I think we should go on with something else. We may yet be able to make some progress in measurement of either active or passive devices, if we try to focus on it.
The author claims that electrostatic fields effect the resistor.
Fast read - but it is unclear if the author refers to all resistors or just those that have shields for magnetic fields?
Also the construction of these shields didn't make a lot of sense just glancing at the diagrams... ymmv.
_-_-bear
If you look at their actual product data sheet there is no shield (apparently) and they offer a directional version at additional cost. I guess which way to point it is up to the user.🙄
Or you could buy two of each and connect them in reverse parallel to get the preferred sound in both signal directions.🙄
Please everyone, instead of making fun of various elements, let us evaluate them objectively.
The japaneese traditionally care a lot about direction.
Some time ago i had a discussion with a japaneseese high end freak that asked me what way around i mount resistors caps and COILS. For him it made a big difference. I spare you my opinion this time.
Some time ago i had a discussion with a japaneseese high end freak that asked me what way around i mount resistors caps and COILS. For him it made a big difference. I spare you my opinion this time.
Thanks Joachim. I am only the messenger on this topic. I have heard about it, but I personally have not any specific opinion on it.
Without trying to get into the subjective aspect of this direction issue, even if you had an empirical way to measure some aspect of the directionality (like the field of an inductor, or the pick up of impinging energy by said inductor) one could spend a very long time flipping parts one way then the other and testing... in even a normally minimal bit of gear that would cause one to flip "stuff" so many times that there is not likely to be a definitive way to determine what is what, much less what "sounds" good.
One big problem is that even if one found that one "way" was best in theory, in an actual circuit situation that way might not be best given what else is going on around that component.
Which brings up the idea that maybe everything should be shielded? (working in isolation)
But what of the added capacitance due to "shielding"??
What of leakage due to shielding?
And, does it or would it be valuable to actually enclose/encapsulate circuitry inside metal, or mu-metal cans, with just the goesinta and goesouta pins emerging... sort of like what FM Acoustics does by potting their active elements, or some professional mixboard builders do/did?
_-_-bear
One big problem is that even if one found that one "way" was best in theory, in an actual circuit situation that way might not be best given what else is going on around that component.
Which brings up the idea that maybe everything should be shielded? (working in isolation)
But what of the added capacitance due to "shielding"??
What of leakage due to shielding?
And, does it or would it be valuable to actually enclose/encapsulate circuitry inside metal, or mu-metal cans, with just the goesinta and goesouta pins emerging... sort of like what FM Acoustics does by potting their active elements, or some professional mixboard builders do/did?
_-_-bear
Jan Lohstroh's interview is very good, but it is more superficial on the subjects of discussion here, today, because Jan has not been involved with these problems as we have, in the audio industry in the past decades.
It IS interesting that the so called Otala power amp, an example of which that I have running in the other room, was built by a third party in a pretty poor and amateur manner. It is an attribute to the original circuit designer, Jan Lohstroh, that the circuit sounds so good, even with the marginal components used in many spots. It should be noted, as well, that without Matti Otala's input, this design would have not been extraordinary sonically, above and beyond other amps at the time.
It IS interesting that the so called Otala power amp, an example of which that I have running in the other room, was built by a third party in a pretty poor and amateur manner. It is an attribute to the original circuit designer, Jan Lohstroh, that the circuit sounds so good, even with the marginal components used in many spots. It should be noted, as well, that without Matti Otala's input, this design would have not been extraordinary sonically, above and beyond other amps at the time.
Thank you John. IIRC, Matti's input were mainly his insistence on the higher-than-usual bias current in the various stages, to improve slew rate, which as you know was a big item for Matti.
As for components, they being employed at Philips, had access to everything Philips produced, including power transistors that were considered pretty fast at the time, but not anything exotic from the competition (if that existed at all at that time).
An interesting bit of history, for sure.
jd
Open loop bandwidth was important, as well. That is one of Matti's design rules. I did the same thing, in Switzerland, and that became the ML-2 power amp.
Motorola made output devices, just as fast, and more powerful than the output devices used in the 'Otala' amp. I used the 2N5884-6 pair for many years, with great success.
Motorola made output devices, just as fast, and more powerful than the output devices used in the 'Otala' amp. I used the 2N5884-6 pair for many years, with great success.
PS If you want to know how Lohstroh looks after 30+ years, 😉 there is a link to a video of him playing the Steinway at the top of my homepage Jan Didden audio diy and other human frailties place .
jd
jd
As this is the BLOWTORCH thread, I might emphasize that the open loop bandwidth of the Otala amp is higher than Jan Lohstroh would have done on his own, or perhaps even today, if he had to do it again. However, I first evaluated this unit in 1975, and even purchased the first prototype made in Oslo at that time. I used this amp, off and on, for another 16 years, ultimately driving my WATT PUPPIES until the firestorm in 1991. I have a second unit now, and it exceeds the sound quality of my cheaper units, with even better circuit topology. The only real difference is that my Parasound designs have to have more power, and lower distortion for a given number of devices, and this forces me to use MORE negative feedback with a lower open loop bandwidth.
If Jan Lohstroh had designed this amp as an OP AMP, it would have not been successful in the audio marketplace.
If Jan Lohstroh had designed this amp as an OP AMP, it would have not been successful in the audio marketplace.
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