Apart from geeks with software thinking they know how to build hi-fi systems, not very .. 🙂
Carry On ........
Carry On ........

Sorry for input.
I have tried to find too from here http://www.diyaudio.com/forums/atta...wtorch-preamplifier-part-ii-preamp_detail.jpg
Forgive me if it presents some absurd
Thanks eD. Not at all. Looks like the same circuit and answers the question.
I also found a post from PMA stating it performed better than 130dB S/N at 1VRMS. Reasonable figure of merit for now based on the input devices and R of the R/C at the input. 🙂
Dave
Originally Posted by dvv
It happens sometimes
OK
(and no, I am not taking any drugs)
You mean, not today 😀
(To me, 600mA quiescent current would read as 11.5W peak, and close to 6W continuous class A power. Pretty hefty for a nominal 25W power amp)
If memroy serves, Otala & Lohstroh postulated that an amp should be running in pure class A up until -17 dB of nominal power.
Their specs state that with 600 mA of bias current it is running in pure class A up until 2.9W into 4 Ohms.
At my age, I’d better quit the old lusts (eat late at night)😀😀
...
Yeah, I just turned 61 and I too have to compromise.
So, now I chase girls only downhill. 😀
Originally Posted by dvv
So, now I chase girls only downhill.
😀
Get them to chase you 😉
Yeah, I just turned 61 and I too have to compromise.
So, now I chase girls only downhill. 😀
Life expectancy in serbia is 75 , you still have time to finish the centurion turbo...
😀
If memroy serves, Otala & Lohstroh postulated that an amp should be running in pure class A up until -17 dB of nominal power.
Their specs state that with 600 mA of bias current it is running in pure class A up until 2.9W into 4 Ohms.
Thats the same thing Jacco said .... 🙂
If memory serves, Otala & Lohstroh postulated that an amp should be running in pure class A up until -17 dB of nominal power.
For a nominal 25W continuous power amp, that's half a watt.
What I was saying was that, combined with a loudspeaker that has an efficiency over 90dB/W/m and an easy impedance, it's as good as a class A amplifier.
(an often read half-wit definition of a class A amplifier, is that dissipation is as high as nominal power output. Just the output stage devices of the 25W Otala already dissipate 28.8 watt)
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Sorry for input.
I have tried to find too from here http://www.diyaudio.com/forums/atta...wtorch-preamplifier-part-ii-preamp_detail.jpg
Forgive me if it presents some absurd
PMA you took out my 8-legs and put the other guy's in, never accuse me of not being a good sport. 😀
What would you have used in their place ?
There were no part Designation for the opamps in your schematics.
Patrick
There were no part Designation for the opamps in your schematics.
Patrick
What would you have used in their place ?
There were no part Designation for the opamps in your schematics.
Patrick
It was a joke, I would of course not have used those. 😉. It depends on the final application since a huge range of parts work, I've used AD4898-2 and AD813. I'm not a big op-amp roller, as you know.
Unfortunately, the engineers are not heard often enough, they take a strictly back seat to the bean counters and whizz kids babbling about "product niches", "competitive prices" and "aggressive marketing". Engineers deal with real world things, often measurable, not pie-in-the-sky concepts.
which brings us to the incredibly important point: if they be that way, and live that way, then they have no voice and are entitled to no voice or opinion, whatsoever, in the area of discovery. To keep their dogma to themselves.
it is an entirely logical and correct point to say so.
If they wish to comment on discovery and experimentation/observation, they are required to put in many a year of exploration and openness without the slightest form of dogma or factualization in their minds, whatsoever. to do this before a single comment emerges from them on discovery and invention. A place where dogma cannot exist as it inherently snuffs out discovery before it begins.
Again, entirely logical and reasonable.
So, in effect, if a an engineering mind can put down the bibles...and move away from being a mid-level cleric, and stop writing up papal bulls for executing blasphemers of the dogma...then we can talk exploration.
You actually don't believe that they can change their 'nature' do you?
They do remind me of mid-level clerics about 400 years ago.
They do remind me of mid-level clerics about 400 years ago.
You actually don't believe that they can change their 'nature' do you?
They do remind me of mid-level clerics about 400 years ago.
I didn't know you were that old..
jn
KBK,
Don't confuse the norm of an engineer's work and the work of a so called engineer/researcher. Two very different disciplines that overlap. Both require a very broad based education to perform their duties and those skills so often overlap, but the engineer is tasked with a specific end goal in mind and uses their education to performs those tasks to the highest known standards. The researcher or inventor has to look past their known knowledge base and try things that they have no preconceived notion of the outcome, they have to allow for failure and the unknown. More is often learned from the failures than from the easy successes.
Don't confuse the norm of an engineer's work and the work of a so called engineer/researcher. Two very different disciplines that overlap. Both require a very broad based education to perform their duties and those skills so often overlap, but the engineer is tasked with a specific end goal in mind and uses their education to performs those tasks to the highest known standards. The researcher or inventor has to look past their known knowledge base and try things that they have no preconceived notion of the outcome, they have to allow for failure and the unknown. More is often learned from the failures than from the easy successes.
Oh, but I can read a book, JN, that quotes 'experts' from many centuries. You perhaps belong in it. '-)
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