The #1 cause of 122 Leslie's not slowing down, (speed changing), is a pitted
switching relay. When the speed is changed, there is a reverse EMF kick to
the contact points. After a few years of that, the points pit and start to
'weld' together when operating. To test this, go to slow speed and tap the
chassis of the Leslie amplifier. Better still, tap the screw mounted
through the top of the chassis which has a rubber grommet around it. This
is the speed relay. If you tap it and it does change speeds, either use
some VERY fine emery paper, (800 grit or finer), and slightly 'burnish' the
points. Then put it back into service and see how well it works. If all is
fine, that is the problem. You may want to replace BOTH of the capacitors
across the AC mains sockets to the motors as well. These are there to
weaken the EMF present on the relay. If they are bad, the spark on the
contacts will be worse. Oh yes, make sure to remove the power and let the
amp sit for a while and discharge the supply electrolytics. Any sizable
residual voltage present, would not make your day a happy one.
Also the 12AU7 tube on the left side of the chassis, is the tube used for
the relay control. They do go bad and need replacement. DO NOT substitute
with a 12AX7, the switch circuit will not function.
Bill Ziegler
Datasounds, Inc.
Check us on the web at www.datasounds.com
Let Us Build and Host Your Website
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----- Original Message -----
From: "jamesrhampton" <j.r.hampton@...>
To: <hammond_zone@...>
Sent: Wednesday, March 06, 2002 2:57 PM
Subject: [hammond_zone] Re: Leslie 122 won't slow down
Hello, Nick. The 122 supplies a dc voltage which the leslie kit
(through those half-moon switches) fires back down the audio line.
All you need do is put a switch into that line and you can control
the speed of the 122 with it. I have mounted foot switches on both X-
66 expression pedals here and can control the speed either with my
foot or with the choral/tremelo switch. BTW, if you ever find your
122 won't change speed (assuming your switches have been repaired and
are known working), this can happen because of a bad voltage
regulator in the leslie. That is the one tube that glows (is it an
OC-3? I don't have the prints in front of me). Unfortunately, I
left my digital camera over at a friend's house, but can retrieve it
if you need schematics of the leslie kit. The 122 schematics are on
the side of the amplifier chassis. Pull the amp out and the
schematic is pasted on the side of the chassis. If you need a print
of the adapter kit for the old B3s, A-100s, etc, e-mail me at
j.r.hampton@... and I will take some digital photos in
black and white (and fool with the contrast to try and make it as
readable as possible) and e-mail them to you.
Best of luck and have a gooder!
Jim Hampton
--- In hammond_zone@y..., "Nick Renich" <nrenich@b...> wrote:
G'day from Australia everybody . I arked up my gear today ( C3 /
122 ) and the Leslie won't slow down. It has fast only. My half moon
switches are obliterated by a doorway, but hopefully there is another
way to get slow speed for now until i can get new switches or fit a
push-down button which i would prefer anyway. Any ideas PLEASE? I
like fast Leslie , but not all the time. I play like Jon Lord so need
the slow very badly.By the way I played around with the control on
the expression pedal control today. I thought i had growl before,
but this is insane - and i got the info thru' the zone. Thanks
everybody. This distortion is amazing. I've had the C3 for 30 years
and was not aware of that little screw in the volume setup.
Visit The Hammond Zone
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