BrokenHill
Well-Known Member
I have had this preamp for about two years and during that time I have searched
the Internet for information or a schematic and still cannot find anything on this pre.
So far I have replaced all the capacitors, replaced the resistors with carbon films
and changed those paper covered diodes to modern ones.
When I got the unit the volume control was extremely worn and was the only major
problem it had, I did get very lucky and found five of those concentric volume pots
in a package deal (NOS) from that auction site for a very reasonable price.
I did leave the rectifier alone although I did install a thermistor for a soft start so
hopefully the rectifier will not flip out and die, the unit use four 12AX7 tubes so
tube rolling has many options and it does respond to tube changes very nicely.
About how it sounds, it is very similar to the Eico HF-85 that I have only this thing
is dead quiet and its construction is a lot better then the Eico.
On the back their is black letter markings that read > Stedman Radio Laboratories
and thats all I know about it.
Maybe it was a prototype that never made it on the market or they are just a very
rare preamp to find.
And then maybe somebody here at AK knows all about this preamp or about the
Stedman Radio Laboratories, if not enjoy the pictures.
the Internet for information or a schematic and still cannot find anything on this pre.
So far I have replaced all the capacitors, replaced the resistors with carbon films
and changed those paper covered diodes to modern ones.
When I got the unit the volume control was extremely worn and was the only major
problem it had, I did get very lucky and found five of those concentric volume pots
in a package deal (NOS) from that auction site for a very reasonable price.
I did leave the rectifier alone although I did install a thermistor for a soft start so
hopefully the rectifier will not flip out and die, the unit use four 12AX7 tubes so
tube rolling has many options and it does respond to tube changes very nicely.
About how it sounds, it is very similar to the Eico HF-85 that I have only this thing
is dead quiet and its construction is a lot better then the Eico.
On the back their is black letter markings that read > Stedman Radio Laboratories
and thats all I know about it.
Maybe it was a prototype that never made it on the market or they are just a very
rare preamp to find.
And then maybe somebody here at AK knows all about this preamp or about the
Stedman Radio Laboratories, if not enjoy the pictures.
