

[2L man]

Single-ended amps have zero sag, due to their design, and their class A operation.

From this page:

Is your amp a single ended amp? If the answer is yes, then sag is not a factor. A single ended amp is a class A amp; this type of amp is drawing maximum current while at idle. Initially, when you strike a note, the voltage and current both drop and the load on the power supply is reduced. In a single ended amplifier there can be no sag; it is not possible. It makes no difference if you have a tube or a solid state rectifier; it is impossible to produce sag. A single ended amp will typically have one power tube—a 6V6, 6L6, or maybe an EL84—and produces 5 to 12 watts.

Based on the above, I love when some piece of gear has a control, knob, or switch labeled sag, and it has nothing to do with a push/pull power amp. While you're hearing some sort of effect, it simply is not sag by the actual definition.

IMO, the link above does a decent job of explaining just what sag is, and what actually causes it.

That comment might be from HiFi builders forum?

When driven to distortion SE power amps can interact with tube rectified power supply which capacitors are small. Often increased Screen current has some effect to PS voltage fluctuation as well but Screen voltage interact to Anode current. Loadline is just a designing principle and when guitar amplifier power stage distort and interact with frequency dependant loudspeaker impedance and NFB is low or not used at all and when some OT core saturation is added the current and voltage can travel wildly all around the loadline

 

[JIMMY JAZZMAN]

It is a compressed sound (mostly chord playing) when hitting strings hard. Single note treble not as noticeable,
but hit them bass strings hard and you'll know it. Vox, Supro with a Les Paul, you can get "sag" with sustain
in spades.

 

[Festofish]

Ask yer mom.

 

[Lynxtrap]

The sound of sag:

 

[effzee]

Context is everything. Don't ask this in mixed company.

 

[johnny k]

screen actors guild

 

[eddiewagner]

In suspension sag keeps your wheel from falling into bumpholes too hard. If that makes sense to you.

 

[11 Gauge]

That comment might be from HiFi builders forum?

Actually, that website looks to mostly be for mics and pedals specifically for blues harp players.

And someone there is of the opinion that sag is generally not good for blues harp:

Disclaimer: this is my opinion and others may disagree. With that in mind, I do not believe sag is a desirable aspect of an amplifier for the harp player, and here is why. Harp players strive for a sharp articulate attack on their notes. Our instrument is inherently soft, producing more rounded notes, and to counter this we articulate our notes with syllables like “ta”, “ka”, “tukka” and so on. An amplifier with sag is counter-intuitive to this desire. A good harp amp needs to be punchy, to have drive to cut though a mix, and to be heard by the audience, and an amp with a solid state rectifier is conducive to this goal.

So I guess that one could argue that unless you play guitar in a way that's mostly 'soft/round' (legato, with no pick maybe?), then you possibly won't be a big fan of sag.

Anyway - back to the SE amp thing - I've got a '67 Champ with a 5Y3, and also a Blackheart Little Giant and VHT Special 6, with the latter two having SS recto. Despite the Champ having a tube recto and small filter caps, I can't audibly detect any sag from it, at all. The LG and Special 6 sound 'a lot bigger', but I attribute that to their massive OTs (LG has an aftermarket beast from Weber).

OTOH, I have a 5E3 clone, and it is a sag machine.