During the week after I left Mikey's, he began to
disassemble my DRRI. Every day or so, Mikey sent me digital
photos of his progress. He also spent a lot of time emailing
me the exact details of what he was doing and why. These
have become a wonderful source of information for this
article. Whenever I had a question about some aspect of the
project, I'd send Mikey an email and he would patiently and
thoroughly answer my questions.
After removing the PCBs, iron, filter board, pots and jacks
from the DRRI, Mikey built a brand new filter board and
installed the Mercury iron.
In the next photo, note that the black, phenolic octal
sockets on the right that will be removed and replaced with
high-quality ceramic sockets.
Since the Mercury iron is
larger than the DRRI iron, the output transformer and choke
are slightly offset. In order to keep the output transformer
carefully away from the speaker, Mikey drilled a new hole in
the chassis to properly position the larger output
transformer.
The new filter cap board is a thing of beauty. In a quest
for the best components, Mikey chose to use something other
than the traditional Spraque Atom capacitors, although these
are similar in appearance. They are smaller but have higher
specs. For example, the Sprague 20uF caps are rated for 65
degrees centigrade whereas these can
go to 85 degrees centigrade. Their tolerances are also
tighter.
