Fabguy do u need a hp4062ux to test at wafer probe?
solid state vs tubes
has anyone compared a tube amp to a solid state amp and discovered that the diffference sonically between them was undetectable. ? if so what was the tube amp and what was the solid state amp ?
the reason for the question is the basic issue of the ability to distinguish a tube amp from a solid state amp.
this is especially interesting if the components were in production during the 90's , 80's or 70's.
if the components are in current production the probability of such aan occurrence might increasea.
why own a tube amp if there exists a solid state amp that sounds indistinguishable from it ?
the reason for the question is the basic issue of the ability to distinguish a tube amp from a solid state amp.
this is especially interesting if the components were in production during the 90's , 80's or 70's.
if the components are in current production the probability of such aan occurrence might increasea.
why own a tube amp if there exists a solid state amp that sounds indistinguishable from it ?
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- 180 posts total
I'm not a probe guy. i spent about 30 years making both ICs and discrete. I am most familiar with probe parametrics as they apply to my area of specialty. As for probers, I know they weren't HP. The last ones I remember were some kind of european 4 station from one central computer/data gatherer. Individual histograms of each wafer were stored for later analysis...patterns of failure and such. I avoided probe....looked too much like work. I am much more comfortable with diffusion / implant / metalization and was very good at metrology. Nanometrics equipement, surface profile stuff and elipsometer along with various 4pt probe and specialty tools. |
Magfan, here's a nice nutshell explanation that touches on this subject. That there are capacitive elements of semiconductors should not come as a surprise to anyone- most tuners these days do not rely on variable capacitors to tune the station, instead they use variactor diodes, which take advantage of this capacitive element. Literally by changing the voltage (and thus forward current) on the device the capacitance changes and is useful as a tuning cap in the RF front end of the tuner. Here's the link for the MOSFET capacitances (you can find many others on this site): http://www.diyaudio.com/forums/tubes-valves/155106-ss-followers-drive-power-tubes-3.html#post2316318 |
- 180 posts total