Wurlitzer Orbit III - Out Of Tune...Help!

[j***@gmail.com]

my wurlitzer orbit III is out of tune. it went a few months without
being played, and now the entire thing is flat. is there some way to
tune it? perhaps a global tuning pot somethere or something (because
the entire thing went flat...it's in tune with itself, but it's nearly
a half step out).

thanks!

[Larry]

Post by j***@gmail.com
my wurlitzer orbit III is out of tune. it went a few months without
being played, and now the entire thing is flat. is there some way to
tune it? perhaps a global tuning pot somethere or something (because
the entire thing went flat...it's in tune with itself, but it's nearly
a half step out).
thanks!

Is it the synthesizer keyboard on top or the lower manuals? The upper
synthesizer is a totally separate unit, generator and all. Take off the
top and release the catches and the Orbit III swings up for service.
You'll find an oscillator adjustment in it...left side I think, but it's
been years.

I remember when they were new. Smartassed technicians always set them up
with that silly VFO turned wide as it would go. Anyone coming into the
store that touched an Orbit key got a loud sound that sounded like a siren
going off....great fun in a busy mall...(c;

I'll try to find the manual in my files if your lost....

[j***@gmail.com]

yeah, it's the unit with the monophonic synth on the top...and two full
sized sets of keys on the bottom and middle. it's the full sized keys
that i'm concerned with. i don't have a use for the monophonic synth on
the top. but the two sets of keys on the middle and the bottom are
flat...i'm hoping there is some master oscillator somewhere that would
allow me to nudge the thing back into proper pitch. i can't remember if
the synth on top is in tune...because i never play it...i just know
that both the middle and lower keys, and the bass pedals are all a
little flat.

i do not have to manual...perhaps that would expain it. i looked on the
net, but couldn't find one.

i really appreciate the help. thanks so much!

[Larry]

Post by j***@gmail.com
i'm hoping there is some master oscillator somewhere that would
allow me to nudge the thing back into proper pitch.

There is. You'll find a master oscillator and a specialized IC called a
"Top Octave Synthesizer" that takes the very-high-frequency oscillator and
divides it into the top octave for the divider ICs. I believe your model
has that oscillator just inside the back cover. Remove the cardboard back,
then remove 3 long woodscrews that screw into the top above the Orbit Synth
though the board over the back cover that will release the back of the top
board. Once the screws are removed, slide the board back away from the
keys and the top comes off. (If that model has key lights in the top,
unplug the plug to the lights on the top.)

The oscillator/TOS is a separate board with a couple of transistors and one
IC chip, the TOS on it. It may be screwed into the back of the organ.
There will be one adjustable coil (Hartley oscillator) and you'll need a
hex tuning tool to adjust the slug like the IF coils in an old radio.
Tuning that adjusts the whole organ's frequency.

WalMart, of all places, Electronics Department, has a fantastic Chromatic,
fully automatic tuner for $20 that has LEDs to tell you what note it hears
and 3 LEDS to tune that note flat - in tune - sharp. A great tuning device
that can also be put inline with a guitar to its amp for tuning onstage,
inline. Music dealers get $80 for similar tuners...retail.

By the way, the divider chain ICs in that thing are a pain in the ass to
change. They are soldered into a circuit board UNDER the top manual, damn
them! There are 4-legged, single-stage, divide-by-two ICs and 6 legged,
two stage, divide-by-two ICs up under there. The extra two legs are Vcc +
and - (which is grounded). The TOS feeds these little ICs under the top
manual keybed. These little ICs have a tendency to short to their rails,
which, if they are the top divider, will blow the EXPENSIVE Top Octave
Synthesizer IC output of one of the notes...or...blow the little divider IC
output that's feeding the shorted one. From any point to ground with no
key down, there should be about 2.5K ohms to ground or B+ (organ off of
course) and you check it BEFORE you solder in the replacement after you've
gotten the bad one out.....so you don't blow the new one. Just a service
note WHEN, not if, it blows a divider IC...(c;
--
Larry

Had a similar Wurlitzer with a complaint of dead pedals, a spinet, in an
old lady's house. Problem was someone had sabotaged the pedals with a
purple Duncan yoyo, putting it so the pedals wouldn't go down up inside the
pedal space. "Oh, my SON must have done that when he was 12 and I forced
him to take lessons.", she exclaimed. I asked her how old her son was,
now. "He's 45.", she said. Guess she hadn't tried to play the pedals in
many years...(c; Her son is a bigshot lawyer so he did ok, anyways....

[j***@gmail.com]

you're the man! you're efforts are very, very appreciated. i am
recording this organ this weekend, and i was going to have to pitch
shift the organ if i couldn't figure it out...and i didn't want to have
to do that. email me (jonathandowns AT gmail.com) if you'd like to hear
the track.

thanks again,
jon.

[Larry]

Post by j***@gmail.com
you're the man! you're efforts are very, very appreciated. i am
recording this organ this weekend, and i was going to have to pitch
shift the organ if i couldn't figure it out...and i didn't want to have
to do that. email me (jonathandowns AT gmail.com) if you'd like to hear
the track.
thanks again,
jon.

Glad to help, Jon. I've been in the organ repair biz since 1986. I have
about a thousand customers....who, recently, haven't had near enough
trouble with their instruments to make a decent living...(c;

What I need is a week of intense thunderstorms to blow a few power supplies
and Leslie speakers. That just hasn't happened this summer in SC. It
usually keeps me hopping.

There's still a few Lowreys and Kimballs around all corroded up, as usual.
Your Wurlitzer may have some intermittent keywires. Quick and dirty
cleaning is really easy. Press the key down and put your finger on the
plastic plunger under the keybed. Wiggle it back and forth, scraping the
wires against the collector bars until it stops crackling. Polishes 'em
right up.

You can also adjust that Wurlitzer's key switches so the keys play at the
same level as you press them down. This also corrects for some dead stops
on a key because the wires bend over time. At the back of the key is a
little adjustment screw, on top of the key behind where you'd put your
fingers to play it. This screw moves the rubber cup under the key the
plastic switch actuator sit in, up and down, adjusting the level the
actuator operates over. Adjust all of them, one note at a time, so they
start to play the notes about 1/8" from the up position. All the wires
should play all the notes by the time it goes down 1/4" or so. If one of
the switch wires is way off, bend the dead end of that wire CAREFULLY to
align it with the others. Superglue works on the plastic actuator rod if
you find one cracked, not an unusual occurance at all. The rods being a
little crooked is just normal. If they work, don't try to get them
vertical as you add to the stress and may break them.

Soldering divider ICs under the keybed is lots of fun in that WIRING MAZE
on top of them. Be careful you don't bump the soldering iron against any
wires as you unsolder and resolder the little ICs. Luckily, they are all
TTL and not static sensitive like old CMOS. THE TOP OCTAVE SYNTHESIZER IS
STATIC SENSITIVE LIKE AN OLD CLOCK IC. IT'LL BLOW IF YOU BREATHE ON
IT...and it's best left in its socket unless you just have to remove it.
They come wrapped in tin foil to protect them. All the ICs in the Orbit
are static sensitive. They're awful.

That'll give you something to chew on while you're playing around in there.
The construction of these Wurlitzers showed how cheap the company had
become. I work 'em but I hate 'em.

[jhill]

Larry -- I have a Lowery-made Story and Clark organ at the church that uses
those 4 and 6 legged divider chips. One of the 6 legged ones is bad. What
replaces them? All the ones in the circuit board have Lowery part #'s on
them.

Post by Larry

Post by j***@gmail.com
you're the man! you're efforts are very, very appreciated. i am
recording this organ this weekend, and i was going to have to pitch
shift the organ if i couldn't figure it out...and i didn't want to have
to do that. email me (jonathandowns AT gmail.com) if you'd like to hear
the track.
thanks again,
jon.

Glad to help, Jon. I've been in the organ repair biz since 1986. I have
about a thousand customers....who, recently, haven't had near enough
trouble with their instruments to make a decent living...(c;
What I need is a week of intense thunderstorms to blow a few power supplies
and Leslie speakers. That just hasn't happened this summer in SC. It
usually keeps me hopping.
There's still a few Lowreys and Kimballs around all corroded up, as usual.
Your Wurlitzer may have some intermittent keywires. Quick and dirty
cleaning is really easy. Press the key down and put your finger on the
plastic plunger under the keybed. Wiggle it back and forth, scraping the
wires against the collector bars until it stops crackling. Polishes 'em
right up.
You can also adjust that Wurlitzer's key switches so the keys play at the
same level as you press them down. This also corrects for some dead stops
on a key because the wires bend over time. At the back of the key is a
little adjustment screw, on top of the key behind where you'd put your
fingers to play it. This screw moves the rubber cup under the key the
plastic switch actuator sit in, up and down, adjusting the level the
actuator operates over. Adjust all of them, one note at a time, so they
start to play the notes about 1/8" from the up position. All the wires
should play all the notes by the time it goes down 1/4" or so. If one of
the switch wires is way off, bend the dead end of that wire CAREFULLY to
align it with the others. Superglue works on the plastic actuator rod if
you find one cracked, not an unusual occurance at all. The rods being a
little crooked is just normal. If they work, don't try to get them
vertical as you add to the stress and may break them.
Soldering divider ICs under the keybed is lots of fun in that WIRING MAZE
on top of them. Be careful you don't bump the soldering iron against any
wires as you unsolder and resolder the little ICs. Luckily, they are all
TTL and not static sensitive like old CMOS. THE TOP OCTAVE SYNTHESIZER IS
STATIC SENSITIVE LIKE AN OLD CLOCK IC. IT'LL BLOW IF YOU BREATHE ON
IT...and it's best left in its socket unless you just have to remove it.
They come wrapped in tin foil to protect them. All the ICs in the Orbit
are static sensitive. They're awful.
That'll give you something to chew on while you're playing around in there.
The construction of these Wurlitzers showed how cheap the company had
become. I work 'em but I hate 'em.
--
Larry
Gotta go....A Kimball monstrosity awaits me...(c;

[Larry]

Post by jhill
Larry -- I have a Lowery-made Story and Clark organ at the church that
uses those 4 and 6 legged divider chips. One of the 6 legged ones is
bad. What replaces them? All the ones in the circuit board have
Lowery part #'s on them.

Organ Service Corp has all your Lowrey parts, now that the other company
who controlled them has gone belly up out west. Organ Service Corp is
great people. Just call the Lowrey numbers in or buy them right online.

http://www.organservice.com/lowrey/Lowrey.htm

I've been a customer since 1986. Sure wish they all were as easy as OSC to
buy from...(snif)

Kimball also used these ICs for whole series of organs....They are all
interchangeable and have the same pin configuration.