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Explain the use and benefits of tube amps? - Page 5

post #61 of 98
Quote:
Originally Posted by vkalia View Post
 

 

Yes, thank you, that sums it up very nicely.    It is far TOO easy to explain away any difference of opinion by just saying "well, I hear things differently".   Ok, that is fine, but at some point, in order to design a better product, you need science.    Otherwise, there will be (and already are) far too many naked emperors walking around (the one that offends me the most is the Shakti Stone).   But at the same time, the science has to be guided correctly - ie, if we are going to measure X, Y and Z when deciding on "quality", then we need to first prove that X, Y and Z *do* affect quality (and of course, try to come up with how we define quality - for example, StanD and I have very different views there).

 

Nelson Pass actually has a very good article on the Pass Labs website, linking perception to science when it comes to amp design, btw.   A step in the right direction, IMO,

I'll bet you that neither of us would like amps that have flaws or sound bad to decent ears.

post #62 of 98
Quote:
Originally Posted by StanD View Post
 

I'll bet you that neither of us would like amps that have flaws or sound bad to decent ears.

 

Dont disagree.   And dont think I said anything otherwise.    

 

It is just that you are using fidelity to the recorded signal as your reference, I am using fidelity to the live, unamplified sound as mine.     In theory, the 2 should be identical, but they arent.    You are happy with your choice of references, as am I.    

 

The only difference is - I am not putting down your choice by referring to it in somewhat condescending terms  :)

 

Out of curiosity - what music do you listen to?  I am curious as to whether preferred music genre predisposes someone one way or another, in the SET vs SS sound palette.


Edited by vkalia - 1/22/14 at 9:58am
post #63 of 98

Quote:

Originally Posted by vkalia View Post

Nelson Pass actually has a very good article on the Pass Labs website, linking perception to science when it comes to amp design, btw.   A step in the right direction, IMO,

A link please to the Nelson Pass article linking perception to science when it comes to amp design, btw. Not finding it!

post #64 of 98
Quote:
Originally Posted by vkalia View Post
 

 

Dont disagree.   And dont think I said anything otherwise.    

 

It is just that you are using fidelity to the recorded signal as your reference, I am using fidelity to the live, unamplified sound as mine.     In theory, the 2 should be identical, but they arent.    You are happy with your choice of references, as am I.    

 

The only difference is - I am not putting down your choice by referring to it in somewhat condescending terms  :)

 

Out of curiosity - what music do you listen to?  I am curious as to whether preferred music genre predisposes someone one way or another, in the SET vs SS sound palette.

I don't see how "I'll bet you that neither of us would like amps that have flaws or sound bad to decent ears" would be condescending and I hope that you would not interpret it so.

I listen to a wide variety of music, from Baroque, classical, romantic (classical) to Jimi Hendrix and rock, to alternate rock to Jazz, especially fusion. I'm not into much of any C&W or Hip Hop. I don't see how this predisposes me to SS or tubes, IMO that's just a personal preference. If I crank up an electric guitar, gimme tubes, when listening to music I prefer SS. There are many tube amps of low distortion that I would like as well.

post #65 of 98

I think for computer music, like Techno,  I think they call it EDM these days - it'd be a bit silly to go tubes.

post #66 of 98

vkalia

if your online as you appear to be I still would like help in finding that.

 

Nelson Pass actually has a very good article on the Pass Labs website, linking perception to science when it comes to amp design, btw.   A step in the right direction, IMO,

 

 

Also perhaps you could just direct me where my question below has perhaps been answered on these Head-Fi forums but if you could answer my question below I would be very appreciative?

 

Quote:from A Tale of Two Tube Amps - The Woo Audio WA7 and ALO Audio PanAm

Originally Posted by Currawong 

 

My normal gear preference and choice for many years has been solid state. I have held a curiosity, however, in tube-based audio gear and the possibilities and presentation that comes from it. 
Originally Posted by Currawong View Post

 better the soundstage, mids and treble are with some of the tubes 

Quote: from "How to equalize your headphones: advanced tutorial (in progress)"
Originally Posted by Joe Bloggs View Post

 

This methodology is the basis for me claiming victory of the $10 Philips SHE3580 over the $200 Etymotic ER-4P (for ergonomic reasons, and because they now sound equally as good to my ears), so there should be something to it ;)

 

Quote: from "Sennheiser HD 600 Appreciation Thread"

Originally Posted by bbmiller View Post

 

Secondly does the old theory of tubes clipping more gracefully the dynamic high peaks in the music still hold sway? I do not know if relatively low-power headphone amps are subject to power amp theory, but I thought may be they are.

 
Quote:"Sennheiser HD 600 Appreciation Thread"
Originally Posted by StanD View Post
 

EQ can help, isn't that part of what a hearing aid does.

Forget about clipping, that should not be happening, get an amp that has enough headroom. This is easy enough to do nowadays. The old theory is not old theory but soft tube clipping is for an electric guitarist not for someone trying to enjoy listening to music (playback). If you opt to buy a tube amp it's not for the purposes of clipping but for the sound of tubes, being even order harmonic distortion, not a lot of it, just a bit for warmth. Myself, I prefer the clean sound of Solid State, but that's a personal choice. I do have a small hybrid amp.

 

 

OK all those preliminary quotes are in preparation to ask you what is the theory of tube rolling is it just the even order harmonic distortion which StanD mentioned in my quote immediately above? Or is it also monkeying around with the total headphones frequency response delivered to your is? (Which I know can also affect soundstage.) Or is it some sort of coloration which can not be called distortion? Or what all you all think is the reasons tube rolling works?


Edited by bbmiller - 3/4/14 at 10:23am
post #67 of 98

I think one would need a funky tube to mess up the FR of a good amp, which is already very flat. I expect to hear some interesting answers, IMO some might be a bit on the imaginitive side and others right on.

post #68 of 98
Quote:
Originally Posted by StanD View Post
 

I don't see how "I'll bet you that neither of us would like amps that have flaws or sound bad to decent ears" would be condescending and I hope that you would not interpret it so.

 

No, that isnt - I couldnt be ar$ed going back and looking it up (nor is it that important, anyway) but some of your earlier posts had across that way.  Although it is possible that I misinterpreted them as well.   Doesnt matter, anyway.

 

Quote:
Originally Posted by StanD View Post
 

I listen to a wide variety of music, from Baroque, classical, romantic (classical) to Jimi Hendrix and rock, to alternate rock to Jazz, especially fusion. I'm not into much of any C&W or Hip Hop. I don't see how this predisposes me to SS or tubes, IMO that's just a personal preference. If I crank up an electric guitar, gimme tubes, when listening to music I prefer SS. There are many tube amps of low distortion that I would like as well.

 

I was wondering if listening to certain types of genres predispose people towards a certain sound palette.   A lot of my rock/metal friends prefer a much more bass-and-treble heavy sound;  most of my classical music buffs tend to prefer the sound of a SET.    

 

BBMiller - here is the article:

https://passlabs.com/articles/audio-distortion-and-feedback

 

Re your question about tube rolling - well, I have built/listened to a bunch of tube amps, but havent really been much into tube rolling.    I'd guess some of it is b/c different tubes may have different curves, so that a given plate voltage results in a slightly different output FR.    Whether or not this is audible and/or a placebo, I dont have the first-hand experience to say.

post #69 of 98
Quote:
Originally Posted by vkalia View Post
 

 

No, that isnt - I couldnt be ar$ed going back and looking it up (nor is it that important, anyway) but some of your earlier posts had across that way.  Although it is possible that I misinterpreted them as well.   Doesnt matter, anyway.

 

 

I was wondering if listening to certain types of genres predispose people towards a certain sound palette.   A lot of my rock/metal friends prefer a much more bass-and-treble heavy sound;  most of my classical music buffs tend to prefer the sound of a SET.    

 

BBMiller - here is the article:

https://passlabs.com/articles/audio-distortion-and-feedback

 

Re your question about tube rolling - well, I have built/listened to a bunch of tube amps, but havent really been much into tube rolling.    I'd guess some of it is b/c different tubes may have different curves, so that a given plate voltage results in a slightly different output FR.    Whether or not this is audible and/or a placebo, I dont have the first-hand experience to say.

If negative loop feedback is used then a flat FR is most likely, otherwise it's up to the design and components. I would think that a design goal for an amp is as flat an FR as possible. I don't think that plate voltage is going to be a player in this as reactance is the key factor.

What's the T in SET for, when it comes to amps it could be Transformer or Triode or even both in the same circuit.

You might want to take a peek at the below, not sure if this is too technical as it would be for most folks.

http://circuitcellar.com/wp-content/uploads/2012/04/Honeycutt-AXapril2012.pdf

post #70 of 98

^^ Sorry, I should have been more clear. T = triode.    

 

You are correct - not all tube amp designs are zero-feedback, single-ended triode designs.  A slightly differently shaped plate voltage/current curve will affect the perceived response of something like a 2A3 SET design by affecting the voltage swing, especially if we are talking about the output tube (although i dont know if this is going to be audible - i havent looked at plate curves for different manufacturers to see how different tubes vary), but not necessarily for other tube-based designs.    

 

Thanks for that link - it's been a long time since i looked at circuitry (havent built any amps for 15 years now), but i'll sit down and look into it when i have the time.  I do have a pair of NOS 45s I just found a couple of weeks ago, and if Mike from Magnequest is still in business, maybe it is time to dig up that soldering iron as well.

 

I think that from a first principles point of the view, the design goal of an amp should be to re-create the sound of a live event as accurately or pleasingly as possible (yes, pleasingly, with all the uncertainties and person-to-person variances that implies).  Now, I agree that a flat FR curve is the best place to start, barring any evidence indicating something otherwise.    But given a choice between perceived preferences (substantiated by DBT, not just placebo) and pure numbers, I'll choose perceived performance.    This may mean different equipment voices to meet different preferences, and perhaps use of a word other than "hi fi" to account for this design goal - which is fine by me.   There is nothing sacrosanct about "hi fi" if that doesnt float someone's boat.

post #71 of 98
Quote:
Originally Posted by vkalia View Post
 

^^ Sorry, I should have been more clear. T = triode.    

 

You are correct - not all tube amp designs are zero-feedback, single-ended triode designs.  A slightly differently shaped plate voltage/current curve will affect the perceived response of something like a 2A3 SET design by affecting the voltage swing, especially if we are talking about the output tube (although i dont know if this is going to be audible - i havent looked at plate curves for different manufacturers to see how different tubes vary), but not necessarily for other tube-based designs.    

 

Thanks for that link - it's been a long time since i looked at circuitry (havent built any amps for 15 years now), but i'll sit down and look into it when i have the time.  I do have a pair of NOS 45s I just found a couple of weeks ago, and if Mike from Magnequest is still in business, maybe it is time to dig up that soldering iron as well.

 

I think that from a first principles point of the view, the design goal of an amp should be to re-create the sound of a live event as accurately or pleasingly as possible (yes, pleasingly, with all the uncertainties and person-to-person variances that implies).  Now, I agree that a flat FR curve is the best place to start, barring any evidence indicating something otherwise.    But given a choice between perceived preferences (substantiated by DBT, not just placebo) and pure numbers, I'll choose perceived performance.    This may mean different equipment voices to meet different preferences, and perhaps use of a word other than "hi fi" to account for this design goal - which is fine by me.   There is nothing sacrosanct about "hi fi" if that doesnt float someone's boat.

There are perceptions and measurements. The THD measurement doesn't really let us know what the distribution and level of harmonics are going to be, so one cannot draw any preconception as to how that will manifest into a tube sound. If the FR measurement is within a small specified range od dB, unless someone is fibbing us we can assume it's flat. If it's flat how can some people say that the tube sound is warm because the mids are poushed up? Perhaps that's a perception based upon increased even harmonics. Many times IM is spec'd but rarely is TIMD spec's and TIMD can be a nasty thing to hear. Any form of IM is most likely more irritating than THD. I think that we can both agree that perception based upon reality is more satisfying than by placebo.

I'm an EE, but haven't messed with tubes for decades. I had modified many a guitar/bass tube amp. Although I started out with music (Analog Synthesizers, etc) and audio design, most of my pro EE career was solid stated design for instrumentation, A/D and microprocessor stuff. These days I write software for stress testing the too big too fail.

post #72 of 98
Quote:
Originally Posted by lookinaround View Post
 

Alright, any suggestions for a DAC/amp combo for around $200? Unfortunately I really don't have a lot of money to spend :/


The Hifiman EF2A is one. I have absolutely no microphonics even if I touch the tubes(which barely even get warm) while playing music on it and can be used on highly sensitive headphones and IEMS without issue. It doesn't pick up any noise from cell phones, wifi routers, etc. It has a dead silent background and is well shielded, the solid state Magni I owned was noisy in comparison. The dac on the EF2A is just okay but gets the job done.

post #73 of 98
Quote:
Originally Posted by kman1211 View Post
 


The Hifiman EF2A is one. I have absolutely no microphonics even if I touch the tubes(which barely even get warm) while playing music on it and can be used on highly sensitive headphones and IEMS without issue. It doesn't pick up any noise from cell phones, wifi routers, etc. It has a dead silent background and is well shielded, the solid state Magni I owned was noisy in comparison. The dac on the EF2A is just okay but gets the job done.

The EF2A's that I listened to had a noise floor that was easy enough to hear. Does yours have the stock 6J1 tubes?

post #74 of 98
Quote:
Originally Posted by StanD View Post
 

The EF2A's that I listened to had a noise floor that was easy enough to hear. Does yours have the stock 6J1 tubes?


Yes, I tried mine both with stock tubes and nos tubes, no noise issues on either tubes. The EF2A was known to have quality control issues in the past. Mine is a relatively new unit and it could just be a good unit, all I can say is my amp is silent and has no noise.

post #75 of 98
Quote:
Originally Posted by StanD View Post
 

There are perceptions and measurements. The THD measurement doesn't really let us know what the distribution and level of harmonics are going to be, so one cannot draw any preconception as to how that will manifest into a tube sound. If the FR measurement is within a small specified range od dB, unless someone is fibbing us we can assume it's flat. If it's flat how can some people say that the tube sound is warm because the mids are poushed up? Perhaps that's a perception based upon increased even harmonics. Many times IM is spec'd but rarely is TIMD spec's and TIMD can be a nasty thing to hear. Any form of IM is most likely more irritating than THD. I think that we can both agree that perception based upon reality is more satisfying than by placebo.

I'm an EE, but haven't messed with tubes for decades. I had modified many a guitar/bass tube amp. Although I started out with music (Analog Synthesizers, etc) and audio design, most of my pro EE career was solid stated design for instrumentation, A/D and microprocessor stuff. These days I write software for stress testing the too big too fail.

 

Yeah, there is a big disjoint between what people claim they can hear and what they actually do, isnt there?    And also between what they claim and what published specs say - my favorite is the guys who claim that one amp is warmer than another when both are 20-20k @ 0,1%.   Yeah, good luck hearing that.

 

I have to admit, i do not know enough about the science of audio perception to say which measurement/spec corresponds to perception.    I had rebuilt a Dynaco ST-70 with Ned @ Triode Electrics's mod, and it sounded fairly neutral and not at all lush/mid-heavy.   With my 2A3, I did find it more lush - you are right, it could be the harmonics giving it that extra body.  I never measured the FR.

 

I have a Systems Engineering degree, although i've never used it - so know just about enough to be dangerous to myself  :).    I do think that the audio world could do with the removal of a few naked emperors, though.

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