"All Tube" - Not Always True

[hipofutura]

I've noticed many members and manufacturers referring to amps as "all tube". This is a bit of a misnomer as most of these "all tube" amps are not, as they use solid state rectification. There aren't a whole lot of amps being made that still use tube rectifiers. I fell this distinction is important as the tube rectifier is responsible for the sag that is the distinctive tone from the 60's - 70's amplifiers.

Deciding a few months ago to pick up the guitar after a thirty year break, I began researching what amp to buy. It wasn't until I looked really close at the amp specification (sometimes the schematics) that I realized even many of the "all tube" Fenders used solid state rectifiers. I was quite surprised as tube rectifiers were a huge part of the old Fender sound. It was for this reason I went with a custom shop amp based on Fender BF topology.

 

[Classicplayer]

Would it not be a good idea for someone to post the names of those amps that actually have the tube rectifier, or at least offers a choice. I think Fender's
recent Bassmans still offer that choice. Am I wrong?

Based on what you say, are amps advertised as all tube models, just really
another form of "hybrid" amps?

Classicplayer

 

[General Disarray]

My Dual Rectifier has the option of tube or diode rectification (hence the name)

 

[siore]

True. I kinda cringe at that myself. But I'd rather have a solid-state rectifier, and real pre-amp and output tubes, than something marketed as a tube amp but is really a hybrid. Now, isn't that facepalm-worthy!

Anyhow, a lot of amps have a ss rectifier. All tube may not be correct and proper, but a lot of those are darn good tube amps! It's really up to the guitar player, and his preferences. If you want the sag of the 60s-70s fender sounds, then go have the one with the tube rectifier.

Schematics are easily obtainable nowadays, so it's quite easy to determine which ones have tube rectifiers.

Here's one site for tons of fender info and schems:
The Fender Amp Field Guide

 

[drewbertca]

It's true that most amps today use solid state rectifiers but they still have an all tube signal path. The signal never passes through the rectifier. The rectifier converts AC voltages to the DC voltages that tubes use. It's true that they do affect sound due to the fact that they are less efficient than the solid state counterparts.....

 

[dwagar]

Marshall changed to SS rectifier with the Plexi (from what I've read), so a lot of that tone from the 60s and 70s weren't tube rectified.

 

[djlogan33]

I've noticed many members and manufacturers referring to amps as "all tube". This is a bit of a misnomer as most of these "all tube" amps are not, as they use solid state rectification. There aren't a whole lot of amps being made that still use tube rectifiers. I fell this distinction is important as the tube rectifier is responsible for the sag that is the distinctive tone from the 60's - 70's amplifiers.
=====================================================

I’ve only been playing guitar and using amps for a couple of years.

Please explain to me why “tube” amps are considered better than the new/modern digital amps.

Being an “IT-guy” by profession, I am always looking and listening to the latest advances in computers and digital technology.

I have observed that the newer and better digital amps are “modeling” or duplicating the tube-amp tones pretty darn close.

I have been playing around with two very nice tube amps (Fender Vibro-King & ’65 Super Reverb) in my basement studio.
They sound very nice, but my new Line 6 digital amp can produce tones very close to the tube amps and with the two 10” speakers, pretty loud too.

Below is what I wrote in a LINE-6 post.

==========================================================
I recently purchased a LINE 6 Spider III 120 watt with 2-10" speakers.
I have had no problems with it.

A friend of mine that rents musical equipment to bands has been letting me use two nice Fender tube amps:
• Fender Vibro-King with 3-10” speakers
• Fender ’65 Super Reverb with 4-10” speakers

I really like using these amp but they are so big and heavy 65-72-pounds and very expensive.

I attend Blues Jams and really hated plugging into some unknown tube amp not knowing how to set it up quickly.

I wanted to bring my own amp to the Jams that was fairly light-weight that sounded good enough and would be loud enough to stand up to the other larger tube amps on the stage.

I really like my LINE 6 Spider III 120 for the following reasons:
• Multiple presets
• Multiple Amp models (Clean, Twang. Blues, Crunch, Metal, Insane)
• Multiple effects
• 2-10” speakers
• Loud enough to be heard with larger tube amps
• Light weight 47-pounds
• built-in tuner
• inexpensive ($359 @ Guitar Center)

 

[Angus]

I've noticed many members and manufacturers referring to amps as "all tube". This is a bit of a misnomer as most of these "all tube" amps are not, as they use solid state rectification. There aren't a whole lot of amps being made that still use tube rectifiers. I fell this distinction is important as the tube rectifier is responsible for the sag that is the distinctive tone from the 60's - 70's amplifiers.

I was told recently by a very good amp engineer that my early seventies AC30 used a solid state rectifier, but not to feel bad as most of the old Marshalls from the late sixties and seventies did as well.

Its possible I misunderstood, but I'm pretty sure that's what he said.

 

[Classicplayer]

I'll take a stab at the answer as to why tube amps are considered "better".
Please don't get me wrong, as I like the SS and digital models too. I've owned those two types and also tube amps.

Tube amp sound has become the preferred type due to the fact that the old
amps from the 50's and 60's that early Rock (& Roll) guitarists used produced that big fat and sometimes distorted sounds that many R & B and Blues players used. It was a very appealing sound. When that type of sound was explanded on by Clapton, Page, et. al. it became even more accepted. Guitar players sought amps, usually tube models, because that was the only way to get that popular tone. Solid State could only imitate it. Today SS gets close and modeling amps get close, but tube amps still pretty much rule. Especially in the world of Rock music.

To electronic engineers, tube produced sound probably seems silly, but to guitar players who want like that sound of tubes as well as the "feel" of a tube driven amp, it continues to make sense....not silly at all.

Classicplayer

 

[zplapplap]

The original Bassman reissues from the early 90's had solid state rectifiers. The designers said that they couldn't keep the amps from blowing it out (same old problem ). They were able to replicate the response and tonal characteristics to my satisfaction. My brother owned one of the early reissues and it met his high expectations.

My Super Reverb Reissue has a tube rectifier, tube tremolo, and tube reverb. Would this qualify as all tube? I can't imagine why not. I guess I don't really care. But this vintage series model seems to be an option for those that aren't ready to make the jump in price to the custom hand-wired stuff. How important is this all tube thing, especially if there are other ways to emulate the power sag. I would concievably opt for a pine cabinet if I could choose between that and the tube rectifier.

 

[Jason]

Djlogan, Some people refuse to settle for "pretty darn close". For me, it either sounds real or it doesn't and if it doesn't I just can't get over it. A guitar plugged straight into hot tubes is one of my favorite sounds in the world. Sometimes I even get pissed at the way a single pedal can ever so slightly squish my tone... There are always compromises to be made, but I want as much of that sexy tone as I can get.

 

[siore]

I like some solid state amps too. Some will sound close. But in terms of what you can do to a tube amp, like varying your picking attack or rolling your guitar controls, or putting a stompbox in front of it to push it for more gain, or just plain cranking it to get the fullest harmonically richest thing you've ever heard, most of the modellers fall short. And it's about some of the most fun a guitar player can get, that 1-on-1 interaction with a tube amp. It's not just the sound dude.

It's a whole non-linear and dynamic thing that happens in the vacuum within those glass thingies. To be able to nail it spot on with processors, you have to anticipate every sound, every variation of frequency response, things like sag or natural compression. Listen closely to the response you get on your modellers, it will have some abruptness, some jagged minute changes, not very smooth as compared to amps with tubes. Not to mention tube amps are very inconsistent! One amp may have an endearing trait to it, at the expense of another trait, just as desirable in another amp of the same make. Now, how do you know a model will model exactly the amp you want?

I do embrace technology, and I believe someday it will approximate the warmth tube amps give us. But nailing it exactly is like trying to anticipate the way a building responds to an earthquake. A structural engineer can tell you, "yeah we have the technology to predict it", but ask him if he's covered all bases... most likely you'll get, "we've only truncated up to this mode, we have a factor of safety of so and so, we've based our computations on this graph, based on the study of this guy, so on and so forth." Technology still has its limitations.

Again, it's a nonlinear and dynamic thing. It changes and it's not as predictable as just sound.

But your audience may not know. After all, it's an interaction with the guitar player and his other gear that endears him to the tube amps, but the audience may not care any more than the sound coming out of the speakers. That is why there is always a place for solid-state, or digital amps. I don't mind playing through one. But for what I consider really fun, it's all about the tubes.

I'm sorry I got carried away with a lengthy post. But tube amps are still king for me. But I do like the versatility and convenience the other amps give us.

 

[randygt]

Recording in a studio is a little different beast than playing live. I've heard some studio tracks layed down with a pod that were very nice. I'm not talking saturated distorted big delay stuff either. They do have their niche

 

[djlogan33]

I'll take a stab at the answer as to why tube amps are considered "better".
Please don't get me wrong, as I like the SS and digital models too. I've owned those two types and also tube amps.

=========================================================
Thank you for the explanation.
I've heard similar explanations before.

But being over analytical about most things, I would like to see a graphical representation of a digital vs. tube amp.

It would be interesting to use a sound-meter to graph of a series of notes (from a guitar) on a tube amp and a digital amp (both having the same size speakers) to see if the sustain/tone/vibration differences.
...and at the same time observe if you could hear or feel the difference.

Just a thought.

 

[Deus Vult]

tube distortion sounds more complex....its hard to explain on a forum. i used to run an OD pedal into the clean channel on my HRD. now i use the TT and no pedals to get a similar sound. to my ears, the TT just has some overtones to it that the pedal distortion doesnt provide. tube distorion all responds much better to your pots, your pick attack, etc.

 

[siore]

I'll take a stab at the answer as to why tube amps are considered "better".
Please don't get me wrong, as I like the SS and digital models too. I've owned those two types and also tube amps.

=========================================================
Thank you for the explanation.
I've heard similar explanations before.

But being over analytical about most things, I would like to see a graphical representation of a digital vs. tube amp.

It would be interesting to use a sound-meter to graph of a series of notes (from a guitar) on a tube amp and a digital amp (both having the same size speakers) to see if the sustain/tone/vibration differences.
...and at the same time observe if you could hear or feel the difference.

Just a thought.

Yes, it probably would be. But I say, let their experts and engineers come up with something, then let's try playing through it (or let me play through it while you look at the graphs ). But to this point, I hear and feel the difference.

Very close may be good, as one says, they do have their niche. Especially for the touring musician, all practicalities considered. If you don't feel the need for tubes, then sell your tube amps, don't worry about what others may have to say about your modeller.

As they say, whatever floats your boat.

 

[hipofutura]

DJ, The 'sag' that tube rectifiers add to the amps tone is cause by the rectifier not being able to pass the power to the tubes fast enough. This results in the amps audio output being slurred (or sagged) and the input signal from the guitar is not faithfully reproduced. SS rectifiers don't color the sound because they are able to react fast enough. This is most noticeable in tube rectified stereo amplifiers. Old tube stereo amps with tube rectification sound terrible. When the music surges and places a high draw on the amps power supply the out drops off and sounds awful. This is why high-end audio tube amps use SS rectifiers. Unlike guitar amps, with stereo gear you want a faithful reproduction of the input signal. If you want a high powered guitar amp that can accurately reproduce the signal from the guitar, then you would want SS rectification. However, many guitar players, myself included, like the warm, funky, bluesy, soulful (call it what you will) sound of of a true "all tube" amp.

 

[Shawn Fate]

I prefer the SS when using Dual recs.
As long as the amp sounds good i dont care what it is.

 

[randygt]

+1 what shawn said. Personally, If I was playing metal I would want a ss rectifier for the attack it brings to the table.

 

[djlogan33]

tube distortion sounds more complex....its hard to explain on a forum.
===================================================

I’m still fairly new to the complexity of guitar amplifiers, so I find it very interesting and informative to read all the comments.
I’ve only been playing electric guitar for around four years, so my ears are not good enough to hear what you guys have learned over many years.

I do have the luxury to be using my buddy’s Fender Vibro-King & vintage ’65 Super Reverb to play with and experiment

I find it fun and a challenge to try to make my new LINE 6 Spider III 120 sound as close as possible to the large tube amps.
When I do find a certain tone I like, it is nice to be able save it as one of the many pre-sets available.

I do have a couple of questions about how to get the best-fat-blues tone from the Fender Vibro-King amp.
I know much of it is personal preference but I would appreciate your opinions.

How should I set each of the controls?
• TREBLE
• BASS
• MID
• SPEED
• INTENSITY
• DWELL
• MIX
• TONE

Also, should the Les Paul tone knobs be wide open or backed off a little?
I tend to play the LP most of the time using both pickups.
Sometimes just the neck pickup, but seldom use just the bridge pickup.
What pickups should be used and when?

Thanks.