Who Know much more about vaccum tube?

[whitte]

The U-Tube video of the Frenchman making his own tubes is a shear testiment, in my books anyways, of dogged determination !! Most of his electronics tools look home made, very well thought out.
It goes to show you that if we really want to do something bad enough, we can do it and it can be done !!!!

W.W.

[Alex]

wow...nice amp. How long did it take to build? oh yeah...it was about 2 weeks. Here are some more pics of your amp...Hahahahahaaa!!!

I never said the pictures are of my version mate. Being accused of stealing IP ranks pretty high on my hate list. And to finish off, I post pictures of my version. Good luck finding these. Oh, hold on, they are pretty similar! Guess it's a different build of the same design.

[Zero999]

What are all those nice new electrolytic and film capacitors and metal film resistors doing in that valve amplifier?

I thought a lot of the unique valve sound created by old amplifiers was due to shitty old waxed paper or ceramic capacitors and noisy carbon composition resistors? Oh, and I hope you're using a paper conned speaker with a paper surround, none of those newer materials such as silicone rubber, foam or polypropylene, again crappy old speakers contributed to the effect.

Oh and where's the output transformer responsible for lots of the distortion?

[Alex]

I think you are confusing this thread with the audiophoolery thread.

[Zero999]

Yes, I suppose I didn't read your posts properly, it's obviously a headphone amplifier not a power amplifier.

No I haven't confused the threads, it looks like an audiophool design to me as a lower distortion solid state amplifier can be built for a fraction of the cost.

[Alex]

Can't miss chocolate if you haven't tried it.

[Zero999]

I've never tried a turd sandwich before but I think I'll give it a miss.

[PetrosA]

I'm not going to get into the tube vs. arguments Sound is too subjective for that and what one person hears may not be heard by someone else. I know that my 41 year old ears can still hear "teen ringtones" and can still tell the difference between a 128 mp3 and the original, and I can often (not always) hear the difference between the best quality VBR mp3 out of Lame and the CD original, at least on my Grado headphones.  I have heard $60,000 systems that I wouldn't pay $10 for, too. If your ears are still good, you can hear the difference between studio masters at 96kHz and a CD at 44,100 Hz on headphones. With good speakers your body will react to the difference in sound quality in addition to your ears.

I think the difference most people hear between old hi-fi tube amps and new stuff has more to do with the source - many CDs are really crappy sounding compared to the original vinyl. Not because CD is inherently worse sounding (although I can hear the difference) but because the remastering was done by way less competent people than the original mastering. Aside from source, I'll bet it's just low quality equipment that people hear which carries the myths forward...

[FreeThinker]

The U-Tube video of the Frenchman making his own tubes is a shear testiment, in my books anyways, of dogged determination !! Most of his electronics tools look home made, very well thought out.
It goes to show you that if we really want to do something bad enough, we can do it and it can be done !!!!

W.W.

Someone should twitter Chris about this

[Fryguy]

PetrosA is absolutely right about todays CDs - they are 99% cheap made crappy sounding BS !  I can hear the so called "Copy Protection" on the Sony/BMG discs IN MY CAR ! BUZZ TICKER TICKER BUZZ . How sad is that ? (yes - i installed 10000 bucks of sound-quality-competition grade audio equipment in my car - but who cares - i love music . . .)

In my livingroom soundsystem (plain old-school stereo) i use tubes in the CD-player output stage - and i love the sound - there is a great difference between listening with the tubes or listening without them (bypassed) .
Don't ask for specific details - with the tubes it is just "more music" .

I started building a tube preamp/filter unit for my vinyl record player 2 years ago - i haven't finished it yet - but i am going to . . . the external power supply is just half done and the tube circuit needs a little finetuning/debugging . The first tests have been quite impressive so far (yes it already works - and i would take it to the pepsi-challenge with any preamp on the market when it is ready !) 

Tubes may be ancient technology but they are far from obsolete and a good tube circuit is always worth the effort .

[Zero999]

Yes I suppose it's subjective but i prefer my music as distortion free and as natural sounding as possible which is why solid state beats valves every time, spending more in inferior technology just doesn't make any sense to me.

But you're right about the crappy remastering on modern CDs.

[jahonen]

Plain distortion figure (especially THD) is not necessarily very good figure of merit (one might say it is meaningless unless measuring bandwidth is also specified), unless the spectrum of distortion components is also known. Higher harmonics tend to be more annoying even with lower percentage figures. I tend to think that IM distortion is better figure of merit.  Most manufacturers seem to just announce the THD, as it gives lower figures. Even if tube amplifiers have relatively high THD figures, the distortion components tend to be low order. On semiconductors, it tends to be other way around.

This is because open loop gain rolls off relatively early for most solid state amplifiers. It really is this excess gain which is used to reduce the distortion. To have really low distortion amplifier, the open loop gain should stay high up to the bandwidth of the input signal. Just look at the open loop gain figures of just about any modern opamp, like OPA2134. You'll see that the open loop gain starts to roll-off as early as 10 Hz! The difference between closed-loop and open loop gains is the factor which reduces distortion. As it rolls off, higher order harmonics are pronounced.

Then there are also exotic distortions, like DIM (characterized and documented by famous Finnish audio researcher in 70's, Matti Otala). It is claimed that DIM can be heard even if it is below noise floor due to ear function (it can dig signal out of noise due to processing gain). Here is a paper where he describes a measurement method for DIM, and shows some results (TIM was the term then).

Regards,
Janne

[Zero999]

The I OPA2134 has under 0.002% distortion across the audio band including the 2nd and 3rd harmonics and under 0.03% with noise accounted for, which is better than any valve amplifier.

This is academic as distortion under 1% is essentially inaudible, as long as the whole amplifier is better than that there's little point in improving it much more.