Hi Richard,
Yes, what you are doing and have done will improve life for a village if you look years into the future. Of course this also benefits you as you can look back on it with great satisfaction. You made a difference in the world and the people in the village know it.
It's up to people like Wally to actually try the filtering. They don't have to report what they actually observed of course. So there is no risk to their ego over this test. Education.
-Chris
Yes, what you are doing and have done will improve life for a village if you look years into the future. Of course this also benefits you as you can look back on it with great satisfaction. You made a difference in the world and the people in the village know it.
It's up to people like Wally to actually try the filtering. They don't have to report what they actually observed of course. So there is no risk to their ego over this test. Education.
-Chris
Zappa ain't smart but people with money are, gotcha, hope you voted for the smart guy in charge.
True, and easily measurable distortions. You should be careful Papa wears a white hat and has a BIG posse.
I'm thinking of trying a version of Mark's M2 project since I have some old MOSFET output stages on heatsinks lying around. In the past I was not happy with a pair of 6L6's driven with an interstage step up transformer for gain, but I might get better results with this. This has it all no PSRR, auto-transformer step up, coupling capacitors.
I am sure that with your experience as an audio designer, your perfect objectivity and your (real) deep knowledge, you will publish your scientific and extensive study about the thresholds of audibility of signal/noise, HD, IM, phases and bandwidth etc.. of the human race.
You will have your name in the audio hall of fame, near the ones of Fletcher and Munson, a Page in Wikipedia,
and I will light a candle in your honor because you will save a lot of time of the little that I have left to live.
As for Nelson, there is some reasons why he is called "Papa".
- He is famous for its "good sounding" designs, some very far from the old worn roads that seem the only ones allowed here. With sucessful results.
- He is open minded, curious, benevolent and friendly, never try to contemptuously reduce people as members of a "crowd".
- He never(for what I have seen) try to walk out of his competency domain, never try to impose his points of view, neither try to hold a guru position in front of a troop of admiring inexperienced handymen.
- He use his ears that seems totally logical when it is about "Audio".
(The Second sentence of the Wikipedia page about him
"Pass is vocal that listening tests remain valuable and that electrical measurements alone do not fully characterize the sound of an amplifier"
- He could be my dad if i was not older than him ;-)
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Yet another illustration of the real agenda here. And once again, true enthusiast DIY.
I know...they just started and they dont know English well. I have to beat them up about that. It's a work in progress. Normally, it is all in Thai. But, they will get it done in English soon.
-RM
We are still waiting for any measurements. So far all sighted testing and therefore unfortunately anecodatal. Howie is the odd one out here.
So by your reasoning as long as everything in the house has been made since 2000 or so there is not issue as it meets the legal requirements.
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One of the 7 uses batteries, another is about to use batteries. Another lives in the **** end of beyond and has very clean power.
Note zero measurements have been given for the efficacy of big hunks of iron in a normal domestic environment for home audio. none, nada, zip.
Scott is an amazingly experienced designer, just his fields are way above the requirements of audio. I hear his mic preamp is not too shabby though and Walt Jung does credit him with the critical piece for his composite line stage, so a few crumbs of audio there. Jneutron OTOH knows way too much about everything and I am convinced he is an alien trying to drag human science to the point where he can make enough dilithium to get his craft out of hock in roswell.
His point was that the Pass labs guys don't sweat -130dBc measurements. Nelson is open about wanting a 'nice' sound and interesting topologies to get there. He accepts it's entertainment, Richard seems to think it's dialysis.
It's not good in Thai either. I could build a Square website in 5 minutes that is better.
That has matrices in it, you won't get many people to read that, despite it being (at least to me) rather interesting.
No PSRR? I think you might have forgotten that there are no common source (or common emitter) stages in the FirstWatt M2. It is a 3 stage amp:
Stage1: Complementary JFET (push pull) source follower. Supply = drain.
Stage2: Transformer. No connection to supply.
Stage 3: Complementary MOSFET (push pull) source follower. Supply = drain.
Stage2: Transformer. No connection to supply.
Stage 3: Complementary MOSFET (push pull) source follower. Supply = drain.
Certainly there exist FirstWatt amps that use common source output stages, whose PSRR may be more problematic. But the M2 is not one of them.
Sorry Mark my bad I was responding to the generic First Watt comment, I have only started to look at the M2 circuit.
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Scott, you may be extra-pleased with the First Watt M2x amplifier using the "Norwood" input stage daughter board. It replaces the complementary JFET push-pull first stage, with {an 8-legged AD744 + video speed line driver + lots and lots of local supply bypass}. Since the input stage is positioned before the voltage amplification, lousy PSRR at the IPS gets multiplied by downstream gain. On the other hand, improvements to PSRR at the input stage, get passed along to the output as improvements x gain. And the AD744 has better PSRR than the complementary JFET stage, especially so at 120 Hz and harmonics thereof.
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