Solid state/class d vs tube amps

[dukeorock]

There's such a thing as too much garlic?

I’d much rather fight about this for the next 24 pages

 

[lowplaces]

ok guys. As generic of a topic as this is I have a big dilemma.

If you check my sig, you will see that I am a (proud) owner of Aguilar amps.

They sound great and all but yesterday I tried to hook up a fender bassman tube clone.

Wow! I couldn't believe the sound I was getting. Barefaced big twin 2 has a renown of being a cab that is able to pump monstrous lows, that are sometimes even hard to control. But with the clone, every low note has a clear and round, veery warm low end that doesn't extend over the limits. What surprised me even more is that every note I played, even on higher registers is still meaty and has a great low mid presence and just keeps on going and seamlessly blends with the low notes with zero volume difference.

My aguilar amps work great as well but there was an obvious and immediate difference in the sound the moment I plugged in.

I immediately felt groovier and a better bass player.

Should I go after an all tube amp? I never played a solidstate with a similar warmth and meat to the sound and I am starting to think I never will.

The bassman clone was 40w and I couldn't believe how loud it actually was.

The size of these amps is bugging me though.

I can totally relate.

When I got back into playing bass I bought a Rumble 500 head. I was very happy with it and thought it sounded great. Then one of these popped up on the local Craigslist.

I found that image of the old ad for these amps and noticed the description. Bass, organ, or guitar with a sealed cab within the combo.

Grabbed my bass and went to check it out. 50 watts of sweetness I never heard through my Rumble. I was so close to buying it until I went to pick it up. It felt heavier than a Fender Twin Reverb !

The seller told me it was cool to go home and think about it.

So I went home and fired up my Rumble. The tone I heard through that Guild just wasn't there. I had to have a tube amp and when Ampeg announced the rebate on the PF line I bought a PF-50T head.

Love them ! (I bought a second one.... just because.. )

 

[bobyoung53]

I love Judy Garland's voice. In 1989 I did a roadshow tour (CA stops) for MGM Classics of the newly restored Wizard of Oz in celebration of the 50th anniversary (back in my cinema support days). Beautiful 35mm 3 stripe Technicolor print, larger cinema venues. I used some of Judy's other music for walk-in. She had such range and emotion in her voice and the arrangements really supported her.

If you are a WOZ fan, there was a musical number that was not used in the picture and remained fairly unknown until sometime around the 50th anniv. It was quite racy for the time, has elements of what is now known as Beat, or even Hip Hop. There's a great upright bass arrangement it this song, it's mixed pretty up front and in your face (for the era). Well worth listening to IMO just for what it represented. You won't typically hear bass mixed this forward in film scores of this era because low frequencies on film were limited by the width of the sound track (minus the bias line or lines in the case of duplex tracks) on the film for variable area tracks. What's ironic is that the visual representation of the audio on modern recording software packages is essentially the same as variable area track representation on film. As dynamic range improved (finer grain films, smaller scanning slits, PV cells replacing PE cells, quieter electronics, and Dolby A NR, higher power handling speakers, subwoofers (first used with the Dolby CP-50 and CP-100 processors), it was possible to improve low frequency dynamic range as well as high frequency extension. This is why bass (kick and gtr) have grown in prominence in more modern mixes. Of course the shift to digital audio (fiorst TDS, then DTS, SDDS and Dolby Digital) made sound on film limitations a moot point.



Enough of the OT stuff, though it really is bass oriented.

There's a guitar playing an octave up in unison with the bass at the beginning of the song too making it even more prominent but yeah it is mixed way up there for that era, sounds good. Man those two singers have great timing.

 

[DavesnothereCA]

Thanks for the informative post. I could be wrong but I believe you may have taken this out of context.

When I meant odd order harmonics, I was referring (and I think ThisBass may have been as well) to the make up of a single note and it's harmonic content as analyzed by a Fourier series.

The more "square" a signal becomes due to saturation of active devices as they near B+, Vdd or Vcc the more augmented it's odd order harmonic content becomes.

~
I'm not familiar with the Fourier reference (will look that up though), but I agree that a square wave, however generated, contains more odd-order harmonic content.

Not sure where I learned that decades ago, but somebody taught me.

It's possible that we all might be saying the same thing in different ways.

EDIT :

Fourier series - Wikipedia

The above link has some neat animations which demonstrate what the fancy trig formulae represent, comparing even vs odd order reinforcements, producing either a square or a sawtooth wave.
~

 

[Rodslinger]

I admit I based my point of view on my feelings, but also on the last Metallica's rig rundown where both guitar techs explain they only now use AxeFx and Matrix SS power amp.
Because "it's way more reliable, always sounds the same and can handle heavy touring, unlike tube amps"

The band "Periphery" was using AxeFX for years too. They recently went back to Tube Amps because they said nothing could compare to the sound and tone of an all tube amp. These were Mark Holcombs (guitarist) exact words when I talked to him at a Sam Ash guitar clinic.

 

[baxter_x]

The band "Periphery" was using AxeFX for years too. They recently went back to Tube Amps because they said nothing could compare to the sound and tone of an all tube amp. These were Mark Holcombs (guitarist) exact words when I talked to him at a Sam Ash guitar clinic.

Thanks for this great feedback.

 

[somebrains]

The band "Periphery" was using AxeFX for years too. They recently went back to Tube Amps because they said nothing could compare to the sound and tone of an all tube amp. These were Mark Holcombs (guitarist) exact words when I talked to him at a Sam Ash guitar clinic.

Did Periphery and Metallica flip sponsors?
I like racing too, and I ain't buying anything Danica Patrick uses.

 

[baxter_x]

It seems to me that many people use those AxeFX as it's easier to carry around. But after a while they all seem to come back to the real thing again. I might be wrong but I've heard the same story before

 

[agedhorse]

It seems to me that many people use those AxeFX as it's easier to carry around. But after a while they all seem to come back to the real thing again. I might be wrong but I've heard the same story before

Correct, you might be wrong on this. The stories and the truth are often not the same, especially on the internet.

 

[baxter_x]

Correct, you might be wrong on this. The stories and the truth are often not the same, especially on the internet.

OK, then I urge Fractal to make an AxeFX for bass players!

Also, one of the guitar player of my band got rid of his entire "real thing" for an AxeFX. He says he will probably never go back to a "real" amp. He has everything he wants and even more in a single lightweight device.

 

[RedJag]

Mike Kerr from Royal Blood uses Bassmans for his bass tone.

 

[Cuzzie]

I didn’t get proper views but I am
Pretty sure he has some form of multi FX unit now looking at how he uses it and the lights, his complex octavers, kill switches etc. Have gone.

Sooner or later Line6 Helix and Fractal AX8 will practically nail it, won’t be everyone’s cuppa, by they will be mighty mighty close.

 

[xk49w]

The band "Periphery" was using AxeFX for years too. They recently went back to Tube Amps because they said nothing could compare to the sound and tone of an all tube amp. These were Mark Holcombs (guitarist) exact words when I talked to him at a Sam Ash guitar clinic.

I wonder if he's tried a Kemper? There are touring professionals using it now.

 

[Rodslinger]

OK, then I urge Fractal to make an AxeFX for bass players!

Also, one of the guitar

OK, then I urge Fractal to make an AxeFX for bass players!

Also, one of the guitar player of my band got rid of his entire "real thing" for an AxeFX. He says he will probably never go back to a "real" amp. He has everything he wants and even more in a single lightweight device.

My guitarist moved to Quilter Power Amps and pedals. He just brings his pedal board and cabinet to shows. He says he will keep his Tube amps for recording. We shall see how long it last because his sound is thinner & one dimensional right now. With the tubes it was thick, lush & 3D

 

[somebrains]

I still have to keep more than 1 amp around, just like I need more than 1 pair of shoes.
No one is paying me to rock designer Converse with a tuxedo and a tshirt at the Oscars.

 

[FunkHead]

Hey! ........Why do they have to be so big and heavy??

I wear my bass on a strap and put my Tube head on top of my Cabs. Not the other way around.

 

[AE1]

~
OK, it could have been some other factor which the lead players like about the way in which tube amps broke up when pushed, but that was what anecdotally reached me at the time.

And as I am sure that you recall, companies came out with dummy load boxes (such as from Altair and Tom Scholz), to let a player variably dial down the final volume to the speaker while pushing a power stage just the right amount, whatever THAT was. ~

Here is an attempt at one explanation option

IMHO, might have something to do with the control grids (G1) being driven positive in a Class AB tube amp fixed bias system

All power tubes draw low levels of control grid (G1) current due to tiny levels of residual gas in the tube - i.e. an imperfect vacuum

In the case of typical power tubes as used in guitar and bass amps, when the grid voltage approaches zero in a push-pull power tube stage the grids commence to lose control over plate current, causing the tubes to move towards the Class B region of operation. This change rapidly increases distortion because the positive signal plate current is no longer directly proportional to the signal - ie linearity is lost.

At that amplitude of signal swing drive voltage the opposite negative swing signal will most likely cutoff the tube altogether, resulting in true Class B

When progressively driven further positive above zero, the positive grid voltage increases to a more positive potential than the real cathode, causing the metal grid electrodes to become a "virtual cathode" alongside the real cathode, thereby also supplying the plates with DC grid current drawn directly from the fixed bias supply. This causes a positive voltage drop across the grid resistors, offsetting the negative bias, and further increasing plate current

At the same time, the limited AC signal current from the preceding driver stage, which normally controls the bias voltage, diminishes its capacity to control drive bias, also increasing distortion.

A sign of this malfunction is burned out grid resistors - common in some brands - resulting in complete loss of bias and potential self-destruction of the associated power tube

At the same time as all the above, because plate current is now excessive, the power supply is likely to lose its capacity to maintain plate voltage and/or current (sag). Tube rectifier power supplies typically sag earlier than solid state. As the power supply voltage progressively decreases, the capacity of the power tubes to deliver power also decreases, causing the whole output system to collapse in a heap.

Most guitar and bass tube amp fixed bias supplies are half-wave with limited low current capacity so when overloaded they quickly lose their capability to maintain bias voltage at the source

So what you have is the supply end of the bias resistors at less negative potential caused by bias power supply sag and the other end (G1) at less negative potential caused by grid current passing through the bias resistor - both interactively causing an increase in plate current

Add all the above in the mix with an undersized power transformer and output transformer and you get a wide range of design options for manipulating the behaviour of the tube amp power stage

Amp designers have no control over individual tube characteristics so it would be unreasonable to expect them to design for unlimited grid current needs in a conventional guitar or bass amp. Even if they did, the player could just crank up the volume a bit further to replicate the same overload condition

So players, the power is in your hands

 

[agedhorse]

Except that on a properly designed amp, load boxes, power soaks, and such devices are used all the time without any of the issues that you are postulation.

You are trying WAY too hard.

 

[bouncy]

First of all, I am a die hard tube amp fan. There is nothing wrong with D class amp with those super light weigh cab, it is different approach to meet the need of the market. It is also the trend of modern world, amp is much cheaper to make, much affordable, if it breaks down, just replace it, labor is so expensive. SVT type high power head is probably the best compromise to meet the market need. High power, lower the production cost by making it outside USA. IMO, it isn't the best example to showcase what tube amp sound is. On top of that, they are still expensive, heavy and it can be a real pain to service because of the pcb. Most people will not hesitate to drop $ 600 every 3-4 years to get a new phone, but spending same money to retube and service a tube amp, it is a different story.

If anyone interest to explore the real tube tone, try a low watt tube amp, somewhere around 50W to 100w, match it with vintage speakers like JBL or Altec, or old EVs, then you will know why old folks like me will never give up using tube amp. By saying that, it is also depend on your musical taste, too.

Cheers

 

[seamonkey]

Sooner or later Line6 Helix and Fractal AX8 will practically nail it, won’t be everyone’s cuppa, by they will be mighty mighty close.

Those, and many more have already nailed it ... for years. Modeling and plugins are big business and used all over the place. They are very popular in the studio and stage. Sometimes, progress is "progress".

Namm is just around the corner, expect even more entries in this field. For those who find comfort in something that looks like a "head" there are ones built that are essentially a PC in head case, but with no access to the OS by the user. It you have a open mind and and are OK to other form factors, there are a giant number of options.