Solid State and Tube Amp Observations

[whiskey02]

Just a thought based on my personal experiences. I'm talking about a pretty classic "straight ahead", clean, not overdriven/distorted tone. With a carved spruce top, SS amps just seem to go together/work better than tubes. With a solid body, tubes just give an organic life & depth to the sound that SS doesn't equal. I should say that I like to hear the sound of a guitar rather than the sound of an amplifier. I'd rather listen and identify a tele, LP or a 175, rather than is that a Polytone, Dumble, tweed if that makes sense. I mix and match all of the above with very pleasing results, but the apex of tone for me always ends up as I've stated. Sorry I don't have a laminate perspective.
Your thoughts?

[Bluedawg]

When it comes to archtops with floater pickups .... I've definately had better luck getting good tones out of solid state amps ..... my Fender DRRI is a pleasant exception to that

I'm still on the fence for top mounted pickups .... SS amps get great tones easily, but once you have dialed in the tone on a good tube amp it can be quite nice

[KirkP]

For amps designed for clean playing with lots of headroom, I suspect the main difference between the tone of SS and tube amps is the tone stack. SS amps typically don't use Fender-style tone stacks. If one used identical tone stacks, speakers, and cabinets, I think one could design high-headroom SS and tube amps that were indistinguishable at moderate volume levels. Of course SS and tube differ a lot when pushed into non-linearity, even slightly.

This can be a controversial topic! I'm not trolling -- just sharing my impressions, which are subject to change. :-)

[Spook410]

To me, a good tube amp sounds better than a good solid state in all applications. However, sometimes 'perfect' gets in the way of 'good enough'. SS amps are certainly good enough and have definite logistical advantages.

[jzucker]

i disagree with the original poster. To me , solid state amps are about convenience. A great tube amp operating within it's design efficiency parameters (i.e. not pushed past the limits of headroom internally or with its speaker) always sounds better to my ears. And the type of guitar doesn't really matter to me. A tube amp always sounds better.

However, there's a 3rd choice. A modeler such as the kemper which has the best of all worlds. Light and portable , extreme headroom but sounds like a tube amp.

[konstantine]

I usually use public transport to go to my gigs, as a rule I to bring with me only what I can carry so my Mambo 10 gets most of the action, its light, loud and sounds great. I prefer my tube amps but they are inconvenient.

[jorgemg1984]

For amps designed for clean playing with lots of headroom, I suspect the main difference between the tone of SS and tube amps is the tone stack. SS amps typically don't use Fender-style tone stacks. If one used identical tone stacks, speakers, and cabinets, I think one could design high-headroom SS and tube amps that were indistinguishable at moderate volume levels. Of course SS and tube differ a lot when pushed into non-linearity, even slightly.

This can be a controversial topic! I'm not trolling -- just sharing my impressions, which are subject to change. :-)

This is very true. The main difference between say a "jazz amp" and a fender tube amp is not technology but speakers, cabinet design, tone stack and type of reverb. I've tried a flat ss amp head (henriksen with a good reverb) with a fender eq pedal (barber barbeq) and a 2x12 open back cab with Jensens - sounded very close to a Twin.

[2bornot2bop]

Dedicated tube-o-phile here. Everything sounds better with tubes. If you're home playing, why do you need to worry about headroom? Turn your tube amp down, not up. There you go. BTW, all tubes are not created equal. The same tube amp stocked with a different variety of NOS tubes can take on a different character. That's the fun of owning a tube amp. At the end of the day, it's your preference that matters...sound is a personal matter...there is no "best" or "better."

[KirkP]

Here's a long detailed overview making the case that a properly defined Hifi SS amp and tube amp are indistinguishable as long as they aren't driven into distortion or limits of their power supplies. The reason guitarists generally prefer tube amps is that they like how respond when they are pushed, however slightly, into compression or distortion.
http://audioxpress.com/article/diffe...the-truth.html

[Spook410]

I don't use compression. I don't use distortion. I have good SS amps and a good tube amp. Tube sounds better. And my ears work fine.

[Greentone]

+1 jzucker on this point. My best sounding rig...and I have about 20, or so, amplifiers that I choose from--from 5 to 150 watts, tube and solid-state--is a tweed Fender Deluxe Amp with a Fender Reverb Unit, driven by a Heritage Super Eagle.

This setup is played very cleanly. The tone is incomparably full and jazzy. No solid-state amp...no other tube amp that I have...has the huge low end and silky high end of the Deluxe (tweed). Old Twin Reverbs will do the same--almost--but have a different tone stack. Old Ampeg Gemini amps will do this, too, and have a great tone stack.

I forsake my Polytones, my 4 x 10 Bassman, my tweed Pro, my Ampeg, my Gibson Lab Series L-5 (modified with a JBL D-130 15" speaker), etc., to play my tweed Deluxe amps.

I also greatly enjoy solid-state amps with carved-top guitars--e.g., Polytone, AI, and especially Evans. These amps sound super with carved guitars. The old Polytones and the Evans, especially sound warm and tube-like, to me.

Still, a few of the old tube amps sound even better. (1) Tweed Deluxe with just a tone knob; (2) Ampeg amps with baxandall tone stacks; (3) the Twin Reverb--if you set the tone carefully to suppress the scooped tone a bit.

Works for me.

[Chimera1to1]

i disagree with the original poster. To me , solid state amps are about convenience. A great tube amp operating within it's design efficiency parameters (i.e. not pushed past the limits of headroom internally or with its speaker) always sounds better to my ears. And the type of guitar doesn't really matter to me. A tube amp always sounds better.

However, there's a 3rd choice. A modeler such as the kemper which has the best of all worlds. Light and portable , extreme headroom but sounds like a tube amp.

Hey Jack,

I feel a bit divided. The OP felt that solidbodies went well with tube amps and I go along with that. And in that respect you and I agree too. Where I differ though, is that through my kemper I prefer a profile of a SS amp with my Eastman T146. The extra irony is the amp model is sitting in a cupboard. It's my Fender JazzKing. The profile sounds just like the amp but I prefer the sound via a good set of headphones or monitors. My own hunch is that I prefer the SS sound because i don't have the knowledge to effectively use simple chords. I default to a six string barre rather than an effective and efficient triad. My own experiences of seeing more experienced jazzers playing is that their comping may be refined down to economic chords that need less note separation so might sound better with tubes or a tube sim than with a SS amp.

Does this his tie in with your playing style? Ie you can say a lot with few notes..

[Greentone]

Chimera1to1,

You will want to get a Ted Greene book or something to learn your chord forms. Six-note grand barre chords sound really "cowboy" in a jazz context. They also have a tendency to step on everybody's toes in the rest of the rhythm section. Two note intervals and three note chords dropped in at the right moments are all the comping you need.

Archtops, truth be told, sound just fine straight into the board for jazz. I've recorded that way plenty with an ES-175 and no amp was needed at all.

Still, I like amps. I've played Eastman guitars through a silverface Fender Super Reverb. They sounded great. The Super Reverb makes a good, utilitarian amp for ANY kind of music...jazz, for sure. To be sure, though, your Eastman is going to sound fine through a good SS amp.

[John A.]

I don't use compression. I don't use distortion. I have good SS amps and a good tube amp. Tube sounds better. And my ears work fine.

You may not use compression or distortion as a deliberate effect, but every amp compresses and distorts to some extent, especially at the attack of a note and other transient peaks in amplitude in otherwise non-distorted operation. One of the theories (tons of publications purporting to demonstrate this) of why tubes sound better is that they preserve the waveform better under those conditions and to the extent that they do produce harmonic distortion, there's more even order harmonic content (which is perceived as more musical). In contrast, SS circuits tend to clip, rather than compress/preserve the waveform, with more odd-order harmonics. The research actually shows (in contrast to guitarist folklore) that under heavy distortion conditions tubes and SS are more similar to each other than under low distortion conditions (which I think probably explains why SS overdrive/distortion pedals can be perceived as sounding tube-y).

John

[boatheelmusic]

And don't overlook the Fender Mustang series - fully customizable tones, including adjustable sag and bias at a very reasonable price and weight compared to most other options.

[KirkP]

You may not use compression or distortion as a deliberate effect, but every amp compresses and distorts to some extent, especially at the attack of a note and other transient peaks in amplitude in otherwise non-distorted operation. ...

True. For example the tube rectifiers used in many tube amps (including Deluxe and Princeton Reverbs) cause the power supply voltage to drop as current draw increases, resulting in compression of all amplification stages. If the amp isn't being pushed hard this compression might be slight, but probably still has some influence on "feel" of the amp. Fender Twin Reverbs and Bandmasters use SS rectifiers, so have much less compression -- I think that gives them more of an "in your face" muscular response.
(Reference http://www.aikenamps.com/index.php/what-is-sag)
According to tube data sheets, total harmonic distortion (THD) of 6V6GT tubes in push pull configuration is around 5%. For 6L6GC that drops to 2%. That's under ideal conditions before component values drift. According to blind studies those THD numbers are barely detectable by the average person using normal program material. But when used for a single instrument (e.g. guitar) I think transients can easily push the THD higher into audible levels. This is just conjecture based on reading and occasional tweaking over the years.

Bottom line: Tube amp users are making use of compression and distortion to some degree, whether they realize it or not.

[bmw2002]

And don't overlook the Fender Mustang series - fully customizable tones, including adjustable sag and bias at a very reasonable price and weight compared to most other options.

Very interesting discussion. Would somebody please provide a layman's definition of "sag" (other than what I'm seeing in the mirror more often these days)?

[MaxTwang]

Very interesting discussion. Would somebody please provide a layman's definition of "sag" (other than what I'm seeing in the mirror more often these days)?

Sag is what happens when you temporarily put a higher electrical current demand on a tube rectifier than the rectifier can keep up with (the rectifier converts AC to DC). This causes the current in the amp to 'sag' or be temporarily starved until the rectifier catches up to demand. If you have your amp turned up and strum hard you may notice brief compression and possibly a little distortion - that's 'sag'.

Solid state rectifiers respond much quicker than tube rectifiers and tend not to experience sag. Different amps use different rectifier tubes, amps can be designed for more or less sag.


-----

To get a little more technical: Your pickups put out a very weak AC electrical signal (very low voltage, very low current), your amp amplifies that weak signal to low voltage high current that can drive a speaker. The tubes use DC to amplify the signal in the tubes: The 'heater' excites electrons, high DC voltage draws electrons to the anode, low or negative DC voltage on the cathode controls the flow of electrons to the anode (adjusting the voltage on the cathode is biasing), you may also have DC current applied to screens (which lay between the cathode and anode) which also tune the flow of electrons. When the amp 'sags' and the tubes do not have sufficient electrical current you throw your finely tuned tube out of whack causing what we observe to be compression and distortion.

Now you're asking "how does that discussion of tubes & DC cause my guitar's AC signal to be amplified?". Somewhere between the cathode and anode your guitar's signal is inserted into the tube and goes for a ride with those excited electrons up to the anode (where it exits the tube and goes on to the next tube or output transformer). When the amp sags - your ride through the tube gets a little bumpy & less predictable, and your signal is perceived as compressed, distorted, etc.

[bmw2002]

Sag is what happens when you temporarily put a higher electrical current demand on a tube rectifier than the rectifier can keep up with (the rectifier converts AC to DC). This causes the current in the amp to 'sag' or be temporarily starved until the rectifier catches up to demand. If you have your amp turned up and strum hard you may notice brief compression and possibly a little distortion - that's 'sag'.

Solid state rectifiers respond much quicker than tube rectifiers and tend not to experience sag. Different amps use different rectifier tubes, amps can be designed for more or less sag.

Thank you. So it sounds like "sag" really isn't a significantly contributing factor to "tubiness" other than at higher volumes, and not at all in tube amps that have a solid state rectifier?

[MaxTwang]

A tube amp can be designed to not sag; and a solid state amp can be designed to sag just like a tube rectified amp. These days it's up to the designer.

Old tweed amps tend to sag because the components used were designed to handle the electrical requirements when the amp was used as intended - no distortion; when people started to crank their amps, the amps were operating out-of-spec and distorted, compressed and sagged.

Also note that output transformers & alnico speakers can also contribute to compression and distortion which contribute to what we perceive as sag. Technically a power transformer can also contribute but mostly they get hot and start smoking when overtaxed. The cool thing these days is we have modern transformers and circuits that are designed to 'safely' distort, compress & sag without self-destructing.

[aleksandar]

It's interesting how these SS/Tube debates actually show yet another time that we are culturally conditioned creatures. I mean, we do standards, right? LP and Marshall, Tele and a Tweed or Twin, Carved (or even a semi) and a Polytone. One more thing that's interesting to me is how some people don't like transistor amps, but enjoy their Fuzz Faces, Rats, Boss DS/SD's.

But in the end, it's all about the music. For example, you always associate John Scofield with his Ibanez semi, RAT and a Polytone, but then all of a sudden you see him with a single coil Tele and a Vox and he still has that fat ratty nasty tone, although the vision looks skinny and plain wrong! Or you associate Mike Stern with his Tele, SS Yamaha and the other SS amp, chorused, delayed and distorted sound with a Boss distortion pedal, and then you see him with pair of Fenders and he still sounds like him.

I'd say is all about the overtones. Maybe the lack of overtones in a solidbody is compensated with the overtones of a tube. But I think that also the speaker and cabinet factor is neglected. I had a small 18W tube amp head that sounded enormous with a 4 X 10'' cab, and when I paired it with a small 6" speaker inside a thin plywood/plastic cabinet, it sounded almost as horrible as the SS amp that the said speaker went with.

Few years ago I had this old 150W SS amp with a head and a 15 inch cab. When I played it at home it sounded pretty decent. But when I played it on one gig, it was a true Gestapo amp, it chopped heads and the ears were bleeding no matter how I set it. So, not having another amp at that moment, for the gig the following day I brought a small solid state amp with a 1X10'' speaker that I made myself, with lots of experimenting, and I pretty much enjoyed playing it. Now I have a nice custom made tube amp that I also enjoy playing, but when I plug in into this small practice transistor amp, it's a nice change. The front end of that amplifier is similar to a RAT pedal design.

So, my point is, in my experience, the whole package counts, not just the tubes or the opamps or transistors, but the topology, design, the speaker, cab, effects, guitar, and last but not least, the fingers.

[Spook410]

Yes.. all amps compress and distort some small amount. However, running clean within the limits of the amps headroom, why is that germane in a musical context?

I'll be happy when I can have a 10 pound amp that sounds as good as my 60 lb Fender Concert but so far, we're not there.

[KirkP]

I've just trying to identify the possible factors causing SS amps to be typically perceived as falling short of even the cleanest high-headroom tube amps. I'm sure it's a combination of factors.
The possible factors I can think of:
- Differences in EQ/tone control design
- Distortion (here I include even minor distortion due to non-linearities, not necessarily the clipping that some of us object to)
- Compression (due to power supply limitations)
- Psychoacoustics (a dangerous topic, but it must be considered)
- Magical tube fairies or transistor gnomes
Did I miss anything? It's all about the music, but I still find it useful to understand the technical factors behind it.

[Greentone]

My best-sounding light amp is my tweed Deluxe. It sounds better--clean--than all of my other amps. I mean all of the other tube amps and all of the solid-state amps. It is as light as any of the solid-state amps, too. It is the go-to amp for gigs, unless I have to be loud enough to trump a big horn section...in which case I take my Lab Series L-5 (LOUD, LOUD, LOUD). I used to use my Polytone amps exclusively for the "less than Lab Series" gigs. Now, unless I plan on doubling on bass, I use the tweed Deluxe.

If you haven't played one of these (or a tweed Harvard) you simply don't know what you are missing.

[ESCC]

In very un-technical terms tubes give the sound a "dynamic" that I have never been able to replicate in a SS amp. I have 2 SS amps, 2 tube amps and a BK Butler RT955 2 channel tube preamp. I can get an excellent jazz tone in my SS amps, no complaints, however, if I put the tube preamp in front there is an undeniable additional dynamic (very un-technical) that can't be replicated without it, no matter how many different tweaks I make. I won't say flat out that the tubes are providing a better sound as much as there is an additional dimension to the sound that can't be captured in an SS amp, and the number of scotches I have when playing has no impact on this.