John Curl's Blowtorch preamplifier part II

[bcarso]

Despite their diy unfriendliness SM devices do enable some significantly higher-performance designs, even for mostly-discrete components --- wonderful though the achievements of modern integrated circuits may be, and certainly the only alternative for seriously high frequencies.

If I could persuade my former employer to let me cart off the spectrometer, the finishing refinements on which date back to about 1981, I'm sure I'd be amused to see how I managed to get performance out of what today look like hideously large components, the smallest of which were TO-18 and TO-72 metal case devices. Construction was point-to-point on two-sided-copper-clad boards, with some connections made with bus wire and teflon tubing. Although clock driver speeds probably didn't need to be as high as was managed, it was fun to see how well things could be made to work. At one point in the development, with some subassemblies already complete and functional, some end-of-year money appeared and got spent on a 200MHz scope and 900MHz active probe. I suddenly could see a lot of fine structure everywhere and this drove significant modifications, as well as additional delays which further endangered my employment.

When the instrument was first powered up of course it didn't work. But two weeks later it did, this after about four years of design and construction. The word on the street was It will never work (enemies) and It will take a year at least of debug (friends). Some of the enemies finally amended their story to Well maybe it will work for a while.

[Wavebourn]

Originally Posted by SY

Is that the ones I heard at your house? If so, they were surprisingly good.

No, you heard arrays made each with 24 drivers from police motorcycles. If some audiophile magazine knows that they would sing Anathema to Wavebourn.

[jneutron]

Originally Posted by scott wurcer

The numbers are 5-10x less on todays SMT packages OTOH we are trying to make 10G TIA's. If you check the AD8010 datasheet you will see a bypassing scheme that was necessitated by bond wire mutuals, that gets pretty amazing diff gain and phase with lots of parallel video loads.

Any of it BGA/flipchip, or do they all have wires?

Originally Posted by simon7000

If you ever need any small quantities, let me know I still have scraps left over. Normally we get "Thick" triax on 3500' put ups for stadium use. Any length under 300' is scrap.

Although with the high price of scrap we actually are getting rid of some of it.

Thanks for the offer. Copper is kinda pricey.. we take the cuts and send them off to recycle, ours go 12/2 up to 535kcmil, but never longer than 2 or 3 meters.

j

[Positron]

(**)Talk about God existence (hypothesis)
Besides, both men were long dead by the time things were becoming hot with aether-based valid electromagnetic theories.

Not to belabor, but when I was traveling to college way back then, one morning my car would not start, not even a solonoid click. Had 6 hours to drive.

Put jumper cables on, tried three times and not even a click, so turned key off position for 4th time. Waited a couple of minutes, prayed to God, said Amen, and heard something. Looked over and the engine was cranking like crazy. So reached inside, turned the key to on position, and engine started. No starter motor grind, problems etc. Drove to college, parked it and never tried starting it again. Sold it for 70 bucks.

Back to the subject at hand. Let's see if we can reach 3 million hits.

Cheers.

[scott wurcer]

Originally Posted by jneutron

Any of it BGA/flipchip, or do they all have wires?



Thanks for the offer. Copper is kinda pricey.. we take the cuts and send them off to recycle, ours go 12/2 up to 535kcmil, but never longer than 2 or 3 meters.

j

BGA often has a die bonded to a substate but we can put the solder balls right on top of active silicon and flip the whole thing directly onto the board, 3D chip stacking too. Packing density and power are the biggest concern these days, some of this stuff is crazy.

350KCM is the next step up on 4/0, probably only needed for your 1 Ohm speakers. I once looked through a battery/cable catalog for electric locomotives, the shipping will kill ya.

[jneutron]

Originally Posted by scott wurcer

BGA often has a die bonded to a substate but we can put the solder balls right on top of active silicon and flip the whole thing directly onto the board, 3D chip stacking too. Packing density and power are the biggest concern these days, some of this stuff is crazy.

And the beauty of BGA is that you can mount it on a ceramic substrate like kyocera, with embedded supply bypass caps. I used the kyocera ceramic stuff back in the late 80's, it was only available in purple. Now, I get kyocera knives...holy mackeral, are they sharp. They don't hurt even when the blade makes it to the bone.. I knew it happened, looked at my finger, said two things...one, the owner of that finger now has the name "you f'in idiot.. and two...that''s gonna hurt.

I was correct on both counts..

Originally Posted by scott wurcer

350KCM is the next step up on 4/0, probably only needed for your 1 Ohm speakers. I once looked through a battery/cable catalog for electric locomotives, the shipping will kill ya.

That's weird. I have 350 widgits being connected using 262kcmil cable, about 15 thousand feet. But the cable we are using is DLO, I guess that has different guages.

But man, you should see the subs..

j

[gpapag]

Originally Posted by SY

There's so much of the universe to explore and waiting millions of years for answers is not an attractive prospect.

On the contrary my friend. It is just because of this that the prospects are attractive. Even the probabilities are positive ( The one hand bandit hasn’t given coins for some time now).
Enjoy the flavors of one of your wines, and wait for a new burst of knowledge, like the ends of 19th century. (very romantic!)


--------------------------------------
Simon, is it you with the binoculars on the picture?

--------------------------------------

Originally Posted by jneutron

For old style chips … Home made triaxial cable.
j

Jneutron
That was disappointing. Hardly 220 words. Are you O.K. ?
Thank you (especially for the center of elipsoid part on your prior posts)

As I read it, you target the problem at the bonding wires and pads. That’s in agreement with Scott words.
This I find strange. I mean how all the routing within each layer and the stacked layers between them end up less troublesome than the bonding wires.

Originally Posted by scott wurcer

Usually an L/R/C extraction (with mutuals) from conventional methods is OK for normal IC's (100MHz or so).

Scott, I hadn’t noticed your response, sorry.

Now, to exercise your patience, one more step on the ladder:
Why these “conventional methods” brake up above say 100MHz?
Is it that the conception of L/R/C can not model the reality anymore, and if so, why?
(I guess the next floor is a few more steps higher, so prepare yourself )

Originally Posted by Positron

Not to belabor, but when...

Had you had hammered once or twice directly on the starter’s solenoid, you wouldn’t have to pray.
(Usually this activity is accompanied with shouting out some words not appropriate for a religious man)


George

[SY]

Originally Posted by Positron

Not to belabor, but when I was traveling to college way back then, one morning my car would not start, not even a solonoid click. Had 6 hours to drive.

Put jumper cables on, tried three times and not even a click, so turned key off position for 4th time. Waited a couple of minutes, prayed to God, said Amen, and heard something. Looked over and the engine was cranking like crazy. So reached inside, turned the key to on position, and engine started. No starter motor grind, problems etc. Drove to college, parked it and never tried starting it again. Sold it for 70 bucks.

This seems apropos.

Matt the Electrician "For Angela" - YouTube

[john curl]

I sure would like to know where the higher order harmonic distortion is generated, if it is not the wire-cable system, itself.
I do not know how a 'ground loop' could cause higher order harmonics distortion as of yet. Might pickup hum/noise, but harmonic distortion? And why do many cables not have much if any, higher order harmonic distortion? Yet others have it repeatedly.
Maybe it has something to do with the 'Centroid'. '-)

[Wavebourn]

John; it is higher order harmonics of 60 Hz dirt probably.