Barney Oliver intergrated amp. - negative feedback design

D

DaveyainJH

New Member
Hello, my first posting here. Have a complete, clean example of this limited production unit. Have read some info. and contacted HP's curator Mr. Kuhn concerning selling it. Any thoughts on the negative feedback design? I listen to music constantly but am not an electrical expert.
 
This was a very special amp, produced at the Santa Clara Instrument Division of HP as a G-job. A G-job was an unauthorized project (also known as a skunkworks project) but involved a very active audiophile, Barney Oliver, who happened to be the head of HP Labs (HP's think tank).

If you're interested, there's more here on the details.

As for the negative feedback design, post a schematic if you can find one. What's the interest in that detail, exactly?

Cheers,

David
 
I followed the link above, very interesting story. Look at the size of the volume attenuator, it's a stepped attenuator and I'm sure it's a work of art. HP test gear from that era is incredibly well built.
I wish they had branched off into HiFi gear. They would have been a major competitor with the likes of McIntosh.
Not much chance of ever finding one of these, a shame.

BillWojo
 
BillWojo said:
I followed the link above, very interesting story. Look at the size of the volume attenuator, it's a stepped attenuator and I'm sure it's a work of art. HP test gear from that era is incredibly well built.
I wish they had branched off into HiFi gear. They would have been a major competitor with the likes of McIntosh.
Not much chance of ever finding one of these, a shame.

BillWojo
Click to expand...

I found one on CL a couple years ago...
It sounds wonderful with my JBL 4311Bs and a Shure V-15 cart... I do have to crank the gain to 80% for substantial volume though... I don't mind.
I wish I had some L15s, I need to try it out on some of the Klipsch...hmm
 
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DaveyainJH said:
Hello, my first posting here. Have a complete, clean example of this limited production unit. Have read some info. and contacted HP's curator Mr. Kuhn concerning selling it. Any thoughts on the negative feedback design? I listen to music constantly but am not an electrical expert.
Click to expand...

What is the serial #?
 
DaveyainJH said:
Hello, my first posting here. Have a complete, clean example of this limited production unit. Have read some info. and contacted HP's curator Mr. Kuhn concerning selling it. Any thoughts on the negative feedback design? I listen to music constantly but am not an electrical expert.
Click to expand...

You should buy a membership here for $25 and list it in Bartertown.
 
A bit of the Barney Oliver story.
I was present for the unvailing and demoing of the B O amp by Mr. Barney Oliver him self at the HP hdqtrs
auditorium in Palo Alto ca. He was director of HP labs and was a formidible person in stature. Big guy.
The Barney Oliver amp was designed by B O and tuned to match the shure v15II cart input Z precisly by Barney. .
and used a stepped attenuator given to B by a mil contractor as a eval sample. it was very expensive. Barney had the power. The amp was built around it. And because of it.
the amp was 50wpc and used full complementary symetry output design and used 2n3055 output transistors.
HP used em by the trukload.
Only tone was a bass switch for abit of boost. The amp gave a great performance. Music was The 4 Seasons by Vivaldi.
Speakers were some big JBLs up on stage and a TT (?make) with a shure V15II cart. installed.
the amp was built and tested at HP Santa Clara, Ca Freq. and Time devision which was my home devision
and I was priviledged to see the whole process unfold as they were made and tested. I remember seeing dozens sitting around the assembly/test floor. One of the BO test techs was a co-worker and we talked alot about the amp.
I did not buy one however at $350 each. I had other gear to play with at the time.
The BO amp is today more of a legend than a super wonderful amp. Many other amps outdid it it in maany respects. But it was no slouch.
Still it was quite a conversation piece amongst those HP employees who bought them. And they were completely sold out.
You had to fill in a "I wil buy one" card at the demo and be put on the list to get one.
Just thought some of U mite like to hear abit of history.
PS: The B O amp was completely authorized and approved by HP.
Nothing underhanded or G-job about it.
 
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sheltie dave said:
http://manualslibrary.net/BARNEY-OLIVER-AMPLIFIER-MANUAL-REPAIR.html

http://www.ebay.com/itm/Barney-Oliv...427553?hash=item3f6e893d61:g:sYEAAOSwzaJYArtD
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That link to the repair manual calls for a Credit Card to verify registration.

First I have seen that, and a limitation I am not comfortable with. I'd be curious if anyone has actually used this website?

I have a prototype amp which paralleled the BO amp given to me by a retired HP Tech which needs a minor service.

My amp started out as a different amp design : when the original outputs kept blowing the builder replaced the main boards with BO boards which he had access to.

It's an ugly amp, even by AK standards, but it is, in essence a BO amp and the repair manual for a BO amp should be good enough for this one.
 
ferninando said:
brings back some powerful memorys. Those were the days.
glad U liked it.
Click to expand...
Yes!
Thank you very much!
I have read about a "open cage" policy at HP in those days... Is it true that an employee had free reign around the spare parts and could build anything they desired?
 
Yes biscuithead, its tru.
Guys built counters, clocks, amps from Pop.Elect. mags., nixie clocks. Later LED dislays were popular.
In fact One tech who I mentioned in the BO bit managed to get autthorization from HP to build a small run of
of the "Brute 70" amp from Pop Elect..A 70watt SS amp of superb performance. All from Hp parts, sheet metal, HP made PC boards and the whole works.
He was also resonsible for a run of Bose 901s when they cam out. Lotta guys got em. me included. Eq and all.
Guys even built some of the HP production equipment as personal projects, like freq counters which were the divisions charter products.
Mostly 1/4 rack 6 digit types, with nixie tubes. Just rite for a home tech bench.
The upstairs engineering LAB stock was also frequently utilized. We could get parts from open bins used by the design engineers.
This all began for me in 1969 when I was hired as a test tech on the counter prod. line for turn-on and final test.
Those were indeed the good old days.
HP is no longer the same company.

PS: 1 more bit. I retired in 99 after 30 yrs. at HP.
The lead tech that hired me had Mac gear amp and pream, thorens 124 TTw/SME arm and shure V15II
and JBL Olympus speakers. Pretty standard fare for the hard core audiohead of the time.
The lead on another line had about the same and I ended up with his homebuilt JBL Olympus spkrs,
Mac C26 pre, Brute 70 amp, thorens tt plus some other stuff, to help pay for his divorce. All for $1400. A real steal for all that stuff. Boy was I a happy camper.
I dont think the BO amp was bad looking. All a matter of taste I gess.
 
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Glad to know you were there, Ferninando. I was a Field Engineer on the East Coast with HP and heard of the BO amp as a matter of lore - never saw or heard one. We didn't get the percs that the factory-dweebs got - well maybe the car and expense account worked to our favor. I married an HP Labs gal and moved to the Bay Area 20 years ago then retired after 20 years in 2005. It was a great ride!

Cheers,

David (HP retired 1984 - 2005)
 
HP sounded a lot like the BBC in its heyday, the LS3/5a followed a similar developmental path nd was built in house by their own carpentry department and then equipment department. An exBBC employee started Chartwell speakers and the Project Symphony was an LS3/5a kit essentially which many times was calibrated by BBC techs.
 
ferninando said:
Yes biscuithead, its tru.
Guys built counters, clocks, amps from Pop.Elect. mags., nixie clocks. Later LED dislays were popular.
In fact One tech who I mentioned in the BO bit managed to get autthorization from HP to build a small run of
of the "Brute 70" amp from Pop Elect..A 70watt SS amp of superb performance. All from Hp parts, sheet metal, HP made PC boards and the whole works.
He was also resonsible for a run of Bose 901s when they cam out. Lotta guys got em. me included. Eq and all.
Guys even built some of the HP production equipment as personal projects, like freq counters which were the divisions charter products.
Mostly 1/4 rack 6 digit types, with nixie tubes. Just rite for a home tech bench.
The upstairs engineering LAB stock was also frequently utilized. We could get parts from open bins used by the design engineers.
This all began for me in 1969 when I was hired as a test tech on the counter prod. line for turn-on and final test.
Those were indeed the good old days.
HP is no longer the same company.

PS: 1 more bit. I retired in 99 after 30 yrs. at HP.
The lead tech that hired me had Mac gear amp and pream, thorens 124 TTw/SME arm and shure V15II
and JBL Olympus speakers. Pretty standard fare for the hard core audiohead of the time.
The lead on another line had about the same and I ended up with his homebuilt JBL Olympus spkrs,
Mac C26 pre, Brute 70 amp, thorens tt plus some other stuff, to help pay for his divorce. All for $1400. A real steal for all that stuff. Boy was I a happy camper.
I dont think the BO amp was bad looking. All a matter of taste I gess.
Click to expand...

WOW.
Very cool my friend!
What a thing of the past... a business model like that.
I have done outside contracting for some of those 60s-70s manufacturing giants: HP, Woodward, Kodak... They are unrecognizable as the pinnacles they once were. Corporate initiatives sure have changed in 40-50 years, but record profits are still posted.

You were present for the most "healthy" times of Manufacturing employment in the U.S. I am Jealous!

Thanks for sharing your memories!

P.S. Want to double your money on that $1400 deal ? ;)
 
Well biscuit, its all gone now.
I gave the brute 70 to my tech friend co-worker who built the run as his wife screwed him in divorce and got it .
the Mac c26 and JBL Olympus spkrs I kept for the duration but sold some yrs ago and I got some profit from the sales..
Best of times IMO.
Before all mfg. went to china.
Sad to say hp was among the 1st to send a product to china to build and I was working with/on it the product whan it happened.
The 5045 IC tester.

PS: I have not seen any of the guys I worked with at HP here on AK. No clue why.
Am I the only one remaining?
 
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