Looking for chip info on an extinct Harris op-amp

[Mark Hammer]

A buddy with an old MCI board (IIRC it was Leon Russell's mobile unit) needs some information on an older Harris op-amp.  We have both searched in vain but found nothing on-line.  Links, scans or even hunches are all welcome at this point.

The device in question is an HA-911.  Its internal designation was MCI 2001.  Whatever help you can provide will be appreciated.

Thanks,
Mark

[Vsat]

Mark,
I've looked for info on the HA911 as well, and found very little. It was used in the old 1972-vintage Countryman phaser. Little white ceramic flatpacks, HA911-5.

Apparently this was one of the better quality op amps for audio use at the time. I might have a scan of an old magazine article showing a preamp based on this chip, will take a look. Lacking an old Harris databook, first edition of W. Jung's Op Amp Cookbook might have something to say on it.
Regards, Mike

[MR COFFEE]

Hi Mark,

It's an oldie from the 70's  <grin>

It's a single low noise 7nv/hz internally-compensated op amp in a 14-pin flat pack or 8-lead TO-99. It is made on a dielectrically-isolated process developed by Harris for high performance and can even run off +-20v supplies. The 14-pin package also has a bias control on pin 8.
20 ma output current. 2mv offset voltage. It's all bipolar, slew rate assymetical at +5, -2 V per microsecond. 7 mhz bandwidth, 20 khz power bandwidth, which was pretty good for those days. Does +- 10v output swing on +- 15volt supplies. Standard pinout on the TO-99.

That about covers it.

[Mark Hammer]

Thanks, gentlemen.  I'll relay that info.  Anything else anyone can dredge up is probably appreciated.  Mike, I have that Walter Jung book.  I should dig through it when I get home.

You mention of the Countryman phaser reminded me: have you seen the interior shots of the Castle Phaser at Modezero?  That's a whole lotta 3080's.

[Vsat]

Mark,
I have a pdf here, entitled "Microphone preamp gets power through the signal cable". Shows circuit for HA911. It was originally published in Electronics, and was downloaded from one of the circuit compendia websites that has a bunch of scans from EDN and Electronics and Electronic Design.(don't remember which, maybe All About Circuits?... it was listed under Preamps).
Regards, Mike

[BDuguay]

I might be able to help. As described, those chips sound like the same ones a buddy of mine needed to fix his old Yamaha console. I think he found a source. I'll check it out and let you know.
B.

[Vsat]

Mark,
I just emailed the preamp pdf to your .psc address. Hopefully it shows up.
Mike