Thoughts on tubed preamps?

[Haider]

I got an Aiyima Tube-A3 changed the input and output coupling caps to two 4.7uF , to get bass coming in and out; otherwise bass was being filtered off by the input coupling caps as they were 1uF each (there were two). I then pulled out the op-amps so that it became tube based buffer (current) amplifier. I also got some different makes of tubes, they all sound different, some work better with vocal, others acoustic, rock/pop etc... Recently I have put Burson V6 classic op-amp on the tone controls so that I use my iPhone as a Amazon HD streamer/local storage player via the Lightening to USB3 connector. Peace/Equaliser APO aren't iOS compatible. I use HiFiMan Sundara which need equalising, as do most headphones. A3 complements my Arcam rHead very well...

 

[Haider]

Just to add that there's no reason why a valve-based preamp should be sonically any different to a SS pre-amp, so except for the 'cool' factor mentioned, why bother with the added hassle. If the tubed preamp does sound different, then it's an effects box, and then entirely down to what YOU like, not what's any good.

There are lots of reasons why it's hard for a valve-based power amplifier to be transparent, a few are but not many, but there's no reason why a valved preamp should be any different to a SS one.

S.

There's no reason to say it will sound the same

 

[SIY]

I got an Aiyima Tube-A3 changed the input and output coupling caps to two 4.7uF , to get bass coming in and out; otherwise bass was being filtered off by the input coupling caps as they were 1uF each (there were two).

What was the f3? The size of the input caps is not in and of itself important, it's the time constant.

I also got some different makes of tubes, they all sound different, some work better with vocal, others acoustic, rock/pop etc...

That is beyond dubious. Can we assume that basic controls were not used used in evaluation?

 

[Haider]

Here is a convincing example. Even though speakers are thought to sound different enough to not need blind tests, they absolutely do. See: http://seanolive.blogspot.com/2009/04/dishonesty-of-sighted-audio-product.html

View attachment 23374
I can write an entire book on unreliability of sighted testing including many examples of my own in my job, not hobby. There is no more sold truth in audio than this. Don't doubt it lightly.

Surely then all audio equipment should tested sighted as we all listen to equipment sighted. People can get cured by the placebo effect. We are not organic measuring devices, the human brain, psyche, conscious & sub-conscious play a bigger part than people give them credit for...

 

[SIY]

Surely then all audio equipment should tested sighted as we all listen to equipment sighted. People can get cured by the placebo effect. We are not organic measuring devices, the human brain, psyche, conscious & sub-conscious play a bigger part than people give them credit for...

Science is about determining truth. If you prefer a world of fantasy, perhaps posting in a science-based forum may not be your best bet for satisfaction.

 

[Haider]

What was the f3? The size of the input caps is not in and of itself important, it's the time constant.

That is beyond dubious. Can we assume that basic controls were not used used in evaluation?

Good god man, of course, I switched it on, turned up the volume put some Noel Coward on, whilst wearing my favourite smoking jacket, pipe and scotch in hand...

 

[DonR]

Surely then all audio equipment should tested sighted as we all listen to equipment sighted. People can get cured by the placebo effect. We are not organic measuring devices, the human brain, psyche, conscious & sub-conscious play a bigger part than people give them credit for...

Not true. Biases, especially those involving visual cues, can be very difficult if not impossible to get rid of.

 

[DVDdoug]

I also got some different makes of tubes, they all sound different, some work better with vocal, others acoustic, rock/pop etc...

IMO - That's an indication of a BAD DESIGN.

A hi-fi amplifier is SUPPOSED to be "a straight wire with gain" with no sound characteristics of it's own (except for tone controls, etc.). And, you don't want the sound changing unpredictably as the tubes age, or when they eventually have to be replaced. And you don't want every amp coming off the assembly line to have a different sound.

Transistors and MOSFETs vary too.... Just like with tubes there are specifications and tolerance so the circuit has to be designed to accommodate a range of gains & frequency characteristics, etc. with the amplifier performance staying consistent.

 

[Haider]

Science is about determining truth. If you prefer a world of fantasy, perhaps posting in a science-based forum may not be your best bet for satisfaction.

Science is about getting grants from Industry & government for research and getting your ego stroked. Science is a money making endeavour, just look at the green or the anti-green lobby. You produce the results, facts, figures & stats that the people who paying for it want...

 

[SIY]

Science is about getting grants from Industry & government for research and getting your ego stroked. Science is a money making endeavour, just look at the green or the anti-green lobby. You produce the results, facts, figures & stats that the people who paying for it want...

Uh huh.

 

[Haider]

IMO - That's an indication of a BAD DESIGN.

A hi-fi amplifier is SUPPOSED to be "a straight wire with gain" with no sound characteristics of it's own (except for tone controls, etc.). And, you don't want the sound changing unpredictably as the tubes age, or when they eventually have to be replaced. And you don't want every amp coming off the assembly line to have a different sound.

Transistors and MOSFETs vary too.... Just like with tubes there are specifications and tolerance so the circuit has to be designed to accommodate a range of gains & frequency characteristics, etc. with the amplifier performance staying consistent.

Straight wire with gain is about as likely as water turning into wine.
Rooms are the biggest effects box you can get. Soon as you stick your wire with gain in room all that is gone out of the window.
Go to the Brixton Academy then go listen to a concert in the Hammersmith Apollo, each venue produces a different sound signature...

 

[Haider]

Uh huh.

Do you think the cell-phone industry are going to commission research to prove that cell phone microwaves are harmful to human health. Scientist are bought and paid for. They take the money, they got to come up with the goods...Anyway getting off topic...

 

[SIY]

Do you think the cell-phone industry are going to commission research to prove that cell phone microwaves are harmful to human health. Scientist are bought and paid for. They take the money, they got to come up with the goods...Anyway getting off topic...

Uh huh.

 

[Haider]

Not true. Biases, especially those involving visual cues, can be very difficult if not impossible to get rid of.

Yes, but if it makes you feel the music sounds better then it's done it job. We feel, we don't hear. Our brain/psyche does it's own processing. Hifi A is true to source but HiFi B is not as true to source as A but you think it sounds more enjoyable. What would you rather buy?

 

[ahofer]

Surely then all audio equipment should tested sighted as we all listen to equipment sighted. People can get cured by the placebo effect. We are not organic measuring devices, the human brain, psyche, conscious & sub-conscious play a bigger part than people give them credit for...

That assumes that your sighted bias is stable. Given all the high end audio-treadmilling going on, I don't think that's a very likely claim either. I work with the assumption that the bias I bring from many factors (what I've read, what I know about my equipment, what I've eaten, how my day went..) is "non-stationary". I believe there is a pretty solid body of psycho-acoustic research that suggests the same. After all, people famously hear signal differences after a solid switch 'thunk' even when the switch isn't in the signal or power circuit.

 

[DonR]

Yes, but if it makes you feel the music sounds better then it's done it job. We feel, we don't hear. Our brain/psyche does it's own processing. Hifi A is true to source but HiFi B is not as true to source as A but you think it sounds more enjoyable. What would you rather buy?

Emotions are ephemeral so what I like now might be different from tomorrow.

 

[antcollinet]

Yes, but if it makes you feel the music sounds better then it's done it job. We feel, we don't hear. Our brain/psyche does it's own processing. Hifi A is true to source but HiFi B is not as true to source as A but you think it sounds more enjoyable. What would you rather buy?

Right - which is why as *individuals* we listen. But if we do uncontrolled listening, then what we hear is (should be) of no interest to anyone else because it says nothing about what *they* will hear.

So don't do uncontrolled listening, then come here is try to speak "truths" about how some piece of kit (or a tube) sounds. You'll be gently (the first time**) escorted off stage.


** the second time there might be some chortling. The third time most will have lined up their popcorn.

 

[CanisDirus]

Take it for what it is worth...

I have used a Sony Uda-1 integrated preamp/amp/headphone for 15 years now...got it for free so...why not.
It doesn't measure well when I checked a few months ago...so decided it was time to make some changes.

So...on a whim...I bought a cheap little Aiyima T8 single tube preamp.

All I can say is...there was an immediate difference...same track...same setup...same controls...volume (pre at 99).
You get used to your gear...I never thought the Sony was 'thin'. But when the tube kicked in...it went to a deeper edge.

It was just better.

My wife is very non plussed by it all...she likes music but...gear...big meh.
Even she grudgingly commented that it sounded more full...that's not a blind test...it's a negative test.

The Sony is gone now...but not forgotten. Back in it's box...sleeping.
I'm playing around with hybrid tubepreamp/SSamp for kicks. It's just fun.

 

[DonR]

Take it for what it is worth...

I have used a Sony Uda-1 integrated preamp/amp/headphone for 15 years now...got it for free so...why not.
It doesn't measure well when I checked a few months ago...so decided it was time to make some changes.

So...on a whim...I bought a cheap little Aiyima T8 single tube preamp.

All I can say is...there was an immediate difference...same track...same setup...same controls...volume (pre at 99).
You get used to your gear...I never thought the Sony was 'thin'. But when the tube kicked in...it went to a deeper edge.

It was just better.

My wife is very non plussed by it all...she likes music but...gear...big meh.
Even she grudgingly commented that it sounded more full...that's not a blind test...it's a negative test.

The Sony is gone now...but not forgotten. Back in it's box...sleeping.
I'm playing around with hybrid tubepreamp/SSamp for kicks. It's just fun.

That is not uncommon for tube gear. It adds a fair amount of distortion if designed to do so, which makes the sound "fuller". Small wonder guitarists love tube head amps. Your Sony wasn't thin but accurate. You can get the same effect with a tube buffer.

 

[ahofer]

volume (pre at 99).

that isn't level-matching, unless I misunderstand you. and what @DonR said.