Yes!
I might be wrong but I don't know of any large scale integrated opamps in which the output stage can operate Class A. A discreet op amp or tube preamp can run rings around them as far as headroom and low distortion at a large output swing and the entire circuit can operate Class A. The recording industry is hopelessly tied to Madison Ave and I feel that they are not interested in the least at providing any semblence of quality. If Madison Avenue Can convince the sheep to like **** then rest assured, we'll get **** Ray Hughes
I might be wrong but I don't know of any large scale integrated opamps in which the output stage can operate Class A. A discreet op amp or tube preamp can run rings around them as far as headroom and low distortion at a large output swing and the entire circuit can operate Class A. The recording industry is hopelessly tied to Madison Ave and I feel that they are not interested in the least at providing any semblence of quality. If Madison Avenue Can convince the sheep to like **** then rest assured, we'll get **** Ray Hughes
"I might be wrong but I don't know of any large scale integrated opamps in which the output stage can operate Class A."
http://www.dussun.com/english/v8.html
http://www.dussun.com/english/v8.html
Marantz 7C line amp
I built a clone Marantz 7C line amp with 12AU7 for the last buffer stage. My friend tried it out in his system with Phase Linear 200W solid state power amp and JBL speakers.
He mentioned to me last night that it sounds so sweet that he must build one himself......
What can I say??
Johnny
I built a clone Marantz 7C line amp with 12AU7 for the last buffer stage. My friend tried it out in his system with Phase Linear 200W solid state power amp and JBL speakers.
He mentioned to me last night that it sounds so sweet that he must build one himself......
What can I say??
Johnny
In an earlier post RDF states that tubes are capable of a level of performance where their short comings are difficult or impossible to measure. This is true enough, but most tube preamps use a simple triode buffer/gain stage. This kind of stage has performance limitations that are quite easy to measure. In short, the simple triode design tends towards fairly high levels of even distortion products.
Many people have said that the correct pursuit of an audiophile is a search for sonic accuracy, a nice platitude, but probably not all that correct.
I've built my own projects and find that I'm pursuing enjoyment not accuracy. From comments in this thread so are many of you. A little boost in the mid bass a little roll-off in the treble tends to reduce many ills of the commercial recording industry.
When people say things like, I like a tube pre with a SS amp or visa versa they are probably equalizing for enjoyment not for accuracy. I don't think there is anything wrong with this. With commercial sources such as CD, a great many sonic sins are beyond our control. Taming them with a non ideal design seems reasonable enough. This probably goes some of the way in explaining why SS, vacuum tube and passive designs continue to exist, if one was a clearly superior answer, the other two would disappear soon enough.
Many people have said that the correct pursuit of an audiophile is a search for sonic accuracy, a nice platitude, but probably not all that correct.
I've built my own projects and find that I'm pursuing enjoyment not accuracy. From comments in this thread so are many of you. A little boost in the mid bass a little roll-off in the treble tends to reduce many ills of the commercial recording industry.
When people say things like, I like a tube pre with a SS amp or visa versa they are probably equalizing for enjoyment not for accuracy. I don't think there is anything wrong with this. With commercial sources such as CD, a great many sonic sins are beyond our control. Taming them with a non ideal design seems reasonable enough. This probably goes some of the way in explaining why SS, vacuum tube and passive designs continue to exist, if one was a clearly superior answer, the other two would disappear soon enough.
Hi Rich,
If you are referring to Luxman, with those glowing tubes behind the front panel.... Yes, those tubes are in the audio circuit. Make no mistake. The Carver C-19 preamp also uses 6DJ8s in the audio path. Along with a ton of op amps he is so fond of. Odd mix that did sound better than his other preamps of that period.
Me? I like both tube and solid state, as long as they're good. So does my wife.
-Chris
If you are referring to Luxman, with those glowing tubes behind the front panel.... Yes, those tubes are in the audio circuit. Make no mistake. The Carver C-19 preamp also uses 6DJ8s in the audio path. Along with a ton of op amps he is so fond of. Odd mix that did sound better than his other preamps of that period.
Me? I like both tube and solid state, as long as they're good. So does my wife.
-Chris
hermanv said:
Not exactly. For some reason contemporary numbers are hard to come by but I don't recall any studies (corrections welcome) demonstrating that distortion much below 0.1% second harmonic is audible under any circumstance. A dual compactron headphone amp on my bench reaches deafening levels at less than a third that amount and at typical listening levels well under a tenth. By no scientifically recognized metric I understand is that performance any less than audibly perfect. That it's tube based is irrelevant, as is the fact a SS HP amp might do a 90% less distortion still at the same levels.
Science ascribes a threshold performance mertric beyond which, as far as recognized it's concerned, all devices sound identical. Statements regarding sound quality past this point are voodoo, one I freely admit to practicing (minus candles and chickens.) However, statements proclaiming my headphone amp for example are anything less than sonically perfect from a scientific perspective are voodoo as well.
As you know the threshold of audibility of effects is a hotly debated subject. There is no imaginable reason why audiophiles should be able to hear different conductive metals used in cables, but they appear to be able to do so.
Like many things the threshold of detection varies a lot from one individual to another, worse I firmly believe you can "educate" your ears to hear ever smaller problems with increased attention and training.
I would find it quite dangerous to assign a hard value to these kinds of phenomena. 16 bit PCM has a distortion/noise floor of around 0.015% many people hear either SACD or 24/96 as sounding better, even though it's below the "audibility threshold". I know I'm simplifying a complex process and don't particularly want to get involved in a debate about where the numerical threshold is. I'm pretty sure that current beliefs and measurements of a random population cross section are not the last word.
Like many things the threshold of detection varies a lot from one individual to another, worse I firmly believe you can "educate" your ears to hear ever smaller problems with increased attention and training.
I would find it quite dangerous to assign a hard value to these kinds of phenomena. 16 bit PCM has a distortion/noise floor of around 0.015% many people hear either SACD or 24/96 as sounding better, even though it's below the "audibility threshold". I know I'm simplifying a complex process and don't particularly want to get involved in a debate about where the numerical threshold is. I'm pretty sure that current beliefs and measurements of a random population cross section are not the last word.
Re: Yes!
Class A operation of AB biased output stages is determined by the load impedance and Vswing
for a preamp in consumer audio application - driving ordinary sensitivity power amps' input attenuators of > ~5 KOhm there are in fact a number of monolithic op amps that run Class A if you haven't totally screwed up your system gain structure
the "hottest" A/DSL driver op amps may give as much as +/-10mA Class A output from complementary bipolar, dielectric isolated GHz Ft transistors - their market has them directly compete on HD/IMD into 25/50 Ohm loads at 100K-1 MHz signal frequencies ( -80 to -100dB HD2,3 ) - I'm pretty sure audio frequency crossover distortion is simply not a concern with these op amps
grhughes said:
Class A operation of AB biased output stages is determined by the load impedance and Vswing
for a preamp in consumer audio application - driving ordinary sensitivity power amps' input attenuators of > ~5 KOhm there are in fact a number of monolithic op amps that run Class A if you haven't totally screwed up your system gain structure
the "hottest" A/DSL driver op amps may give as much as +/-10mA Class A output from complementary bipolar, dielectric isolated GHz Ft transistors - their market has them directly compete on HD/IMD into 25/50 Ohm loads at 100K-1 MHz signal frequencies ( -80 to -100dB HD2,3 ) - I'm pretty sure audio frequency crossover distortion is simply not a concern with these op amps
A significant percentage of valve fans subscribe to the KISS philosphy with the need to reduce the number of gain stages and the amount of feedback. This philosphy can produce some of the most "listenable" systems imaginable. They score highly on ambiance and micro-detail and naturallness.
Opamp and transistor amps/preamps have complex signal paths and in general enforce exactly the opposite approach to design. As a result those precious qualities suffer. When all's said and done that seems to be the reason why valves score over SS. KISS and valves go hand in hand and simply using a single opamp and a few top quality components will not come close.
This whole area goes far beyond what is measurable in a traditional sense and so it seems to me that, within reason, quoted figures are largely unimportant.
I tend to agree. My current main amp has a slight high frequency roll off and in a listening test with some golden ears, it was found to sound the most pleasing amp out of 5 others.
Shoog
Opamp and transistor amps/preamps have complex signal paths and in general enforce exactly the opposite approach to design. As a result those precious qualities suffer. When all's said and done that seems to be the reason why valves score over SS. KISS and valves go hand in hand and simply using a single opamp and a few top quality components will not come close.
This whole area goes far beyond what is measurable in a traditional sense and so it seems to me that, within reason, quoted figures are largely unimportant.
I tend to agree. My current main amp has a slight high frequency roll off and in a listening test with some golden ears, it was found to sound the most pleasing amp out of 5 others.
Shoog
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