Hi Steve Eddy,
I like the buffer circuit. I wonder why it needs +/-10 and +/-20 volts. Could it be converted to only higher voltage supply with just two more resistors? I am no expert, but some here could have a look at it and tell me.
I can not even begin to believe something like this could be accomplished in today's corporate environment. I feel good that the generation I am from was the same as this group. We need more ideas like this. People actually gave of themselves to make this happen. Not just a bunch of emails and promises.
I wonder how many of the original units are still usable today?
Thanks for digging this article up and sharing.
I would not consider the BA to be an audiophile amp by today's standards! not by any means. but as a piece of history it is very cool! the back story on it alone makes it ultra cool! and it is very serviceable. well built. replace the capacitors in it and it should last a very long time. this would make an ultra cool shop bench amp kind of thing.
I work for Hewlett-Packard and I remember when those amplifiers were built. Not a well advertised effort, more of a skunk works project by the HP Labs folks in Building 20 on Page Mill Rd in Palo Alto, CA. Barney Oliver was a frickin genius. I saw one of those amps about 20 years ago.
I have a working Barney Oliver amp for sale. My father (just moved into assisted living at 86) was a project manager for HP at building #1. write to me with an offer if you are interested at [email protected]. The amp is in Redding, CA.
So is the laws of Physics flawed by modern day standards than 45 some years ago? Components only became better and more consistent. Just image what that design would be like using modern components.
I must admit that HP (and some of the other technology leading companies) employed amongst the most brilliant and innovative engineers and scientists I ever met.
Even by today's standards these designs meet or exceed any expectation and the audiophile jargon and hype was not in the engineering vocabulary of the time, only facts obtained from research and measurement.
Every parameter was not only fully understood but manually performed on an HP35 scientific calculator, another innovative idea of the time.
Just think of it, linear "audio" wide band amplifiers were designed for those days function generators that operated from 1 mHz to several MHz, produced almost any arbitrary waveform at the lowest measurable (not predicted) distortion and ultra flat response.
An FFT of a frequency sweep was done manually and could take several hours to perform. Audio is a really a walk in the park in comparison.
There existed no internet to crib someone else work from or copy and paste function to take several cribbed schematics and merge it into one or simulators that instantaneously and on the fly produced results from several stepped component values.
Designers had to actually know what they were doing - everything was original - and it took months not minutes. PCBs were designed having the net-list in your head using a light box, opaque paper, rubberized tape, stencils, etc.
Don't underestimate the designers of the past, some are still around and remain as brilliant regardless being considered Neanderthal by today's audiophiles.