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Amps that Need only One Tube v.s. Amps that Need more than One Tube?

post #1 of 15
Thread Starter 

Hi guys, I am now tube amp-less and thus am planning for my next move (i.e. should I buy back same model or...?)

 

I noticed that the market has amps that need only one tube (e.g. 12AU7) and amps that need more than one tube.

 

Is there any difference between them and what should I (not) care about those cases?

 

Thanks!

post #2 of 15

Generally amps with only one tube are hybrid amplifiers, but choosing an amp is not a five minutes job, what headphones will you use ? what headphones did you plan to buy ? and what is your source (DAC, CD player, mp3 player, etc..) ?

post #3 of 15
Thread Starter 
Ah I see, so if I really want the tube sound I have to go for those pure tube amps that need more than one tube?

Also, silly me, I forgot to mention my setup. I am currently using my laptop's optical out to a Fiio D03K Taishan (which has RCA outputs and 3.5mm output). I am using my Beyerdynamics Custom One Pro and might go for HD650/AKG702 in the near future.
post #4 of 15
Quote:
Originally Posted by darkarn View Post

Ah I see, so if I really want the tube sound I have to go for those pure tube amps that need more than one tube?

Also, silly me, I forgot to mention my setup. I am currently using my laptop's optical out to a Fiio D03K Taishan (which has RCA outputs and 3.5mm output). I am using my Beyerdynamics Custom One Pro and might go for HD650/AKG702 in the near future.

 

There's no really "tube" sound, some amps can have a 100% tube sound and can have a very lean and neutral sounding and some SS or transistor amps can have a really warm sound, if you're interested only in power hungry cans like HD650 the best bet is an tube OTL design, but i think that hybrid amps are more versatile and allows you to own several kind of headphones (vintage AKG, Grado, HD-650, 600 Ohm Beyer).

post #5 of 15
Thread Starter 

I see, so once again it's a matter of what my ears approve the most at the set price? :X

 

I don't get how hybrid amps can be more versatile though; is it something about too much/little gain?

post #6 of 15
Quote:
Originally Posted by darkarn View Post

I see, so once again it's a matter of what my ears approve the most at the set price? :X

 

I don't get how hybrid amps can be more versatile though; is it something about too much/little gain?


OTL is most of the time high volts and low current. While it's good for 300 ohms and 600 ohms cans, it's current output isn't enough for low sensibility 50 ohms cans.

Hybrid uses most of the time tube as input and solid state as output to push massive amount of current. Thus, this type of design will be able to drive a wider variety of headphones.

post #7 of 15

hd650 require higher V drive - not particualrly "power hungry" though

 

the K701/2 are lower efficiency which is measured in dB/mW, and lower Z - they require more current and power but a little less V than the HD650

 

single tube dual triode hybrids are the cheapest if you want any tubes in the circuit

 

all tube amps often use stepdown transformers - good audio output stepdown transformers cost OEM $50-100 for 2  - so don't expect good ones in amps selling less than $500

post #8 of 15

Sounds like a good hybrid is in your future. 

post #9 of 15
Thread Starter 
Quote:
Originally Posted by Rem0o View Post


OTL is most of the time high volts and low current. While it's good for 300 ohms and 600 ohms cans, it's current output isn't enough for low sensibility 50 ohms cans.

Hybrid uses most of the time tube as input and solid state as output to push massive amount of current. Thus, this type of design will be able to drive a wider variety of headphones.

 

Ah I see... And I thought you will need less current for those 50 ohms cans :X

 

Quote:
Originally Posted by jcx View Post

hd650 require higher V drive - not particualrly "power hungry" though

 

the K701/2 are lower efficiency which is measured in dB/mW, and lower Z - they require more current and power but a little less V than the HD650

 

single tube dual triode hybrids are the cheapest if you want any tubes in the circuit

 

all tube amps often use stepdown transformers - good audio output stepdown transformers cost OEM $50-100 for 2  - so don't expect good ones in amps selling less than $500

 

Errr sorry, what's a stepdown transformer? Is it in the supplied PSU?

 

Quote:
Originally Posted by mvrk10256 View Post

Sounds like a good hybrid is in your future. 

 

Hmmm... Very likely... ;)

post #10 of 15

tube amps need at least one line power transformer and then may have an output transformer/ch - often all are of similar size, appearance when bolted in view on the top of a "classic" tube amp chassis design

 

some add power filter chokes of near the same size, external appearance as the other transformers

 

the audio output transformers take the I,V tubes may be happy operating at - say 100 V, 20 mA rms and transforms it to say 10 V, 200 mA rms  that would drive many headphones better

 

but to do so over the whole audio range, with low added distortion, good quality audio output transformers use much more expensive materials and assembly techniques than line power transformers


Edited by jcx - 7/12/13 at 1:06pm
post #11 of 15
If you want great DAC/Amp combo with tube amp for HD650 get Woo Audio WA7. I know it's not cheap but it really good pairing with many other headphones such as T90 and t1
post #12 of 15
Thread Starter 
Quote:
Originally Posted by jcx View Post

tube amps need at least one line power transformer and then may have an output transformer/ch - often all are of similar size, appearance when bolted in view on the top of a "classic" tube amp chassis design

 

some add power filter chokes of near the same size, external appearance as the other transformers

 

the audio output transformers take the I,V tubes may be happy operating at - say 100 V, 20 mA rms and transforms it to say 10 V, 200 mA rms  that would drive many headphones better

 

but to do so over the whole audio range, with low added distortion, good quality audio output transformers use much more expensive materials and assembly techniques than line power transformers

 

Any examples of them? :X

 

Quote:
Originally Posted by olegausany View Post

If you want great DAC/Amp combo with tube amp for HD650 get Woo Audio WA7. I know it's not cheap but it really good pairing with many other headphones such as T90 and t1

 

That's really out of my budget! :O And I prefer optical out over USB out...

post #13 of 15

I'm also looking to try a tube amp for the first time and am having to read up on what is available. I don't have the ability to demo before purchasing so it is going to be pot luck I guess.  Here are a couple of options that I'm investigating and you may also find the links helpful:

 

  • Analog Squared Paper is a one person Japanese business that currently makes two beautifully constructed amps: TU-05 and the smaller in dimensions hybrid TUR-06.  There is a very active thread on Head-Fi which gives heaps of information and the participants are real enthusiasts.  http://www.analog2p.com/index.html

 

  • These are DIY hybrid tube amps but they also provide the opportunity to purchase them fully assembled at reasonable cost. For a beginner like me they look like a good option to find out what all the fuss is about tubes. Part of the fun is rolling / trying different tube(s) combinations.  I'm seriously thinking about their latest "Project Ember" amp as it allows you to roll dozens of different tube types and the amp handles the biasing automatically.  http://www.garage1217.com/index.html

 

Good luck with finding something suitable for you.

post #14 of 15
Thread Starter 
Quote:
Originally Posted by TIMITS View Post

I'm also looking to try a tube amp for the first time and am having to read up on what is available. I don't have the ability to demo before purchasing so it is going to be pot luck I guess.  Here are a couple of options that I'm investigating and you may also find the links helpful:

 

  • Analog Squared Paper is a one person Japanese business that currently makes two beautifully constructed amps: TU-05 and the smaller in dimensions hybrid TUR-06.  There is a very active thread on Head-Fi which gives heaps of information and the participants are real enthusiasts.  http://www.analog2p.com/index.html

 

  • These are DIY hybrid tube amps but they also provide the opportunity to purchase them fully assembled at reasonable cost. For a beginner like me they look like a good option to find out what all the fuss is about tubes. Part of the fun is rolling / trying different tube(s) combinations.  I'm seriously thinking about their latest "Project Ember" amp as it allows you to roll dozens of different tube types and the amp handles the biasing automatically.  http://www.garage1217.com/index.html

 

Good luck with finding something suitable for you.

Thanks for the heads up for the Analog Squared Paper, now that's what I call a portable tube amp! I am not sure if I want it now as I am still trying to figure out the tubes it can use.

 

And yes, I am strongly considering the garage1217's amps too; if I don't see any good second-hand deals locally (Singapore), I will most probably get one of them.

post #15 of 15
Quote:
Originally Posted by TIMITS View Post

I'm also looking to try a tube amp for the first time and am having to read up on what is available. I don't have the ability to demo before purchasing so it is going to be pot luck I guess.  Here are a couple of options that I'm investigating and you may also find the links helpful:

 

  • Analog Squared Paper is a one person Japanese business that currently makes two beautifully constructed amps: TU-05 and the smaller in dimensions hybrid TUR-06.  There is a very active thread on Head-Fi which gives heaps of information and the participants are real enthusiasts.  http://www.analog2p.com/index.html

 

  • These are DIY hybrid tube amps but they also provide the opportunity to purchase them fully assembled at reasonable cost. For a beginner like me they look like a good option to find out what all the fuss is about tubes. Part of the fun is rolling / trying different tube(s) combinations.  I'm seriously thinking about their latest "Project Ember" amp as it allows you to roll dozens of different tube types and the amp handles the biasing automatically.  http://www.garage1217.com/index.html

 

Good luck with finding something suitable for you.

 

imo if you don't need autobias, strong power and preamp output imo the best option is the Project Starlight..

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