6922 vs 6SN7

[DF96]

Of course, but hopefully amps so celebrated has solved, not all, but most problems in their circuit design, as to give the listener a good impression of what the type of tube should sound like at its best.

Commercial amps (and some DIY designs) routinely include basic circuit mistakes. Their consequences can sometimes be seen in measured results (in those magazines which do measurements) but they are almost always waved away by the reviewer (as in most cases he can't read a circuit diagram). The risk of such problems seems to increase at the very low and very high price points. A 'celebrated' amp is particularly likely to suffer, given the likely technical knowledge of those who 'celebrate' amplifiers.

 

[denny9167]

I think we're comparing apples and oranges here, for one the difference in gain. There are others but that's the first thing that comes to mind.

 

[Bob Richards]

I agree that most (maybe all) reviews are dollar orchestrated. I want to get a job selling used/refurbished stereo equipment, but I can't because I am unwilling to tell someone they should spend $500 on speaker cables, when I know that 50 cents a foot 16AWG AC line cord bought at any hardware store is just as good (for up to at least 20ft per cable). I worked in video engineering at Tektronix, and cinema products engineering at Dolby Labs, Two Prosound companies and many other places. I picked the brains of many really great Engineers. I have yet to hear of a legitimate ABX or whatever blind test that showed that anyone can hear any difference in cables in an audio system. I could go on and on. It's all about the dollar and tricking people into believing all kinds of bull sh*t. That's not who I want to be. Sorry to be off subject here.

 

[Rewind]

Commercial amps (and some DIY designs) routinely include basic circuit mistakes. Their consequences can sometimes be seen in measured results (in those magazines which do measurements) but they are almost always waved away by the reviewer (as in most cases he can't read a circuit diagram). The risk of such problems seems to increase at the very low and very high price points. A 'celebrated' amp is particularly likely to suffer, given the likely technical knowledge of those who 'celebrate' amplifiers.

What is the reason that a science that has been going on for the last 80 years or so, has not made a perfect design for each kind of popular tube type (45, 2A3, 300B, EL84, 6L6), that everyone can follow?

 

[TonyTecson]

Commercial amps (and some DIY designs) routinely include basic circuit mistakes. Their consequences can sometimes be seen in measured results (in those magazines which do measurements) but they are almost always waved away by the reviewer (as in most cases he can't read a circuit diagram). The risk of such problems seems to increase at the very low and very high price points. A 'celebrated' amp is particularly likely to suffer, given the likely technical knowledge of those who 'celebrate' amplifiers.

i have a nagging suspicion that some designs are deliberately made to produce the kinds of distortions that the audiophile crowd craves for....

 

[Miles Prower]

What is the reason that a science that has been going on for the last 80 years or so, has not made a perfect design for each kind of popular tube type (45, 2A3, 300B, EL84, 6L6), that everyone can follow?

How does one define "perfect" here? That's a big problem right there. Secondly, the end users aren't all using the same speeks. Even if a design were "perfect" with one particular set of speeks, it would be sub-optimal when connected to a different set with different impedance/frequency performance.

Every design is, by necessity, filled with compromises.

 

[DF96]

What is the reason that a science that has been going on for the last 80 years or so, has not made a perfect design for each kind of popular tube type (45, 2A3, 300B, EL84, 6L6), that everyone can follow?

There are no perfect designs. Engineering is always a compromise between competing aims.

However, the knowledge exists to do good designs and many use it. Some can't or won't. Whether a design is good depends on many things, including context. There is no such thing as a 'perfect' design using, say, EL84 which everyone can copy - although datasheet recommendations can come close to this. Datasheet designs tend to run valves very hot to get best performance at the risk of short life - which suits the manufacturer for both reasons! So another designer aiming for long product life will run a bit cooler and accept a bit less power and a bit more distortion. Different set of compromises.

i have a nagging suspicion that some designs are deliberately made to produce the kinds of distortions that the audiophile crowd craves for....

Yes, I suspect that too. The alternative is to assume that the designers of some audiophile gear are simply incompetent.