[Cirofost]

Hey Head-Fi, lately I've been getting into the world of tube headphone amplifiers, and I have a few basic questions I can't find a straight answer for.
 
If I buy a $100 tube amp that has a single small tube, will I be able to take out the tube and swap it for a better higher quality one? If so, how?
 
What are the reference and most known tubes? How do the sound characteristics change from one another?
 
Are there different uniform sizes of tubes? I.e., number of pins, number of tetrodes? (Speaking of tetrodes, what are they? What do they do?)
 
I realize the main characteristic of tube amps is a warm life-like bassy sound, so with that in mind, would it make a bright and analytical headphone more neutral and enjoyable to listen to with rock music?
 
That's all the questions I have now, but I might come up with more.
 
And thank you in advance fellow head-fi'ers for helping me on my quest of tube amps!
I realize everybody has to start somewhere, so why not form the masters at head-fi!

 

[p a t r i c k]

I used to use valve amplifiers with loudspeakers years ago but I don't use valve amps at all today. (In the US you call valve amplifiers "tube amplifiers").
 
Whatever valve amplifier you buy there will be a number of compatible valves that you could install. For different valve the number of available alternative compatible valves varies.
 
In your question though I see something that is worth addressing. You wonder if you can replace the valve that comes with the amp with a better one. Well, the answer is, possibly. However the quality of the valve is one part of the whole amplifier design, so you might not get any benefits so easily. Other factors are the transformers, the power supply, in fact all aspects of the amplifier.
 
Personally I would not be optimistic about the sound quality of a budget valve amplifier, and I don't think it would be remedied by simply replacing the valve.
 
My own opinion is that in order for valve amplifiers to perform well in a Hi Fi they need to be expensive.
 
Solid state amplifiers can perform extremely well at budget prices.
 
If you are looking for natural "life like" sound then this can be achieved with Class A solid state amplifiers which imho can produce the most life like sound of them all. However Class A solid state amplifiers tend to cost a bit of money, but it is within reason. Class A solid state amps are prone to a little bit of "warmth" but nothing like as much as valve amplifiers. It is my belief that amplifiers should not add anything to the sound, so less warmth is better.

 

[jpcollinsworth]

I am basically in the same camp as you. I've only been using headphones and lurking here for about a month. I'm listening with a pair of Audio Technica ATH-ESW9's using an iPod as the source running through an inexpensive 1-tube class A amp, a Bellai HA540. I read through the Bellari tube-rolling thread and picked up a used 1951 Telefunken from a seller on Ebay. Although I believe I can hear an improvement over the original tube, it's entirely subjective. I listen to a lot of jazz it appears to be a good match to me.

 

[Cirofost]

Thank you both for the responses. The amp I was looking at is the Bravo Audio Ocean. It is $130, but it is "Class A" And most reviews say it sounds really nice and has a good gain. It also has a SNR of over 90db, has frequency capabilities of 10hz to 60khz, and can support headphones from 20ohms to 600ohms.
The tube, or valve it comes with is the 12AU7. I'm not sure if that's known to be good or average, but it seems to be the default for many amps of this size. It also has an aluminum housing which acts like a heat plate, but heat is something I don't worry too much about, since it's always cold up here in Wisconsin.
 
I also plan to be using the Asus Xonar Essence ST as the source (playing lossless 24-bit flac or wavs in oversampled 176.4 through foobar), and the headphones being the Sony MDR-SA3000. The SA3000 is known for being a bit on the bright side, so I want to get something I can afford that would help even it out and make it sound better over-all.
 
What are you thoughts on this? Do you think it will sound good?
 
Thanks again in advance for all the help and advice!
 
[EDIT: The Sony MDR-SA3000 has an impedance of 70ohms, has the frequency capabilities of 8hz - 100,000hz, has a sensitivity of 100db/mw, and can handle a total power of 1,500mw.]

 

[Cirofost]

Anybody know if this set-up will work well?

 

[monousa]

This little tube hybrid amp has a wonderful sound signature. I am using it to amplify my IPad which is connected to a Hidizs 8. Then sending the Hidiz8 output to the Rockville Tubehead. I’ve been listening through various Grado Headphones. Sr125. SR325..Gw100 in wired mode. The sound is outstanding to my ears. Using Amazon HD music. Every song I tried sounded very true. In other words , a cymbal sounded real. A bass guitar sounded as it is supposed to. Correct pitch. Amazing. This combo has made my Grado’s sound the best ever. Everything is very natural. And the Rockville doesn’t need to be maxed out at all. I was listening to 70’s rock and some classical music. Just amazing what this Tubehead can do for amplification. The Tubehead makes everything centered. I can highly recommend. The Tubehead has two inputs. A 3.5 mm and rca stereo left and right. I plan to use it with my closed back Marshall Monitors as well as my Bose qc25’s next. I’ll let you know.
https://www.amazon.com/dp/B084D1V3P2?ref=cm_sw_em_r_rw_mw_n7TnwHHQjgx9

 

[thomaskong78]

I recommend you to try

https://www.soundandvision.com/content/tube-amps-pocket-change-nobsound-ns-08e
fitted with Nos Sylvania JAN CHS 6AK5 tube sound fantastic with HD 800s.

It cost me around 100 bucks including Nos tube and adapter.

https://www.amazon.com/Nobsound-NS-08E-Integrated-Amplifier-Headphone/dp/B014FASL1A

https://www.ebay.com/itm/2-Sylvania...346897?hash=item594424b9d1:g:IBgAAOSwkW5eMMvg

https://www.amazon.com/gp/product/B078X85LFS/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1