Tube (valve) amp really works!

Some time back I posted a question or two about this tube headphone
amp: http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built
the thing and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on
my desk until a couple weeks ago when I happened to read about another
tube amp and how the amp was left on by the reviewer to break in the
tubes. This made sense to me because tubes do eventually wear out so
some sort of physical change must be happening inside the things. So I
powered up the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more
difference that I can hear.
Eric

 

[Jim Thompson]

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone
amp: http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built
the thing and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on
my desk until a couple weeks ago when I happened to read about another
tube amp and how the amp was left on by the reviewer to break in the
tubes. This made sense to me because tubes do eventually wear out so
some sort of physical change must be happening inside the things. So I
powered up the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more
difference that I can hear.
Eric

For small signals, tubes can be quite linear and low distortion,
particularly if they employ local feedback.

However, if you want "color", why don't you make a comparator part of
your signal path ?>:-}

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

There is no fool quite like an audiphool.

 

On Fri, 16 Dec 2016 13:53:10 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone
amp: http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built
the thing and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on
my desk until a couple weeks ago when I happened to read about another
tube amp and how the amp was left on by the reviewer to break in the
tubes. This made sense to me because tubes do eventually wear out so
some sort of physical change must be happening inside the things. So I
powered up the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more
difference that I can hear.
Eric

For small signals, tubes can be quite linear and low distortion,
particularly if they employ local feedback.

However, if you want "color", why don't you make a comparator part of
your signal path ?>:-}

...Jim Thompson

I dunno. I was just curious about that "tube" sound. I guess if I want
that "comparator" sound I can do as you suggest.
Eric

 

[Tim Wescott]

On Fri, 16 Dec 2016 13:53:10 -0700, Jim Thompson wrote:

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone amp:
http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built the thing
and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on my
desk until a couple weeks ago when I happened to read about another tube
amp and how the amp was left on by the reviewer to break in the tubes.
This made sense to me because tubes do eventually wear out so some sort
of physical change must be happening inside the things. So I powered up
the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more difference
that I can hear.
Eric

For small signals, tubes can be quite linear and low distortion,
particularly if they employ local feedback.

However, if you want "color", why don't you make a comparator part of
your signal path ?>:-}

...Jim Thompson

Yup. Google "fuzzbox". Google "fuzzbox" and "germanium" and be prepared
for a whole different sort of audiophoolery.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

I'm looking for work -- see my website!

 

[Jim Thompson]

On Fri, 16 Dec 2016 15:54:22 -0600, Tim Wescott
<seemywebsite@myfooter.really> wrote:

On Fri, 16 Dec 2016 13:53:10 -0700, Jim Thompson wrote:

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone amp:
http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built the thing
and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on my
desk until a couple weeks ago when I happened to read about another tube
amp and how the amp was left on by the reviewer to break in the tubes.
This made sense to me because tubes do eventually wear out so some sort
of physical change must be happening inside the things. So I powered up
the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more difference
that I can hear.
Eric

For small signals, tubes can be quite linear and low distortion,
particularly if they employ local feedback.

However, if you want "color", why don't you make a comparator part of
your signal path ?>:-}

...Jim Thompson

Yup. Google "fuzzbox". Google "fuzzbox" and "germanium" and be prepared
for a whole different sort of audiophoolery.

As a youngster I played Clarinet in orchestra... thus I prefer a true
"live" sound... perhaps biased by my love of classical music.

But I also like Willie Nelson, the Beatles, Pink Floyd, Chuck Berry,
Big Bopper, Buddy Holly, the Platters, Fats Domino, Ritchie Valens,
Everly Brothers, British marching bands, Sousa, Johnny Cash, Merle
Haggard, Waylon Jennings, Patsy Cline, Kenny Rogers, and, of course,
Elvis... even some favorites from the Middle Ages... Gregorian Chants
;-)

(I have a 300 CD jukebox ;-)

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

 

[Jim Thompson]

On Fri, 16 Dec 2016 16:28:23 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 16 Dec 2016 15:54:22 -0600, Tim Wescott
seemywebsite@myfooter.really> wrote:

[snip]

Yup. Google "fuzzbox". Google "fuzzbox" and "germanium" and be prepared
for a whole different sort of audiophoolery.

As a youngster I played Clarinet in orchestra... thus I prefer a true
"live" sound... perhaps biased by my love of classical music.

But I also like Willie Nelson, the Beatles, Pink Floyd, Chuck Berry,
Big Bopper, Buddy Holly, the Platters, Fats Domino, Ritchie Valens,
Everly Brothers, British marching bands, Sousa, Johnny Cash, Merle
Haggard, Waylon Jennings, Patsy Cline, Kenny Rogers, and, of course,
Elvis... even some favorites from the Middle Ages... Gregorian Chants
;-)

(I have a 300 CD jukebox ;-)

...Jim Thompson

Sheeeesh! I missed Bill Haley, Little Richard, Jerry Lee Lewis & Bo
Diddley ;-)

...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| STV, Queen Creek, AZ 85142 Skype: skypeanalog | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

 

On Fri, 16 Dec 2016 16:32:34 -0700, Jim Thompson
<To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 16 Dec 2016 16:28:23 -0700, Jim Thompson
To-Email-Use-The-Envelope-Icon@On-My-Web-Site.com> wrote:

On Fri, 16 Dec 2016 15:54:22 -0600, Tim Wescott
seemywebsite@myfooter.really> wrote:

[snip]


Yup. Google "fuzzbox". Google "fuzzbox" and "germanium" and be prepared
for a whole different sort of audiophoolery.

As a youngster I played Clarinet in orchestra... thus I prefer a true
"live" sound... perhaps biased by my love of classical music.

But I also like Willie Nelson, the Beatles, Pink Floyd, Chuck Berry,
Big Bopper, Buddy Holly, the Platters, Fats Domino, Ritchie Valens,
Everly Brothers, British marching bands, Sousa, Johnny Cash, Merle
Haggard, Waylon Jennings, Patsy Cline, Kenny Rogers, and, of course,
Elvis... even some favorites from the Middle Ages... Gregorian Chants
;-)

(I have a 300 CD jukebox ;-)

...Jim Thompson

Sheeeesh! I missed Bill Haley, Little Richard, Jerry Lee Lewis & Bo
Diddley ;-)

...Jim Thompson

I really enjoy listening to all sorts of music and feel really lucky
to be able to do so. It seems that some of the older jazz sounds
better after going through the little tube amp. I think this is
because when I first heard it it was from tube audio equipment.
Eric

 

>"I think this is
because when I first heard it it was from tube audio equipment.
Eric"

Interesting. Just like some people tend to like the version of a song they heard first (many remakes over the years) others might associate it with a certain tonal quality.

I got into it for a while, and was surprised at how many remakes are out there. Finding out that some of the 1960s music I liked was really written in the 1940s, etc.

It would be interesting to check the frequency response of that headphone amp, or at least put a 1,000 Hz square wave through it. Even more interesting would be a schematic so we could figure out why there was such a noticeable difference after your burn in.

 

[John Larkin]

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone
amp: http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built
the thing and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on
my desk until a couple weeks ago when I happened to read about another
tube amp and how the amp was left on by the reviewer to break in the
tubes. This made sense to me because tubes do eventually wear out so
some sort of physical change must be happening inside the things. So I
powered up the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more
difference that I can hear.
Eric

Tube burn-in is probably a psychological effect, not a physical one.

Tube sound, ditto.

The sound engineers who make the files and CDs already have a zillion
options to add distortion, tweak frequency response, mix signals, add
noise and echoes and other DSP effects, and they put a lot of time and
money into making things sound "right." Why would running their signal
through a dumb tube amp make it sound better?


--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

On Sat, 17 Dec 2016 10:10:03 -0800, John Larkin
<jjlarkin@highlandtechnology.com> wrote:

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone
amp: http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built
the thing and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on
my desk until a couple weeks ago when I happened to read about another
tube amp and how the amp was left on by the reviewer to break in the
tubes. This made sense to me because tubes do eventually wear out so
some sort of physical change must be happening inside the things. So I
powered up the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more
difference that I can hear.
Eric

Tube burn-in is probably a psychological effect, not a physical one.

Tube sound, ditto.

The sound engineers who make the files and CDs already have a zillion
options to add distortion, tweak frequency response, mix signals, add
noise and echoes and other DSP effects, and they put a lot of time and
money into making things sound "right." Why would running their signal
through a dumb tube amp make it sound better?

Not better, different. Like adding different spices to food. I think
lots of pepper makes my eggs taste better. My wife thinks eggs with
lots of pepper taste worse. But really all the pepper does to the
taste is make it taste different. But of course you know all that.
Eric

 

On Sat, 17 Dec 2016 02:46:03 -0800 (PST), jurb6006@gmail.com wrote:

"I think this is
because when I first heard it it was from tube audio equipment.
Eric"

Interesting. Just like some people tend to like the version of a song they heard first (many remakes over the years) others might associate it with a certain tonal quality.

I got into it for a while, and was surprised at how many remakes are out there. Finding out that some of the 1960s music I liked was really written in the 1940s, etc.

It would be interesting to check the frequency response of that headphone amp, or at least put a 1,000 Hz square wave through it. Even more interesting would be a schematic so we could figure out why there was such a noticeable difference after your burn in.

Go to this link: http://oatleyelectronics.com/files/K272X.pdf
to see the schematic. Another thing that happened after burn in is
that the tubes became (more) microphonic. The kit came with rubber
grommets that the instructions say need to be pushed over the tubes in
order to damp vibrations because the tubes are microphonic. After I
soldered the kit together I tried to make the tubes ring. I tapped the
board softly, then harder, then harder still and finally tapped the
tubes themselves with my fingernail. Nothing. I figured that maybe the
microphonic sound was something my non-audiophile ears just couldn't
hear. That's no the case now. Tapping the tubes with a fingernail
produces a very audible ring. Tapping the circuit board hard enough
produces rings in both channels.
Eric

 

[John Larkin]

On Sat, 17 Dec 2016 10:37:42 -0800, etpm@whidbey.com wrote:

On Sat, 17 Dec 2016 02:46:03 -0800 (PST), jurb6006@gmail.com wrote:

"I think this is
because when I first heard it it was from tube audio equipment.
Eric"

Interesting. Just like some people tend to like the version of a song they heard first (many remakes over the years) others might associate it with a certain tonal quality.

I got into it for a while, and was surprised at how many remakes are out there. Finding out that some of the 1960s music I liked was really written in the 1940s, etc.

It would be interesting to check the frequency response of that headphone amp, or at least put a 1,000 Hz square wave through it. Even more interesting would be a schematic so we could figure out why there was such a noticeable difference after your burn in.
Go to this link: http://oatleyelectronics.com/files/K272X.pdf
to see the schematic.

That is hilarious in so many ways!



Another thing that happened after burn in is

that the tubes became (more) microphonic. The kit came with rubber
grommets that the instructions say need to be pushed over the tubes in
order to damp vibrations because the tubes are microphonic. After I
soldered the kit together I tried to make the tubes ring. I tapped the
board softly, then harder, then harder still and finally tapped the
tubes themselves with my fingernail. Nothing. I figured that maybe the
microphonic sound was something my non-audiophile ears just couldn't
hear. That's no the case now. Tapping the tubes with a fingernail
produces a very audible ring. Tapping the circuit board hard enough
produces rings in both channels.

Funny!



>Eric

--

John Larkin Highland Technology, Inc

lunatic fringe electronics

 

[asdf]

On Fri, 16 Dec 2016 12:42:10 -0800, etpm wrote:

Anyway, I built the thing and while it did amplify it did not seem to
color the sound despite the good reviews about the thing I found online.

If it colored the sound it wouldn't be HiFi and would not deserve
good reviews anywhere. Stay away from any place where they consider
altering the sound a good thing in a HiFi device; it's the usual
trap to sell you something overpriced to reach that "color".
That trick would not work if you got a flat amplifier and were
satisfied about it. Flat is flat, so no reason to waste any more
money, but there are many kinds of sound "coloration".
Got the trick?

 

[default]

On Sat, 17 Dec 2016 10:10:03 -0800, John Larkin wrote:

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone amp:
http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built the thing
and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on my
desk until a couple weeks ago when I happened to read about another tube
amp and how the amp was left on by the reviewer to break in the tubes.
This made sense to me because tubes do eventually wear out so some sort
of physical change must be happening inside the things. So I powered up
the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more difference
that I can hear.
Eric

Tube burn-in is probably a psychological effect, not a physical one.

Tube sound, ditto.

The sound engineers who make the files and CDs already have a zillion
options to add distortion, tweak frequency response, mix signals, add
noise and echoes and other DSP effects, and they put a lot of time and
money into making things sound "right." Why would running their signal
through a dumb tube amp make it sound better?

Placebo effect - Nothing sounds as good as the distortion you're used to?

 

On 19 Dec 2016 13:26:19 GMT, default <default@defaulter.net> wrote:

On Sat, 17 Dec 2016 10:10:03 -0800, John Larkin wrote:

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone amp:
http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built the thing
and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on my
desk until a couple weeks ago when I happened to read about another tube
amp and how the amp was left on by the reviewer to break in the tubes.
This made sense to me because tubes do eventually wear out so some sort
of physical change must be happening inside the things. So I powered up
the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more difference
that I can hear.
Eric

Tube burn-in is probably a psychological effect, not a physical one.

Tube sound, ditto.

The sound engineers who make the files and CDs already have a zillion
options to add distortion, tweak frequency response, mix signals, add
noise and echoes and other DSP effects, and they put a lot of time and
money into making things sound "right." Why would running their signal
through a dumb tube amp make it sound better?

Placebo effect - Nothing sounds as good as the distortion you're used to?

Which is not the placebo effect. The placebo effect is expecting
something to happen and it you think it does even though nothing has
changed to cause that something to happen. If I expect the music to
sound better and there is no change to the sound but I think it now
sounds better then that is the placebo effect.

 

[Tim Wescott]

On Mon, 19 Dec 2016 09:30:36 -0800, etpm wrote:

On 19 Dec 2016 13:26:19 GMT, default <default@defaulter.net> wrote:

On Sat, 17 Dec 2016 10:10:03 -0800, John Larkin wrote:

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone
amp:
http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built the
thing and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on
my desk until a couple weeks ago when I happened to read about another
tube amp and how the amp was left on by the reviewer to break in the
tubes. This made sense to me because tubes do eventually wear out so
some sort of physical change must be happening inside the things. So I
powered up the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more
difference that I can hear.
Eric

Tube burn-in is probably a psychological effect, not a physical one.

Tube sound, ditto.

The sound engineers who make the files and CDs already have a zillion
options to add distortion, tweak frequency response, mix signals, add
noise and echoes and other DSP effects, and they put a lot of time and
money into making things sound "right." Why would running their signal
through a dumb tube amp make it sound better?

Placebo effect - Nothing sounds as good as the distortion you're used
to?
Which is not the placebo effect. The placebo effect is expecting
something to happen and it you think it does even though nothing has
changed to cause that something to happen. If I expect the music to
sound better and there is no change to the sound but I think it now
sounds better then that is the placebo effect.

Yup. Which is why the really high-end audio reviews always start by
listing the price of the component as if it were a Good Thing. 'cuz if
it costs a lot, it has to sound good.

--
Tim Wescott
Control systems, embedded software and circuit design
I'm looking for work! See my website if you're interested
http://www.wescottdesign.com

 

[Tim Wescott]

On Sat, 17 Dec 2016 10:10:03 -0800, John Larkin wrote:

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone amp:
http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built the thing
and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on my
desk until a couple weeks ago when I happened to read about another tube
amp and how the amp was left on by the reviewer to break in the tubes.
This made sense to me because tubes do eventually wear out so some sort
of physical change must be happening inside the things. So I powered up
the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more difference
that I can hear.
Eric

Tube burn-in is probably a psychological effect, not a physical one.

Either that or he's knocked the edge off of the batteries' charge, and
the thing distorts more at a lower plate voltage and/or higher source
resistance in the 'B' battery.

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

I'm looking for work -- see my website!

 

[John Larkin]

On 19 Dec 2016 13:26:19 GMT, default <default@defaulter.net> wrote:

On Sat, 17 Dec 2016 10:10:03 -0800, John Larkin wrote:

On Fri, 16 Dec 2016 12:42:10 -0800, etpm@whidbey.com wrote:

Some time back I posted a question or two about this tube headphone amp:
http://oatleyelectronics.com/files/K272X.pdf . Anyway, I built the thing
and while it did amplify it did not seem to color the sound,
despite the good reviews about the thing I found online. So it sat on my
desk until a couple weeks ago when I happened to read about another tube
amp and how the amp was left on by the reviewer to break in the tubes.
This made sense to me because tubes do eventually wear out so some sort
of physical change must be happening inside the things. So I powered up
the little headphone amp and left it on for about 28 hours.
I then tried it out with some good earbuds and as a pre-amp for my
Pioneer SX-434. It now changes the sound. Not as much as I expected,
but maybe it's not supposed to. For some music I like using it better
than just plugging my digital sound source into the Pioneer. I suspect
that when I get some good headphones there will be even more difference
that I can hear.
Eric

Tube burn-in is probably a psychological effect, not a physical one.

Tube sound, ditto.

The sound engineers who make the files and CDs already have a zillion
options to add distortion, tweak frequency response, mix signals, add
noise and echoes and other DSP effects, and they put a lot of time and
money into making things sound "right." Why would running their signal
through a dumb tube amp make it sound better?

Placebo effect - Nothing sounds as good as the distortion you're used to?

Double-blind testing makes a lot of acoustic effects disappear.


--

John Larkin Highland Technology, Inc
picosecond timing precision measurement

jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com

 

>"When asked by jurb for a
schematic I provided a link and you found that laughable for more than
one reason. How about, since this is an electronics basics group,
letting me know what was so laughable? "

The damn thing wouldn't open for me.

 

Is this it ?

http://diyaudioprojects.com/Tubes/6418-Tube-Preamp-Headphone-Kit/

If that is it, I see no reason for it. you got OP AMPs on the end of triodes, if the OP AMPs can deliver the nuances of the sound from triodes they should be able to do it by themselves.

Of course it is a pentode, but wired as a triode. And the way it is showing it is a directly heated cathode which means one channel has bias and the other does not.

What you are probably hearing is an anomoly due to the input coupling cap charging to make for some badly needed negative bias. I have seen other amps like this and when I see them I think Madman Muntz. If what I found there is actually the print for it, I would never buy it.

These no bias people can sit there and say all day that "The audio biases it", sure does, now when it comes down to half the conduction where you should have biased it in the first place it shifts DC level on the output. I could design better than that at fifteen years old. If I am looking at the right thing of course.

The thing here is cheap. Sure, use a DC filament supply, but if a directly heated cathode you don't put them in series. You need that positive voltage, and in STEREO, remember there are two identical channels, you need the same bias on each channel. Not for one to be biased by the power supply and the other to be self biased like the horizontal output in an old TV set.

Not not be mean, but if the link I put up is of that thing, it is not high fidelity, it is not worth shit by any metric. If you like it then that is because you like a certain type of distortion, because that has it Man. No bias ?

Probably designed by a millenial.

That is my opinion. It affects nothing else.

I believe they got you fooled because of that grid current biasing system. It probably makes the soundstage sound a bit different because of the delay in output of one of the channels. The other channel has bias.

I have seen shit like this before.