It seems to me that cancelling the output impedance of Q2, Q4, and R31 will increase the open loop gain rather than the open loop bandwidth (??). Stage2 gain is gm*Rload and you are making Rload appear to be infinity, thus driving gain to infinity. Is it not so?
To break free from BW=gm/C wouldn't we need to either make gm appear to be infinite, or make C appear to be zero ?
You have not followed the story, there is supposed magic in having only 80dB OLG out to 20k as opposed to 120dB out to 200Hz.
Presumably in reference to the story here, "Then unity gain crossover > 16 MHz and therefore open loop bandwidth is greater than (16 MHz / 32.8dB) = 368 kHz. That's a pretty good-sized OLB."
Which eventually led to the unanswered question, "To break free from BW=gm/C wouldn't we need to either make gm appear to be infinite, or make C appear to be zero ?"
To which looping in the positive feedback increases the DC gain markedly, so instead of 16 MHz/ 32.8 dB, you're looking at 16 MHz / 60 dB == far less OLB even if the UGBW remains constant.
The point is that OLB is a relatively meaningless metric as that's a waste of perfectly good LF loop gain. That's it.
The point is that OLB is a relatively meaningless metric as that's a waste of perfectly good LF loop gain. That's it.
To read for fun : JC-2
http://www.americanradiohistory.com/Archive-Audio/70s/Audio-1976-04.pdf
>>page 64
http://www.americanradiohistory.com/Archive-Audio/70s/Audio-1976-04.pdf
>>page 64
I missed my chance to see Dick's system, they say his recording of an F-15 taking off from Hanscom field is painfully loud.
I have never seen Dick's system either, but I did hear F-15's take off at Hanscom Field! 1973 iirc.
Yes, painful.
Jan
Thank you.... try this one...
View attachment DAC3 vs DAC 2.pdf
I am particularly interested in the 2H and 3H harmonic removal technique.
-RNM
I grew up a mile from the end of McCllelan AFB runway, supply and repair depot for the Pacific. I never want to hear another F-15 takeoff with full afterburners again. It was a common occurrence during the Viet Nam war. Not to mention the static testing of jet engines, even behind the berm.
Cheers
Alan
Cheers
Alan
Didn't the US involvement in the Vietnam War end with the fall of Saigon in April 1975? I ask because the F-15 did not enter into active military service until 1976 according to Wikipedia, image below. It took McDonnell Douglas 3.5 years to flight test the F-15, get USAF okay, and then build enough planes to deploy on active duty.
_
Attachments
The potato vs banana interconnect test is http://www.diyaudio.com/forums/members/pano.html job
F-4 (Phantom) in Vietnam war
George
I grew up not much further from McClellan AFB .... sonic booms were regular occurrences as was low flying over houses. So low you can see the head of the pilot as he passed by. I still remember the on-coming and going scream of the engines.
I can imagine a group of them bearing down on you (as enemy) was a terrifying moment. You would hear that engine scream before you saw the plane ... you knew it was only seconds before you would see it and then all hell was going to break loose on you.
-RM
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so maybe my attribution is off, doesn't change the number of jets going in and out of the base. The air force's cavalier attitude towards those near them was not particularly appreciated, it did make for some good surplus houses.
Alan
I expect it to be marginally popular because the imbalance on RCA might make it sound unique, and the hordes of RF on "XLR" are sure to be a crowd pleaser. I have no idea why so many pieces of it look chewed on...
The only interesting thing is it provides more compression it appears, than all the mismatches of tolerances on RCA. Well, I am curious about foil inductance vs capacitence for cables, maybe it could work well but isnt required to connect like that. Really though I just thought everyone would see as much humor as I do in it. While I think copper connectors are best, I have a lot of Radioshack terminated cables that with my high quality wire are fantastic and easily stood up to things that cost a lot. There is a diminshing returns factor to connectors generally. But if you replace some poorly shaped ones with better shapes it might be fairly noticable; people swear tube connectors sound better than the wonky shaped average binding posts.
The only interesting thing is it provides more compression it appears, than all the mismatches of tolerances on RCA. Well, I am curious about foil inductance vs capacitence for cables, maybe it could work well but isnt required to connect like that. Really though I just thought everyone would see as much humor as I do in it. While I think copper connectors are best, I have a lot of Radioshack terminated cables that with my high quality wire are fantastic and easily stood up to things that cost a lot. There is a diminshing returns factor to connectors generally. But if you replace some poorly shaped ones with better shapes it might be fairly noticable; people swear tube connectors sound better than the wonky shaped average binding posts.
I am rather surprised that there are any SCP-1's left in service. I haven't made one for about 30 years. The real difference in the SCP-1's from early to late 1983-1988 is only obvious by looking at the circuit board. If it is tin plated, it is early. If it is gold plated, it is late. There are internal power supply differences too.
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