Valve amplifiers

Fantastic piece of information Sir! :clapping:

I could never have found such a description in wikipedia. I am rushing there right now to update and correct the pages on value amps.

Please post more of such useful info. Would you also be throwing some lights on how the valves control the water flow and a general theory of hydraulics. ;)

am i missing something here? or am i getting it right ;)
 
There is a growing interest in the medical community on the application of valves to treat heart conditions.

Pacemakers, till recently, were used for regular small current feedbacks to keep heart stimulation in patients with advanced heart valve deteriaoration. The warm operation and reliable output of valve amplifiers is being used to substitute pacemakers. John Hopkins university has completed one year of successful trials of nanotechnology based micro valve amplifiers. When used in place of pacemakers, they have been known to stabilise heart valve functioning, regulating blood pressure within +/1 2 units.
 
when people say they love the sound of valves over transistors, they are speaking from their hearts and not necessarily from their brains. This should be obvious, given that there are no valves in our brains, but there are in our hearts.

regards


A valve amplifier or tube amplifier is a type of electronic amplifier that makes use of vacuum tubes to increase the power and/or amplitude of a signal. They are typically (but not exclusively) used for sound amplification, either in home stereo hi-fi amplifiers or for electric guitar amps, or for radio frequency signals.

Low to medium power valve amplifiers for frequencies below the microwaves were largely replaced by solid state amplifiers during the 1960s and 1970s. Valve amplifiers are used for applications such as guitar amplifiers, satellite transponders such as DirecTV and GPS systems, audiophile stereo amplifiers, military applications (such as target acquisition and radar) and very high power radio and UHF television transmitters.
 
There is a growing interest in the medical community on the application of valves to treat heart conditions.

Pacemakers, till recently, were used for regular small current feedbacks to keep heart stimulation in patients with advanced heart valve deteriaoration. The warm operation and reliable output of valve amplifiers is being used to substitute pacemakers. John Hopkins university has completed one year of successful trials of nanotechnology based micro valve amplifiers. When used in place of pacemakers, they have been known to stabilise heart valve functioning, regulating blood pressure within +/1 2 units.

are these SET amps or push pull? i'd love a SET based one. would rather die than install a pp one.
 
There is a growing interest in the medical community on the application of valves to treat heart conditions.

Pacemakers, till recently, were used for regular small current feedbacks to keep heart stimulation in patients with advanced heart valve deteriaoration. The warm operation and reliable output of valve amplifiers is being used to substitute pacemakers. John Hopkins university has completed one year of successful trials of nanotechnology based micro valve amplifiers. When used in place of pacemakers, they have been known to stabilise heart valve functioning, regulating blood pressure within +/1 2 units.

Except when bass heavy tracks are played in which case a slightly loose performance is seen from the valves, leading to irregular heart beats:)

Everybody seems to be in on the off key humour thing these days:).
 
There is a growing interest in the medical community on the application of valves to treat heart conditions.

Pacemakers, till recently, were used for regular small current feedbacks to keep heart stimulation in patients with advanced heart valve deteriaoration. The warm operation and reliable output of valve amplifiers is being used to substitute pacemakers. John Hopkins university has completed one year of successful trials of nanotechnology based micro valve amplifiers. When used in place of pacemakers, they have been known to stabilise heart valve functioning, regulating blood pressure within +/1 2 units.
I too heard about that. Amazing how researchers are pushing the frontier each day.

Recently I was reading about how vacuum tubes are helping in medical treatment of severe cases of constipation and gastric condition. Apparently the patients are made to sit (obviously with clothes removed and a certain lower member of the anatomy properly aligned) on a hot 845 power triode.

As reported the results have been very encouraging. Just one session sufficiently treats any stubborn colonic obstipation, reverting the patient to a pattern of smooth and regular waste disposal. A pleasant side effect is the remarkable audiophile noises generate during the treatment session so much so that Chesky Records are planning to capture the subtle notes for distribution in one of the their forthcoming demo CD. Apparently these notes demonstrate the attack and soundstage of a music system.

These innovative discoveries are guaranteed to keep the Shuguang tube factory going for several more years.
 
I too heard about that. Amazing how researchers are pushing the frontier each day.

Recently I was reading about how vacuum tubes are helping in medical treatment of severe cases of constipation and gastric condition. Apparently the patients are made to sit (obviously with clothes removed and a certain lower member of the anatomy properly aligned) on a hot 845 power triode.

As reported the results have been very encouraging. Just one session sufficiently treats any stubborn colonic obstipation, reverting the patient to a pattern of smooth and regular waste disposal. A pleasant side effect is the remarkable audiophile noises generate during the treatment session so much so that Chesky Records are planning to capture the subtle notes for distribution in one of the their forthcoming demo CD. Apparently these notes demonstrate the attack and soundstage of a music system.

These innovative discoveries are guaranteed to keep the Shuguang tube factory going for several more years.

:clapping: Shu-gu-ang is so appropriate!
 
I too heard about that. Amazing how researchers are pushing the frontier each day.

Recently I was reading about how vacuum tubes are helping in medical treatment of severe cases of constipation and gastric condition. Apparently the patients are made to sit (obviously with clothes removed and a certain lower member of the anatomy properly aligned) on a hot 845 power triode.
.

I shudder to think about the solution for infertility...especially if it is the KR audio T1610 tube
 
I shudder to think about the solution for infertility...especially if it is the KR audio T1610 tube

Should be good for "enlargement" treatment people get spammed about nowadays though ..

"Make her crazy .. go wild, with our T1610 tube replacement therapy. Satisfaction guranteed!!" :lol:
 
George - I greatly enjoyed this particular post from the link you provided. Made sense to me. Or so I think:)

---------------------

1st and foremost a tube (the triode) is the most linear amplifying device invented by man.

All else follows from that.
A typical SS Amp (order of magnitude figures) will have an open loop gain of 100,000 with a feedback factor of 5,000 giving a closed loop gain of 20.
A typical tube amp will have an open loop gain of 50 with a feedback factor of 2.5 giving a closed loop gain of 20.

I'm talking about a combination of local and global feedback here.

Any feedback signal is time delayed and smears time coherency. The more stages the feedback is applied over the worse that problem.

Tube amps therefore tend to sound more "correct" in terms of pace rhythm and attack, they are just (for want of a better adjective) more fluid and "breathe" with the music.

This tends to influence things like stereo imaging or "sound stage" and ambience.

Higher amounts of feedback tend to counter soft compression effects and make clipping harder and more abrupt. In engineering terms we say the transfer function graph (signal voltage out vs signal voltage in) is less smooth with more abrupt corners near the limits. The more abrupt a change in the transfer function the more higher order harmonics are generated. Anyone who has studied musical theory will know that the second harmonic of (for example) a C note is a C one octave above and 3rd harmonic is still musically related BUT by the time you get to 7th, 9th , 11th harmonic the "note" produced is musically unrelated to the fundamental, we call this musically "quint". While 1% 2nd harmonic distortion is "euphonic", about 0.01% of 7th harmonic is seriously objectionable and just grates like fingernails on the blackboard.

The more feedback, the more harmonic multiplication, that is the harmonic distortion products which are in the feedback signal are subject to further harmonic distortions which are then fed back to produce even more.

There are other things at work as well BUT I believe that the level of feedback is the major difference in the sound between SS and tube amps and that teh time coherency is at least or more important than the harmonic distortion profiles.

I design tube amps with local feedback around each tube stage, seldom over 2 or more stages, never over 3 or more stages, and in particular don't use "global" (from output back to input stage) feedback at all.

Just one mans opinion, but an opinion based upon designing and building both SS and tube amps over many years (I've given up the SS Amps now).

Does that mean I don't use SS at all - NO, my tube amp designs use transistor current sources in the "tail" of triode tube differential amplifiers on the input, I often use MOSFET Source Followers with transistor current source loads to drive the output tubes etc. BUT all of the gain stages are tubes. Also I borrow ideas from modern SS amp design to implement things like balanced shunt feedback loops (local feedback around only 2 stages).
-------------------------
 
Get the Wharfedale EVO 4.2 3-Way Standmount Speakers at a Special Offer Price.
Back
Top