From sixtiesrokker@yahoo.com Mon Feb 16 16:01:53 2004
Subject:Re: Hammon A100 and "G-G" Terminal

Hi Bob,

The A100 series uses EXACTLY the same AO-28 preamp as the B3 & C3, and
has the G-G terminals. (OK, since the preamp is mounted upside down in
the A-100, the swell pedal control is wired slightly different - can
easily be changed if an A100 preamp is moved to a B3 Or C3 or vice-versa).

The 147 was designed for organs like the A100 (with built in speakers)
and connects to the A100 speaker connections (output of the A100's
built in power amplifier) so the 147 signal is "unbalanced" and can
possibly pick up hum from motors, flourescent lights and other AC
devices on long cable runs. Hook-up kits for the 147 have provisions
for a 2nd (echo) switch for selecting between the Leslie, the A100
built-in speakers, or both. Also, since the A-100 power amp has a
certain amount of bass-boost, the 147 is a little "brighter" than the
122 to restore tonal balance (remember, the 147 connects to the output
of the bass-boosted power amp). The 147 also has a built in load
resistor to maintain the proper load on the A100's power amp when the
internal speakers are switched off. I guess you can see why the 147
is said to be "designed for" the A100.

HOWEVER.......

As you are aware, the G-G signal to the Leslie 122 is "balanced" and
less prone to pick up noise on long cable runs. And since the 122
hooks to the AO28 G-G output instead of to the bass-boosted power amp,
it doesn't have (or need) the 147's treble boost. Unfortunately, 122
interface kits don't usually provide for the "echo" switch function
(since the B3 & C3 have no power amp or speakers), BUT, a company
named Hamptone makes a 122 interface kit with the "echo" switching
function. You can order this from;

http://www.btproductions.com/
or
http://www.bborgan.com/

Hope this helps.

Jim (sixtiesrokker)