Hoffman Amplifiers Tube Amplifier Forum
Other Stuff => Other Topics => Topic started by: HotBluePlates on June 08, 2012, 11:17:01 pm
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Looks like HP made at least one tube stereo (http://www.ebay.com/itm/Vintage-Hewlett-Packard-HP-6K6-Stereo-Tube-Amp-Amplifier-for-Parts-/160815345144?pt=Vintage_Electronics_R2&hash=item2571576df8#ht_500wt_1287) back in the day. The tubes are probably original, and date from '67, making me think the rack case was borrowed from one of their pieces of test gear.
I know I've seen some documentation on a solid-state stereo that some of the engineers made for a small handful of employees; this may have been the precursor.
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(http://i2.photobucket.com/albums/y11/pmitchel/ttiwwp.gif)
it would be nice to have a look see at a schematic of that amp.
--DL
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The silicon amp was a project launched by the late Bernard Oliver. Check http://www.hpmemory.org/news/barney_ampl/barney_page_00.htm (http://www.hpmemory.org/news/barney_ampl/barney_page_00.htm) for more info.
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(http://i2.photobucket.com/albums/y11/pmitchel/ttiwwp.gif)
it would be nice to have a look see at a schematic of that amp.
--DL
Well, the pics are in the original fleabay listing. I figured interested parties would follow the link and check it out for themselves.
Unfortunately, a schematic would likely have to be drawn by the owner of the 6K6 stereo. And push-pull 6K6's?? I'm guessing the designer had a horn-loaded setup at home... Or at least some very efficient speakers.
The silicon amp was a project launched by the late Bernard Oliver. Check http://www.hpmemory.org/news/barney_ampl/barney_page_00.htm (http://www.hpmemory.org/news/barney_ampl/barney_page_00.htm) for more info.
Yep, the "Barney Oliver amp" was the one I was thinking of.
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P-P 6K6 is the H-P 200AB oscillator's output stage.
6V6 was available when the 200AB was designed; I never really wondered why they used the older tube.
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Good point!
But the 200AB is rated for 1w output in 600 ohms. HP did, however, use a much smaller OT in the 200AB.