Second group is Steve Berger, Bob Danielak, Nori Komuro and John Devore.
Steve Berger of April Sound Amplifier.
For the Record, Steve's amplifier is a "two stage, PP, Ultra linear, class A,
direct coupled 7591" unit. It uses a very small amount of negative
feedback, though not to linearize it but to get the output impedance down enough to make some
bass. Steve claims it achieves a frequency response flat from 10 Hz to a 3db down point of
146 kHz! Steve has his cool side of the internet you can see by clicking
Bob Danielak's Amp
Above is none other than cool dude, and guy who
"won" a $55 packing ticket at nyNOISE, Bob
Danielak whose contribution to nyNOISE 2001 was a "Class A2" stereo
single-ended 833A amplifier seen above using ElectraPrint MT5KB (5k 30W) output transformers. The 833A's are run at 650V with zero bias for a plate current of about 100mA. The input/driver tubes are 6BM8 triode/power-pentode tubes. The triode section is direct coupled to the pentode section (triode-wired) which drives a 10:1 step-down transformer. This arrangement provides almost 80Vpp drive to the 833A grid with <20 ohm output impedance (quite important for a Class A2 amplifier).
The amplifier puts out about 15-20W per channel (which is laughable considering that each 833A filament consumes 100W -10V @ 10A!!!). I was pleasantly
surprised that this amp actually sounded pretty nice
at home and even at the show.
Spotted in the street was a true home brew tube-head's car
audio tube amplifier!
Bob dude's way cool car audio tube amplifier as seen above can be built buy DIY guys
worldwide! Please click
here to see the main schematics of his 833 amplifier. Please see all the groovy information on the tube car audio
amplifier on this
Nori Komuro's Amplifier
Click here to see
the third group of presenters PLUS auction.