Best cheap Valve Amp for retro stereogram?

[Lignum]

Im making a retro 40`s style stereogram and want to include a valve amp mainly for the “visuals” I want the valves to be visible, so looks are more important than pure sound quality. So far I have found the Hybrid valve amp (http://www.jaycar.com.au/productView.asp?ID=AA0474&CATID=15&form=CAT&SUBCATID=443) from Jcar for $200 anyone know if it is ok or crap (considering its cheap price) and is their an alternative like a Chinese one .:)

[GraemeCook]

Hi Lignum

Audio stores routinely trade-in old stereo gear. Some valve amplifiers are regarded as classics and have "collectors" prices but most get onsold, either as-traded or fully-serviced, for very affordable prices and the sound quality can be outstanding, except for deep bass.

Another source is auctions, but buyer beware, and any restoration can be expensive.

Finally I have heard some good reports on chinese amplifiers, but have no first hand experience.

Cheers

Graeme

[Zaphod]

Im making a retro 40`s style stereogram and want to include a valve amp mainly for the “visuals” I want the valves to be visible, so looks are more important than pure sound quality. So far I have found the Hybrid valve amp (http://www.jaycar.com.au/productView.asp?ID=AA0474&CATID=15&form=CAT&SUBCATID=443)from Jcar for $200 anyone know if it is ok or crap (considering its cheap price) and is their an alternative like a Chinese one .:)

The Jaycar amp is a POS. The valves do almost nothing. The amplifier, itself, is a basic IC output stage affair. The valves are there mostly for looks. Not quite. The valves actually do some amplification and this makes the thing a big problem. it would be better if the valves did nothing. The reason it is such a problem, is because the valves are operated at an excessively high heater Voltage, they will not last long. When they fail, the amp will cease operation. If you like the looks, then buy it. Be aware that there is a good reason it is so cheap. It is crap.

Alternatively, you could buy a cheap amplifier and some valves you like the look of (there are some mighty pretty ones available) and connect the heaters of the valves to an appropriate power source, so they light up. Plonk the valves on an appropriate chassis and you'll have decent sound, without the unreliability.

[TP1]

Now this is one area I have had a lot of experience with. It depends what you want., Personally i wouldn't buy the jacar one, but I would buy a Chinese made alternative. As luck would have it, The Chinese make some superb sounding gear that is badge engineered around the world for many times the price.

Make no mistake, the cheapish Chinese amps available on the internet from decent "Name" Chinese companies are superb in both looks and sound. Another thing, don't be alarmed at the low wattage output of valve amplifiers - they operate in Class A mode and all have high current ability which will easily outperform solid state amps of the same wattage.

For a cheap but true Hi-Fi amp look at something like:

http://www.ornec.com/Meixing_MingDa_MC-34A_QQC100038

[Zaphod]

Now this is one area I have had a lot of experience with. It depends what you want., Personally i wouldn't buy the jacar one, but I would buy a Chinese made alternative. As luck would have it, The Chinese make some superb sounding gear that is badge engineered around the world for many times the price.

Make no mistake, the cheapish Chinese amps available on the internet from decent "Name" Chinese companies are superb in both looks and sound. Another thing, don't be alarmed at the low wattage output of valve amplifiers - they operate in Class A mode and all have high current ability which will easily outperform solid state amps of the same wattage.

For a cheap but true Hi-Fi amp look at something like:

http://www.ornec.com/Meixing_MingDa_MC-34A_QQC100038

PUKE! 86dB S/N and 8% THD. What a piece of crap! The distortion level, alone, is an order of magnitude higher than that of a decent loudspeaker.

Nope. This is an area you DO NOT have a lot of experience with. Very few amplifiers are actually Class A. Cheap Chinese amps are, in the main, crap. They may look pretty, but they almost always use crap output transformers. This will lead to ordinary sound quality. A good output transformer is difficult and very expensive to manufacture, requiring upwards of 13 or more interleaves. Typically, cheap Chinese valve amps use no interleaves. They use a glorified power transformer. Something Western designers have not used in more than 60 years.

Further: Watts is Watts. Class A or otherwise. All things being equal, a 10 Watt Class A amplifier will sound just as loud (or soft) as a 10 Watt Class A/B one.

The term 'Class A' is one of the most misused and most misunderstood terms presently being bandied around. In fact, I always measure any amplifier which is claimed to be Class A, whenever it lands on my bench. 99 times out of 100 (yes, THAT often) the Class A amp is actually a Class A/B one, which runs a little warmer than usual. Here's some measurements I've performed:

Amp W: Claimed Class A - 160 Wats. Actual Class A - 35 Watts.
Amp X: Claimed Class A - 20 Watts. Actual Class A - 1.75 Watts.
Amp Y: Claimed Class A - 185 Watts. Actual Class A - 12 Watts.
Amp Z: Claimed Class A - 30 Watts. Actual Class A - 3 Watts.

Make no mistake: These are all substantial Class A power levels (typical amplifiers operate at around 0.1 Watts Class A) and the amps all run warm. They are not Class A amplifiers. They are Class A/B types. Just like the vast majority of cheap, crappy Chinese ones. And there's is absolutely nothing wrong with a properly designed Class A/B amplifier. Self has shown that the distortion of a Class A/B amplifier is lower than a Class A one.

[TP1]

PUKE! 86dB S/N and 8% THD. What a piece of crap! The distortion level, alone, is an order of magnitude higher than that of a decent loudspeaker.

Nope. This is an area you DO NOT have a lot of experience with. Very few amplifiers are actually Class A. Cheap Chinese amps are, in the main, crap. They may look pretty, but they almost always use crap output transformers. This will lead to ordinary sound quality. A good output transformer is difficult and very expensive to manufacture, requiring upwards of 13 or more interleaves. Typically, cheap Chinese valve amps use no interleaves. They use a glorified power transformer. Something Western designers have not used in more than 60 years.

Further: Watts is Watts. Class A or otherwise. All things being equal, a 10 Watt Class A amplifier will sound just as loud (or soft) as a 10 Watt Class A/B one.

The term 'Class A' is one of the most misused and most misunderstood terms presently being bandied around. In fact, I always measure any amplifier which is claimed to be Class A, whenever it lands on my bench. 99 times out of 100 (yes, THAT often) the Class A amp is actually a Class A/B one, which runs a little warmer than usual. Here's some measurements I've performed:

Amp W: Claimed Class A - 160 Wats. Actual Class A - 35 Watts.
Amp X: Claimed Class A - 20 Watts. Actual Class A - 1.75 Watts.
Amp Y: Claimed Class A - 185 Watts. Actual Class A - 12 Watts.
Amp Z: Claimed Class A - 30 Watts. Actual Class A - 3 Watts.

Make no mistake: These are all substantial Class A power levels (typical amplifiers operate at around 0.1 Watts Class A) and the amps all run warm. They are not Class A amplifiers. They are Class A/B types. Just like the vast majority of cheap, crappy Chinese ones. And there's is absolutely nothing wrong with a properly designed Class A/B amplifier. Self has shown that the distortion of a Class A/B amplifier is lower than a Class A one.

I'm afraid it is you , sir, who is grossly mistaken and without sufficient experience in these matters!
1. "Watts is Watts" is a misinformed concept, Its like saying all engines with the same horsepower are the same. You cannot use a 200 BHP 1.6 litre petrol engine to drive a large truck, But you can use a 200 BHP 6 litre diesel to do it. The difference is the torque, and in the amplifier equivalent is current. Valve amps have way more current handling ability (AMPS) than transistor amps of equivalent wattage.It is a necessity due to the way they operate.
2. Your own measurements confirm that you cannot not rely on wattage claims made for most amps as a basis for comparison

3. Quoting distortion figures in isolation for a valve amp vs solid state as a basis for sound quality comparison has left me wondering whether you have had a chance to listen to modern decent hi-fi valve amps. The distortion produced by valve amplifiers is mostly even order harmonics which enhances a natural sound. Solid state amps produce harsh, odd order harmonics and most of the circuitry used in these amps is to control this phenomenon. Distortion control through the use of comparatively large amounts of negative feedback does reduce distortion significantly, but can also make it sound less natural.

4. Valve amps do not sound harsh when driven into clipping distortion, unlike solid state amps.
The reason the best guitar amplifiers are valve based (always have been, always will be) are because they sound way more natural and musical. Some music is recorded with the amps being deliberately driven into distortion, something that would be way to harsh with transistors.

5. Your comments on class A claims are valid as many manufacturers really only operate with a higher bias current in A/B to reduce the switching distortion. However most valve amps even in push-pull configuration have full current at to all output devices.

6. Transformer types. Now I am referring to valve amps here from reputable Chinese manufacturers when I say I am not familiar with the flimsy transformers. In my main Hifi system I have bi-amped the speakers with 4 identical valve power amps, each weighing 44 Kg. The weight is mostly due to the massive output transformers used.

7. Despite the above, I do think there are excellent solid state gear out there but the thread was started with an enquiry about a nice valve amp for a particular application, hence the discussion

[Zaphod]

I'm afraid it is you , sir, who is grossly mistaken and without sufficient experience in these matters!



Incorrect. Continue.



1. "Watts is Watts" is a misinformed concept, Its like saying all engines with the same horsepower are the same. You cannot use a 200 BHP 1.6 litre petrol engine to drive a large truck, But you can use a 200 BHP 6 litre diesel to do it. The difference is the torque, and in the amplifier equivalent is current. Valve amps have way more current handling ability (AMPS) than transistor amps of equivalent wattage.It is a necessity due to the way they operate.


Incorrect. Valve amplifiers are precisely the WRONG amplifier to use when large currents are required. Valves are an inherently high output impedance devices, whilst transistors are inherently low impedance. Valve amplifiers are further hampered by the output transformer, which introduces more output resistance. A good transistor amplifier can source several tens of Amps. Valve amps cannot hope to manage such a feat. Unless they are truely prodigious and silly beasts.

Note the output impedance of a decent transistor amp:

http://stereophile.com/integratedamps/1006nad/index5.html

Now, note the output impedance of a decent valve amp:

http://stereophile.com/tubepoweramps/807ar/index4.html

Now, note the output impedance of a crappy valve amp:

http://stereophile.com/tubepoweramps/687/index6.html

Note the frequency response variations, due to that output impedance. This is largely what people hear, when listening to crappy valve amplifiers. They like the bad frequency response. It may not be hi fi, but it is what they like. I have no issue with personal preference. I do, however, take issue when people try to pass off crap as hi fi.



2. Your own measurements confirm that you cannot not rely on wattage claims made for most amps as a basis for comparison


Nope. My measurements prove that you cannot rely on a manufacturer's claims re. Class A operation. Usually, the output power rating is a figure that most manufacturers manage to get mostly correct. It is certainly the easiest figure to verify, so manufacturers tend to be relatively honest about it.



3. Quoting distortion figures in isolation for a valve amp vs solid state as a basis for sound quality comparison has left me wondering whether you have had a chance to listen to modern decent hi-fi valve amps.


8% distortion is pitifully horrible. There are many decent valve amps which can easily manage respectable distortion levels. I have no idea what your experience is with valve amps, but I certainly listened to more valve amps than I've had hot breakfasts. Probably in the order of several hundred. Some were good, some were bad. Cheap, Chinese valve amps are almost all bad. Most use output transformers which are not decent audio transformers.



The distortion produced by valve amplifiers is mostly even order harmonics which enhances a natural sound. Solid state amps produce harsh, odd order harmonics and most of the circuitry used in these amps is to control this phenomenon.


Be VERY careful here. This is my area of expertise. You are wrong. Very wrong. The disortion produced by an amplifier is almost TOTALLY dominated by it's topology (the way the devices are used), not the technology (valves or transistors). For instance:

A single ended (SE) amplifier (be it transistors or valves) will exhibit certain amounts of even and odd order harmonic distortion. A push pull (PP) amplifier (be it transistors or valves) will exhibit far less even order distortion and approximately similar levels of odd order distortion. It is the TOPOLOGY (PP or SE) which determines the types of distortion products, not the devices used.



Distortion control through the use of comparatively large amounts of negative feedback does reduce distortion significantly, but can also make it sound less natural.


That depends on the method of feedback. Local feedback is relatively benign, whilst Global NFB can cause problems. Not all feedback is bad. It's just how and where it is applied that matters. Triodes, for instance, use an internal NFB mechanism that Pentodes lack. Most valve afficiondos will agree that Triodes are superior amplification devices to Pentodes.



4. Valve amps do not sound harsh when driven into clipping distortion, unlike solid state amps.



More bollocks. Whilst most transistor amps do clip nastily, it need not be so. Many transistor amplifiers have come to market, which employ various methods of 'soft clipping', that surpass the clipping cahracteristics of many valve amps. In the low end, we have NAD and in the high end, there are the Aussie made ME amplifiers. Both produce very gentle clipping characteristics. At the other end of the scheme lie Audio Research (valve) amplifiers, which clip very harshly indeed. Again, it's all down to the TOPOLOGY, not the devices.



The reason the best guitar amplifiers are valve based (always have been, always will be) are because they sound way more natural and musical.


Bollocks. There are some good valve amps and some crappy valve amps. Just as there are some good transistor amps and some crappy transistor amps. Stating that:

Valve amps = good, transistor amps = bad. Is just plain ignorant.



Some music is recorded with the amps being deliberately driven into distortion, something that would be way to harsh with transistors.


You're behind the times. Modern solid state technology can provide anything that was provided in the past by valves. That includes distortion.



5. Your comments on class A claims are valid as many manufacturers really only operate with a higher bias current in A/B to reduce the switching distortion. However most valve amps even in push-pull configuration have full current at to all output devices.


Nope. They do not.



6. Transformer types. Now I am referring to valve amps here from reputable Chinese manufacturers when I say I am not familiar with the flimsy transformers. In my main Hifi system I have bi-amped the speakers with 4 identical valve power amps, each weighing 44 Kg. The weight is mostly due to the massive output transformers used.


I don't give a crap about the mass. How many interleaves are used in the output transformers? THAT is the only issue of merit. I've examined enough cheap, Chinese amps (and some expensive ones) to realise that far too much money is placed into the cosmetics.



7. Despite the above, I do think there are excellent solid state gear out there but the thread was started with an enquiry about a nice valve amp for a particular application, hence the discussion

Indeed. The best option is to use a cheap transistor amp and fake some valves. Good reliability (which is certainly not possible with the Jaycar crap) and reasonable sound.

[TP1]

Incorrect. Continue.



Incorrect. Valve amplifiers are precisely the WRONG amplifier to use when large currents are required. Valves are an inherently high output impedance devices, whilst transistors are inherently low impedance. Valve amplifiers are further hampered by the output transformer, which introduces more output resistance. A good transistor amplifier can source several tens of Amps. Valve amps cannot hope to manage such a feat. Unless they are truely prodigious and silly beasts.

Note the output impedance of a decent transistor amp:

http://stereophile.com/integratedamps/1006nad/index5.html

Now, note the output impedance of a decent valve amp:

http://stereophile.com/tubepoweramps/807ar/index4.html

Now, note the output impedance of a crappy valve amp:

http://stereophile.com/tubepoweramps/687/index6.html

Note the frequency response variations, due to that output impedance. This is largely what people hear, when listening to crappy valve amplifiers. They like the bad frequency response. It may not be hi fi, but it is what they like. I have no issue with personal preference. I do, however, take issue when people try to pass off crap as hi fi.



Nope. My measurements prove that you cannot rely on a manufacturer's claims re. Class A operation. Usually, the output power rating is a figure that most manufacturers manage to get mostly correct. It is certainly the easiest figure to verify, so manufacturers tend to be relatively honest about it.



8% distortion is pitifully horrible. There are many decent valve amps which can easily manage respectable distortion levels. I have no idea what your experience is with valve amps, but I certainly listened to more valve amps than I've had hot breakfasts. Probably in the order of several hundred. Some were good, some were bad. Cheap, Chinese valve amps are almost all bad. Most use output transformers which are not decent audio transformers.



Be VERY careful here. This is my area of expertise. You are wrong. Very wrong. The disortion produced by an amplifier is almost TOTALLY dominated by it's topology (the way the devices are used), not the technology (valves or transistors). For instance:

A single ended (SE) amplifier (be it transistors or valves) will exhibit certain amounts of even and odd order harmonic distortion. A push pull (PP) amplifier (be it transistors or valves) will exhibit far less even order distortion and approximately similar levels of odd order distortion. It is the TOPOLOGY (PP or SE) which determines the types of distortion products, not the devices used.



That depends on the method of feedback. Local feedback is relatively benign, whilst Global NFB can cause problems. Not all feedback is bad. It's just how and where it is applied that matters. Triodes, for instance, use an internal NFB mechanism that Pentodes lack. Most valve afficiondos will agree that Triodes are superior amplification devices to Pentodes.



More bollocks. Whilst most transistor amps do clip nastily, it need not be so. Many transistor amplifiers have come to market, which employ various methods of 'soft clipping', that surpass the clipping cahracteristics of many valve amps. In the low end, we have NAD and in the high end, there are the Aussie made ME amplifiers. Both produce very gentle clipping characteristics. At the other end of the scheme lie Audio Research (valve) amplifiers, which clip very harshly indeed. Again, it's all down to the TOPOLOGY, not the devices.



Bollocks. There are some good valve amps and some crappy valve amps. Just as there are some good transistor amps and some crappy transistor amps. Stating that:

Valve amps = good, transistor amps = bad. Is just plain ignorant.



You're behind the times. Modern solid state technology can provide anything that was provided in the past by valves. That includes distortion.



Nope. They do not.



I don't give a crap about the mass. How many interleaves are used in the output transformers? THAT is the only issue of merit. I've examined enough cheap, Chinese amps (and some expensive ones) to realise that far too much money is placed into the cosmetics.



Indeed. The best option is to use a cheap transistor amp and fake some valves. Good reliability (which is certainly not possible with the Jaycar crap) and reasonable sound.

I don't think an impartial reader would have interpreted what I had said in the manner that you did. Of course there are good and bad examples of each, DUH!!

You clearly have no experience whatsoever with the quality valve amps to which I am referring to. The point is not how you think the unit performs on paper but how it in fact sounds. The internet is full of transistor vs valve/tube discussions and your uninformed and very rude response is not helpful to anyone, least of all Lignum who asked a perfectly valid question at the start of this thread.

The issue of output impedance is one of speaker matching, but good valve amps have multiple outputs so that speakers with different impedances can be appropriately hooked up.

As to current handling ability, its time for you to stop relying on ancient history and get with the times. Its not that transistor amps can't have the same ability (as you misqouoted me) its that modern valve amps have massive power supplies with high current abilities beyond equivalently priced transitor amps with the same wattage.If you are quoting your understanding based upon your own experiences , then I would suggest that your experiences have been limited in the field of modern quality valve amps.

In any event, it is the sound that is the issue and I began by tring to explain why, say, a 0.2% THD valve amp can sound better than a O.02 % THD solid state amp. The vast majority of musicians around the world who use amps in performances agree. For the record I have variety of both, and each has its place, but remember the question at the beginning of the thread?

This is not the forum to go into the technicalities and experiences in greater detail and we could fill libraries with selective quotes from magazines, but if you are in Perth, I would be happy to show you what I am referring to.

[watson]

:toot:

A point can be made without denigrating other posters.
This is a pleasant place........Lets Keep it that way.

Noel Watson
Administrator

[Zaphod]

I don't think an impartial reader would have interpreted what I had said in the manner that you did. Of course there are good and bad examples of each, DUH!!

You clearly have no experience whatsoever with the quality valve amps to which I am referring to.


I may have no experience with the particular valve amps you own. I have, OTOH, considerable listening and bench experience with the following brands of valve power amps:

Audio Research
Dynaco
EAR
Conrad Johnson
VAC
Manly Labs
McIntosh
Turner Audio
Quad
Baird
VTL
BAT
Cary
Counterpoint

And many others. Some were excellent and some were not. Most of the above brands used output transformers which used a considerable number of interleaves. How many interleaves are used on the output transformers in your amplifiers?



The point is not how you think the unit performs on paper but how it in fact sounds.


The beauty of objective testing, is that it allows us to dispense with products which are clearly faulty. An amplifier which exhibits 8% THD is faulty. It need not be auditioned, because it's distortion is clearly audible.



The internet is full of transistor vs valve/tube discussions and your uninformed and very rude response is not helpful to anyone, least of all Lignum who asked a perfectly valid question at the start of this thread.


Rude? I merely corrected your misconceptions. Nothing more. I am sorry I shattered your illusions about Class A and valve equipment. Them's the facts though.



The issue of output impedance is one of speaker matching, but good valve amps have multiple outputs so that speakers with different impedances can be appropriately hooked up.


Unfortunately, loudspeakers do not represent a purely resistive load. Look at the impedance curve of this speaker:

http://stereophile.com/floorloudspeakers/infinity_irs_epsilon_loudspeaker/index5.html

You'll note that the bass impedance varies from 12 Ohms down to 4 Ohms and the treble varies from as high as 8.5 Ohms, down to less than 3 Ohms. Which tap will you use? It can only be correct for one part of the operating region.

Here's another:

http://stereophile.com/floorloudspeakers/650/index11.html

It varies from a high of 33 Ohms down to 1.6 Ohms! Which tap would you use?



As to current handling ability, its time for you to stop relying on ancient history and get with the times.

It's all about physics, not ancient history. Valves cannot deliver large amounts of current. Transistors can.



Its not that transistor amps can't have the same ability (as you misqouoted me)


I don't believe I misquoted you. I corrected you. Valves cannot ever hope to deliver the levels of current which can be delivered by transistors. Valves are inherently high impedance devices, which are usually hampered by output transformers. Transistors are low impedance devices, which do not require output transformers.



its that modern valve amps have massive power supplies with high current abilities beyond equivalently priced transitor amps with the same wattage.


Huh? I have a transistor amp on my bench right now, which has the following capabilities:
220 Watts/ channel @ 8 Ohms
430 Watts/channel @ 4 Ohms
800 Watts/channel @ 2 Ohms
1400 Watts/channel @ 1 Ohm
2000 Watts/channel @ 0.5 Ohms (This will cause house fuses/breakers to blow)

It uses a 5,500 VA, split-wound, double C core power transformer and will maintain that output continuously at better than 5% regulation.
The amplifier can deliver 100 Amps continuous current. You can weld steel with this puppy, though it would be an expensive welder.

Find me a valve amp which can remotely approach these specs (particularly the current ability) and I'll be very surprised.



If you are quoting your understanding based upon your own experiences , then I would suggest that your experiences have been limited in the field of modern quality valve amps.
Suggest what you want. You don't know what my experience entails.



In any event, it is the sound that is the issue and I began by tring to explain why, say, a 0.2% THD valve amp can sound better than a O.02 % THD solid state amp.


Well, no, you did not. You began by regurgitating the old misunderstandings about odd and even order distortion and assuming that valves were automatically superior to transistors in this area. Any good text book on amplifier theory will explain where you got that wrong.



The vast majority of musicians around the world who use amps in performances agree.


Musicians CREATE music. The rest of us LISTEN to that creation. Creating and listening are different things.



For the record I have variety of both, and each has its place, but remember the question at the beginning of the thread?


I stand by my original suggestion. Transistor amp and some dummy valves. Stay well clear of cheap, Chinese crap.



This is not the forum to go into the technicalities and experiences in greater detail and we could fill libraries with selective quotes from magazines, but if you are in Perth, I would be happy to show you what I am referring to.

Thank you for your offer, but Sydney has plenty of opportunities for listening to valve amps. I service them every day. I listen to them most days. Some are good and some are bad. On the whole, however, transistor amps (at the very high end) can provide better fidelity and more accuracy.

[TP1]

"Musicians CREATE music. The rest of us LISTEN to that creation. Creating and listening are different things."

Stunning stuff! Its their creation that we listen to! I would back the judgement of a musical artist (and my own ears) any day than a person wielding a soldering iron. For the same reason, I would not buy a motor car purely based upon what a mechanic thought about how the car should meet my needs and closed his mind to its actual performance and other qualities!

"Unfortunately, loudspeakers do not represent a purely resistive load. Look at the impedance curve of this speaker"

Its hard to tell whether you are simply trying to bait me or that you genuinely do not have sufficient experience with listening to and setting up valve amps. Of course impedance curves vary and not all speaker combos will be at their best with valve amps. But that does not mean that they will with transistors either. There are factors beyond impedance which need to be taken into account which is what the whole issue is about - how the speaker actually sounds with a particular amp.

On that score the buyer is the expert because he or she should go for what sound they prefer. Its up to the consumers, you and I and musicians have already made our decisions.


"It's all about physics, not ancient history. Valves cannot deliver large amounts of current. Transistors can. "

Again I can't work out if you are baiting me or have genuinely not looked at the issue from a consumer's perspective. Its not the theory i was talking about, its the actual construction of the solid state amps that are generally made available to the public vs that of decent valve amps.

Consider the average AV amplifier for example, look at the power supplies available to drive the alleged 100 watts per channel. The reality is that they run out of steam when under load, particularly when anything but the most efficient speakers are being used. They wouldn't if they were made better but the fact remains that most of the amps that the public has are like this. This is what I was originally referring to before the thread got hijacked into "transistor vs Valve theory".


Now, of course everyone would know it is possible to build huge power supplies into transistor amps,but the fact remains that in practice, manufacturers do not do this for most of the affordable products that reach the average consumer (remember how this thread began!!).


I ordinarily would love to continue to share relevant experiences in the hope that people would benefit overall. However I don't think that arguing to protect entrenched viewpoints will do justice to this forum.

[Zaphod]

"Musicians CREATE music. The rest of us LISTEN to that creation. Creating and listening are different things."

Stunning stuff! Its their creation that we listen to!


Correct. If the creation of that music involves (say) the use of an amplifier with 8% THD, then it is NOT appropriate to introduce still MORE distortion by using another amplifier with another 8% distortion. As listeners, it is appropriate for us to use an amplifier with minimal distortion.



I would back the judgement of a musical artist (and my own ears) any day than a person wielding a soldering iron.


That is your right and you are entitled to make as many mistakes as you wish. I number many musicians amongst my clients. One is one of Australia's foremost classical musicians. When I attended his system I noted that he had made a fundamental error with his speaker wiring. The system could never have sounded close to correct. Another is in the first violins of the SSO. He operates his system with the treble control well advanced. So much so, that I cannot remain in the same room when it is operating.



For the same reason, I would not buy a motor car purely based upon what a mechanic thought about how the car should meet my needs and closed his mind to its actual performance and other qualities!


Again. I was merely correcting your misconceptions. Just to recap your errors (to paraphrase):

"Class A sounds louder than Class A/B."
"Valves deliver more current than transistors."
"Valve amps exhibit higher levels of even order distortion and transistor amps exhibit higher levels of odd order distortion."
"Valve amps clip more gracefully than transistor amps."

All these allegations are demonstraby incorrect.



"Unfortunately, loudspeakers do not represent a purely resistive load. Look at the impedance curve of this speaker"

Its hard to tell whether you are simply trying to bait me or that you genuinely do not have sufficient experience with listening to and setting up valve amps.


I have more than 40 years experience with valve amps. I've built more than I care to recall. I've serviced thousands of them. I carefully listened to hundreds. And, once more:

A good valve amp can deliver very good sound. A good transistor amp can deliver very good sound. Clear?



Of course impedance curves vary and not all speaker combos will be at their best with valve amps. But that does not mean that they will with transistors either.


Since transistor amps possess a naturally low output impedance, it is possible to design a transistor amp which can drive *any* loudspeaker (much like the amp on my bench right now). It is simply not possible to build a valve amp which can do what a transistor amp is capable of. And yes, for MOST situation, a good valve amp will work just fine.



There are factors beyond impedance which need to be taken into account which is what the whole issue is about - how the speaker actually sounds with a particular amp.


The impedance is fundamental to how the system sounds. As you can see from my previous cites, even very good quality valve amps exhibit frequency response anomalies when loaded by difficult speaker systems. A GOOD transistor amplifier will not exhibit such anomalies.



On that score the buyer is the expert because he or she should go for what sound they prefer. Its up to the consumers, you and I and musicians have already made our decisions.


No one disputes that listeners make the decisions that suits them. I sought to correct your misconceptions. I trust that I have managed to do just that. For the record:

* It is TOPOLOGY (ie: Push pull vs. Single Ended) that determines the nature of the distortion components of an amplifier, NOT the TECHNOLOGY 9ie: Valves or transistors).
* All things being equal, a Class A amplifier of X Watts, will sound as loud (or soft) as a Class A/B amplifier of X Watts.
* Soft clipping can be incorporated into any amplifier technology.
* Transistor amplifier, being low impedance devices, are capable of delivering far more current than a valve amp can.



"It's all about physics, not ancient history. Valves cannot deliver large amounts of current. Transistors can. "

Again I can't work out if you are baiting me or have genuinely not looked at the issue from a consumer's perspective. Its not the theory i was talking about, its the actual construction of the solid state amps that are generally made available to the public vs that of decent valve amps.


Your misconceptions suggested that you were attempting to convey technical details on various amplifiers and topologies. I responded accordingly. Further and for the record, here are some decent transistor amplifiers, which are readily and generally available to the public:


http://www.halcro.com/productsDM88.asp
http://www.me-au.com/html/me850hc1.html
http://www.krellonline.com/krell_component.php?id=86&page=EVOAMPS
http://www.marklevinson.com/products/overview.asp?cat=pa&prod=no532


There are, of course, many other examples.



Consider the average AV amplifier for example, look at the power supplies available to drive the alleged 100 watts per channel. The reality is that they run out of steam when under load, particularly when anything but the most efficient speakers are being used. They wouldn't if they were made better but the fact remains that most of the amps that the public has are like this. This is what I was originally referring to before the thread got hijacked into "transistor vs Valve theory".



You failed to make clear that you were trying to compare expensive mono/stereo valve amplifiers to cheap, home cinema amplifiers. That is hardly a sane comparison. Comparing like with like makes more sense.



Now, of course everyone would know it is possible to build huge power supplies into transistor amps,but the fact remains that in practice, manufacturers do not do this for most of the affordable products that reach the average consumer (remember how this thread began!!).


I've not forgotten how the thread began. I merely sought to correct your misconceptions.




I ordinarily would love to continue to share relevant experiences in the hope that people would benefit overall. However I don't think that arguing to protect entrenched viewpoints will do justice to this forum.

And again: I seek only to correct the misconceptions listed.

BTW: How many interleaves are used in your output transformers?

[Cliff Rogers]

Geeze Liggie, I bet you are glad you asked. :D

I don't know how far your budget will stretch but have a look at some of this stuff.

Beware, it ain't cheap.

http://www.audiophile.com.au/product_almarro.html
http://www.audiophile.com.au/product_cad-exciter.html
http://www.audiophile.com.au/product_cary.html
http://www.audiophile.com.au/product_slp-05.html

[Lignum]

Geeze Liggie, I bet you are glad you asked. :D


Thanks Cliffie… its been one of the better hijacks for years. :D

Your links are great, way out of my price range but the configuration of the vales is of real interest as I will go with great advice from Zaphod of using valves in a fake way with separate power, as I already have the choice of an older NAD or Cambridge Audio amp. Also will have a Rotel tuner, and looking at an old Duel TT that plays 78`s and I want to add blue tooth and internet radio. Below is the full scale drawing of the cabinet and will be made from Walnut, Macassar Ebony and Black bean. Will be a fun project and I might do a WIP

[Zaphod]

Thanks Cliffie… its been one of the better hijacks for years. :D

Your links are great, way out of my price range but the configuration of the vales is of real interest as I will go with great advice from Zaphod of using valves in a fake way with separate power, as I already have the choice of an older NAD or Cambridge Audio amp. Also will have a Rotel tuner, and looking at an old Duel TT that plays 78`s and I want to add blue tooth and internet radio. Below is the full scale drawing of the cabinet and will be made from Walnut, Macassar Ebony and Black bean. Will be a fun project and I might do a WIP

Nice. As for valves, WES Components is a good choice, if you're in Sydney. EVATCO in Melbourne has a HUGE range. Of course, you can always scrounge second hand valves from all sorts of places. There's a guy in Melbourne who I sourced some valves from a few years back. They were very inexpensive (because no one else wanted them), but, since they were for a similar purpose to yours, they worked just fine. A couple of things to be aware of:

* Big valves look cool (if you know what I mean), but they can consume large heater currents. Some Russian valves consume several Amps. This can mean a large, dedicated heater supply. Small valves (stuff like 12AX7, 12AU7, et al) don't require much in the way of heater current.

* WES supply some very attractive ceramic valve bases for reasonable prices. Again, in Melbourne EVATCO would be the people to see. They all do mail order wherever you happen to be.

* A big valve (6550, KT88, 6CA7 et al) will dissipate around 10 Watts in heater power, so will not get excessively hot, but you will need to arrange for that heat to escape, if damage is not to be caused to surrounding (usually above) timber. Small valves (12AX7, et al) will dissipate around 2 Watts.

Should be a fun project. Ask around for valves which have poor 'emission' but a working heater. You may find that someone has saved some nice looking ones (for whatever reasons) and is willing to part with them for not too much cash.

One thing to watch for: DO NOT buy any valve which has a white powdery residue inside. That indicates the valve is 'gassy'. Some of the vaccuum has escaped (??!!). The heater will not last long under such conditions.

[watson]

Thank you Linesmen...Thank you Ball boys.
Answer to original question received.