Is All Tube Worth It?

[jrfrond]

Speaking from a service standpoint, pure tube amps are less likely to spontaneously combust under stress. The flip side to that is that the tubes themselves aren't what they used to be, and THEY are more prone to spontaneous failure.

Solid-state, especially nowadays with all of the Class-D amps and neodymium speakers floating around, have a high power-to-weight ratio, and many of them, my favorite being MarkBass, sound excellent.

If you are willing to make the investment into pure tube amplification, count on new power tubes every so often. Most bass amps use 6550's, usually 4 or 6, and they aren't cheap. However, if you make the initial investment in NOS power tubes, you will save money and heartache in the long run.

My personal advice is this: play what you like, but ALWAYS try to keep a spare amp in tow, at least something light and cheap enough to get you through a gig. Component quality and manufacturing techniques aren't what they used to be, and failure on a gig can cost you. Something like those cheap little Crate Powerblock heads can work well in a pinch.

 

[LiquidMidnight]

I think this tube path can't touch solid state is worrying about purism to extremes. In a big show it's going to go through FOH SS anyhow.

...and any professional-level FOH equipment should be as transparent as possible and be able to replicate the original audio source, whether its tubes or solid-state, as authentically as possible. So I don't really understand what you're point would be. I don't know any sound engineers who use the gain structure of their PA systems to create saturation and tonal coloration like a guitarist or bassist does with their personal amp. That's like saying that all guitar and bass players should just DI to the mixing board in the studio, because most people's stereos have transistors.

But I know you're the resident crusader against tubes on the forum, so I don't know why I'm responding.

 

[Korladis]

this is why i can't ignore seamonkey. here is a guy who never ever touched an svt, sees diodes on the schematic, and thinks that's the only thing in the design that causes clipping, even though they're actually clamping diodes that control the voltage when you're already cranking it hard. way to keep trying to spread that uninformed misinformation, monkeysea.

Especially when I saw this particular talking point of his dissected and demonstrated to be misinformation just last week.

 

[JimmyM]

...and any professional-level FOH equipment should be as transparent as possible and be able to replicate the original audio source, whether its tubes or solid-state, as authentically as possible. So I don't really understand what you're point would be. I don't know any sound engineers who use the gain structure of their PA systems to create saturation and tonal coloration like a guitarist or bassist does with their personal amp. That's like saying that all guitar and bass players should just DI to the mixing board in the studio, because most people's stereos have transistors.

i don't see transparency and tubes as being mutually exclusive. voice the stuff to be near flat and it will be near flat. it can be done with tubes, as a lot of audiophiles with tube pre and power amps will tell you.

 

[agedhorse]

SVT's aren't all tube signal path. They have clipping diodes in the input of the amp section. These I'd expect to kick in at higher volume levels.

With the amount of voltage gain in the power amp, I would expect that the amp will begin to clip before the diodes. I see the diodes are there in part for input protection under extreme signal levels like fo some idiot plugging a power amp output into the SVT's power amp input.

 

[chadds]

Well, giving that this thread will appear next week, let me say this.
I'm old enough to have played all your favorite vintage stuff when it was new.
Fender, Sunn, Ampeg, Marshall and Hiwatt.
The first gen SS was horrible!!!!!!!!!!
Well smack dab in the '70s there was a SS Ampeg combo that had that tubiliciousness.
I know how 3D tubes can sound. At the gig they can behave differently. SS can give the pure punchiness consistently. The SVT cab gives that rig some of the control we call punchy.
On top of all this doo, the Glockenklang has all that 3rd 5th & 7th harmonic content that we love in the tubes.
Personally if it weren't for the Glock ( if you don't try it you won't know ) I prefer fat tube preamps like the Kern and Monique through real good SS power amps into worthy speaker cabs.

 

[seamonkey]

With the amount of voltage gain in the power amp, I would expect that the amp will begin to clip before the diodes. I see the diodes are there in part for input protection under extreme signal levels like fo some idiot plugging a power amp output into the SVT's power amp input.

You've seemed to have changed your position. No matter. Measurements will tell.

I don't think these diodes are sturdy enough to handle something as stupid as that. With too much current they would blow and leave the amp unprotected. Other tube amp schematics don't have any protection circuits like this. All the other manufacturers don't have this and don't seem to suffer from stupid user failure.

UncleFluffy was going to do some measurements to see when the diodes kick in. They may still kick in after the power amp clips, but that is still SS in the signal path for those who claim the real sound comes out when you crank an SVT.

With this configuration, the voltage levels into the amp seem very low without the diodes tripping.

If you bought home amplifier that claimed all tube path, but found these diodes on the circuit board and on the schematic, you would have a valid complaint for the FTC.

 

[LiquidMidnight]

i don't see transparency and tubes as being mutually exclusive. voice the stuff to be near flat and it will be near flat. it can be done with tubes, as a lot of audiophiles with tube pre and power amps will tell you.

Oh, I'm not disagreeing with you on that. I was just responding to Sea Monkey stating that adding solid-state power to the FOH adulterates the original tube source, so why use tubes in the first place. My point was that the idea of a pro-level FOH is to provide a transparent as possible amplification of the source; so the adulteration is rather minimal, since the audience are still going to be hearing the effects of the tube source from the mains.

Man, I just can't imagine the weight of the racks full of tube power amps that an average production company would have to carry around.

 

[Korladis]

Seamonkey: Obsessed with a couple diodes nobody else gives a crap about.

 

[seamonkey]

Oh, I'm not disagreeing with you on that. I was just responding to Sea Monkey stating that adding solid-state power to the FOH adulterates the original tube source, so why use tubes in the first place. My point was that the idea of a pro-level FOH is to provide a transparent as possible amplification of the source; so the adulteration is rather minimal, since the audience are still going to be hearing the effects of the tube source from the mains.

Man, I just can't imagine the weight of the racks full of tube power amps that an average production company would have to carry around.

That's right.
but no big tube amp needed. I made this point before, nobody every said you need a huge tube amp. A full tube path amp from input to transformer output can be made in a small package. This can be put through a reactive load, or a small isolated cab - like a headphone and mic.

And with all the pre-amps and hybrids - you'd expect that someone actually listen and did an a/b/x test to match that of a big tube amp.

Well there was a double blind study like 30 years ago with Tube versus Solid state for guitar amps and the guitarist couldn't tell a difference. IEEE peer reviewed paper presented at an IEEE conference. You can find it on the IEEE site.

 

[Calaverasgrande]

You've seemed to have changed your position. No matter. Measurements will tell.

I don't think these diodes are sturdy enough to handle something as stupid as that. With too much current they would blow and leave the amp unprotected. Other tube amp schematics don't have any protection circuits like this. All the other manufacturers don't have this and don't seem to suffer from stupid user failure.

UncleFluffy was going to do some measurements to see when the diodes kick in. They may still kick in after the power amp clips, but that is still SS in the signal path for those who claim the real sound comes out when you crank an SVT.

With this configuration, the voltage levels into the amp seem very low without the diodes tripping.

If you bought home amplifier that claimed all tube path, but found these diodes on the circuit board and on the schematic, you would have a valid complaint for the FTC.

Diodes are not a gain element. You can't make an amp out of diodes anymore than you could make an amp out of resistors.

 

[fdeck]

You've seemed to have changed your position. No matter. Measurements will tell.

Measurements should be unnecessary. It's a cathode feedback circuit. What's the gain equation? You only need to look at the front end of the circuit to figure this out.

 

[coreyfyfe]

Well there was a double blind study like 30 years ago with Tube versus Solid state for guitar amps and the guitarist couldn't tell a difference. IEEE peer reviewed paper presented at an IEEE conference. You can find it on the IEEE site.

Considering you said 30 years ago I'm assuming you mean this paper from April 1981, which says:

On tube vs solid state power amps: "A total of 12 subjects participated, resulting in a total of 54 trials. Four subjects did not report a difference in any trial. While eight of the remaining subjects reported hearing differences, seven were unable to identify the differences reliably. Reliable detection requires that the subject correctly identify the difference in amplifiers more than 50% of the time and not indicate a false difference. A false difference is reporting a difference even though A and B are assigned to the same amplifier. The remaining subject (subject #1) correctly identified the difference on two of three trials with no false differences."

On tube vs solid state power amps driven to distortion: "A total of six subjects participated, resulting in 23 trials. Three subjects did not report a difference on any trial. One of the remaining three subjects reported only false differences. The other two subjects were able to reliably detect a difference in sound. One of them was able to identify a "buzzing" sound which was more pronounced in the tube amplifier. He was able to detect this difference 100% of the time. It is interesting to note that this was subject #1 that detected a difference in test one. The other subject (#2) described the tube amp as sounding "fuller" two out of three times."

On tube vs solid state pre amps: "Five subjects participated, resulting in 24 trials. Two of the subjects did not report a difference on any trial. One subject reported only a false difference. The other two subjects could not reliably detect a difference."

On a full system, frequency and gain matched, power amps driven: "A total of 9 subjects participated, resulting in 49 trials. Three subjects did not report a difference on any trial. The remaining six subjects were unable to reliably detect a difference, including test subject #2 from the previous test. However, test subject #1 from the previous trials was unavailable."

Their final conclusion was: "Although ripple intermodulation distortion is easily detected by trained listeners, only one of seventeen test subjects was able to detect it without tranining. The change in frequency response caused by the high output impedance of the tube amp is by far the predominant cause for differences."

Or in other words, people who know what they're listening for, can hear the difference.

FWIW the test equipment was a twin reverb for the tube amp and a custom built pre-amp using 4558 op amps into a commercially available power amp.

 

[Count Bassie]

All-tube, depending on which one, I guess, is the schniz. I look forward to having one again... meanwhile I like the tightness and punch I'm getting from my old Trace Elliot AH250SMX. There's a tube to 'wool it up' in the front end, and the dual compressor in the chain is a great add. It actually almost gets "close"... but it is not it.

An all-tube head is in my future, I can tell. It's got that 'crush' thing going on... maybe it's not as tight-feeling as solid-state, but it lends itself to something with a very funky vibe, sound-wise.

SVT
Orange AD200
Trace VA400...

All different characters, but they share a characteristic. Definitely a 'class' of amp separate from SS or Hybrid. I will, in my heart never fully go back from it. In fact I'll BE back!

 

[Count Bassie]

...and right on the tail of Coreyfife's post! LOL! Oh well, shot myself in the proverbial foot I guess. But I know what I'm looking for/hearing, pretty much. And the truth is it really only matters to me, not the audience.

But if it takes tubes, and the 3+ years of saving up for them to inspire you, well, there you go!

 

[Bassdirty]

Or in other words, people who know what they're listening for, can hear the difference.

If they want to.(obviously, they know what they're listin for.)

The Title of this was "is it worth it?"

The answer is ..NO.
(tho I'm not 100% sure what is worth what.)
BUT, for ME, MY coverband...I guaranteee you, the chicks /(people)..but mostly chicks, dancin at my shows,with the music blaaaarin' kick drum kickin..makin em shakin the booty.
lotzo girls goin carazzy...lotzo guys wantin said girlz goin crazy...

At my shows..IME..SWR 410..just loud nuff for stage volume..maaaajor bass hammerin thru the (paid)soundguys wall o sound...

NO.
For me, it's not worth it.
I donn't mind the sound of a real tube amp..but seriously, in a mix,live,covertunes,..come on folks.
When I play for a crowd of 7,000 Talkbassers, then we'll talk,
Until then..it aint worth...IT...(to me,YMMV..bla ,bla..IMO..)

Not trying to offend those who spend alot of $$ for a tone that a hot groupie can't hear the difference on



.
sorry
1030+2 glass wine +1 rumn coke=....well u know

 

[seamonkey]

Or in other words, people who know what they're listening for, can hear the difference.

One trained listener out of many was able to detect artifacts that had no productive contribution to the sound. Like rumble and crackle on LP's. If you fixed the tube amp, he wouldn't be able to tell.

 

[sethlow3]

Solid State makes for an easier life... Plus people who aren't musicians hardly notice... A great player is a great player regardless of amp.

 

[seamonkey]

Measurements should be unnecessary. It's a cathode feedback circuit. What's the gain equation? You only need to look at the front end of the circuit to figure this out.

Or you can model it in ltspice
Voltage drop for a silicon diode is .7V but they start to break over at lower voltages. That's pretty low for a power amplifier input.
Surprising that no other amp manufacturer came up with such a circuit for "protection"

 

[Count Bassie]

Solid State makes for an easier life... Plus people who aren't musicians hardly notice... A great player is a great player regardless of amp.

Truth.

Truth is, at the end of the day, I mostly don't care too much what I play through. I care what bass I'm playing.

But...