Drives which used an MC3470A head-amp

[Philip Pemberton]

On Sun, 2010-11-28 at 20:16 +0000, Tony Duell wrote:
> I don;t think the transistors used were that exotic. Things like 2N3904s, 
> for example.

Hmm, I wouldn't have thought they'd work at ~1MHz type speeds. They
certainly didn't work as voltage translators on a parallel-port JTAG
cable (I ended up using a TI level translator chip instead).

> The semi-0discrete solution ('74 as a divide by 2 and a handful of 
> transistors) turns up all over the place. It's easy to design and reliable.

Always nice to know. I just need to figure out how much write current
the Panasonic chip provides (all I have is a short-form datasheet, which
doesn't include any figures or calculations, just a pinout and a few
electrical specs).

> > Although whether I've got enough clearance to shove a PDIP chip in there 
> > without fouling the drive belt or flywheel is another question entirely...
> 
> Do you have to pack it into the same volume as the original drive?

I'd like to, for the sake of tidiness. It's not essential, though. Also
extending the mechanism cabling would be a bit of a pain.

-- 
Phil.
classiccmp at philpem.me.uk
http://www.philpem.me.uk/