[Phos]

I've heard a bunch of descriptions of how tube amps differ from solid state amps, but what do they do to the ultimately frequency response?  I'm not sure if it's for me or not.  

 

[Phos]

I hope no one minds me bumping this, But I don't have any reference for how a tube amp sounds compared to a solid state amp.

 

[Uncle Erik]

There isn't a reference. Solid state amps are different from each other and so are tube amps. There isn't a generic tube amp and solid state amp you can compare. There are so many factors that you can't compare the two.

As for frequency response, tubes can easily pull 20Hz-20kHz. IIRC, the Zana Deux has headroom all the way out to 60kHz.

There are many other factors, as well. Like the output impedance of a tube amp. No matter the frequency response, a high or low output impedance will cause different headphones to behave differently. The power supply is hugely important, too. If you have a poorly implemented power supply, it can add a little AC ripple to what you're hearing. Build quality is important, too. Badly built tube amps will require a lot more service than a well-built one.

Same goes for solid state's build quality. The chips can run hot and the amp will kill itself unless built properly.

I assume you're trying to find an amp to buy. If you're looking to save money, buy solid state. Solid state can be done very well for not much money. This is because transformers aren't as expensive, and the fabrication and casing require less labor. If you want tubes done right, you either have to pay for it or do it yourself.

 

[mulveling]

Agreed. Interesting side note - I've got a pair of Heathkit W5 tube amps (for speakers) that were manufactured in the late 1950's - based on a circuit design from the late 1940's - and its manual shows measurements that are essentially ruler-flat from 10Hz-100,000Hz (!!) @ 5 Watts of output. A well-engineered tube amp need not display significant frequency aberrations, or rolloff, of any kind. 
 
However, like Erik said - don't cheap out when it comes to tube amps. A poor design, or even a decent design in the wrong application, will usually give poor results.

 

[KingStyles]

Tube amps can change depending on what tubes are put into them. By rolling tubes you can make some tube amps ss sounding or tubey, extended or rolled off, tipped up highs or warm. The frequency responce can vary greatly. I have to agree with the others that unless you want to tie up a significant amount of money to get a quality tube amp and the money it takes to roll tubes to find the sound or frequency response you like, a ss amp may be the best option.

 

[Uncle Erik]

Tuberolling is minor when compared to the actual circuit.

 

[KingStyles]

 
Quote:

Tuberolling is minor when compared to the actual circuit.

True, but it is an added expense that should be thought about before you buy. Having the right topology/circuit design is important especially when trying to match the headphones to the topology among other reasons.

 

[Graphicism]

Quote:

Tuberolling is minor when compared to the actual circuit.

I disagree, the tubes are the sound, likewise op-amps are the sound. In terms of headphones; the tubes are the speakers and the circuits are the cables.

 

[Lan647]

Question: If I have an amp with a frequency response from 15hz, will this mean I won't get the sub-bass from headphones stretching further down than that, like the LCD-2??? 

 

[Lan647]

Please answer

 

[Uncle Erik]

 
Quote:

I disagree, the tubes are the sound, likewise op-amps are the sound. In terms of headphones; the tubes are the speakers and the circuits are the cables.

Then what if you change the tube's bias and make it non-linear in a noticeable way?  How about using a fantastic tube in class B?  That wouldn't sound very good.  Or how about a wretched power supply that introduces AC hum into the circuit?  I could go on.
 
Tubes only perform as well as the circuit allows them to.  A mediocre tube in a great circuit will sound good.  The best tube in a bad circuit will sound bad.
 
Try it yourself.  Find an old tube AM radio and put the finest tube you can find in the output section.  See what happens.
 
Lan647, what that usually means is that the amp rolls off below 15Hz, not a hard shelf.  Howver, most recordings cut off below 20Hz; you would need something like SACD or DVD-A for a recording that has information below 20Hz.  Even then, information below 20Hz might have been cut out in the studio.

 

[attenuated 3db]

Quote:

I've heard a bunch of descriptions of how tube amps differ from solid state amps, but what do they do to the ultimately frequency response?  I'm not sure if it's for me or not.  

 
There are so many generalizations about how tube ampilfiers differ from solid-state amps that I have found this web page to be the best one-page, unbiased scientific summary of the differences:
 
http://www.theaudioarchive.com/TAA_Resources_Tubes_versus_Solid_State.htm
 
As with the success of a retail establishment being based on "location, location and location," the success of any particular tube or solid-state amplifier is in "implementation, implementation and implementation..."
 

 
 
 

 

[Grado77]

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[Lan647]

Quote:

 
Lan647, what that usually means is that the amp rolls off below 15Hz, not a hard shelf.  Howver, most recordings cut off below 20Hz; you would need something like SACD or DVD-A for a recording that has information below 20Hz.  Even then, information below 20Hz might have been cut out in the studio.

Well thats good news I use some high-res recordings though, but maybe that still ain't SACD level in terms of frequency extension and information? 
 

 

[nikongod]

You would probably be amazed how few recordings have information down to 20hz at all, regardless of medium or recording technique. Very few instruments go to 20hz, and very few recordings have anything below 50-60hz. 
 
Having a system that goes below 20hz is nice for a few reasons, but the most important is not "to play 20hz" in your music. The reason you want WIDE frequency bandwidth is that weird things start happening a couple octaves before the -3db points.