On 07/12/2015 14:53, Jim Lesurf wrote:
In article , Jim Lesurf
wrote:

If no-one can find one, I'll go to the source and ask Ortofon. They
might also find this amusing. Although sadly, 30+ years too late to
matter.

Alas, it seems that Ortofon sold off their electronics section and the
people involved retired ages ago. So this looks like being another area of
engineering history which is being forgotten and may pass undocumented if I
can't find the details somewhere! :-/

This is all the info I can find on the web:

"Basically it's a complementary common base amplifier with only two
transistors: BC485 and BC486.
The collectors are connected together and the input goes to the emitters
through 2200uF capacitors. The bases are grounded.
The output is taken from the collectors through a 22uF tantalum cap."

There are some datasheets, e.g.
http://img.aussieaudiomart.com/uploa...stepup-amp.jpg

And someone had to replace his dried-out electrolytics.

--
Eiron.