Hammond X77 Owners Corner

[bnelson218]

Hi,
Do you still have any X77 parts laying about?
Bruce

[Tigfit]

I found out they while changing the tabs on the Organ in the positions you recommended that when I went back to main down and Echo up that if I wiggled the tab a little the distorted static sound will disappear. Can the tabs be cleaned with Deoxit or will it hurt them. If I play the Organ a bit the static returns then moving the switch a bit it will make it disappear again! Keys Sound nice without static sound

This means that the noise is originating in the organ, not the Leslie. Your next challenge is to identify the channel the noise is on. You're going to need a service manual.

[Admin]

Yes, cleaning the contacts with DeOxit would be a good idea.

[Tigfit]

Cleaned a lot of plugs and tab switches with Deoxit like your suggestion on another link in the form and now I have percussion and reiteration back ! It was a surprise to me when I went back to working on it last night. Still think I am going to have to get in to the foot pedal section of the organ because it was in a Garage and had plenty of dirt & leaves were the felt pads are over the switches! Vacuum as much as I could but they still sound very fuzzy. By cleaning the tabs it took care of the Static sound . Now with no static sound I can hear hum in the Leslie when no keys are being played. Is it a good Idea to spray deoxit and maybe clean all the single termination plugs that attach to all the circuit boards or is that asking for trouble .

[Tigfit]

Can anyone tell me what this socket with I think a resistor screwed into the socket which is hooked in parallel with the power to the rhythm II Box.

[Donb]

So...........where can we find the actual mods Don? Thanks, another Don

[jkrusel]

It's a "Damp Chaser", just a small resistance heater, about 25-40 watts or so, used to keep everything nice and warm in locations where the humidity tends to be high or temperature swings occur like in a big old church.

[Tigfit]

Thanks for the info! I never seen one of these before. Guess a good thing to have since the Organ has been in Florida!

It's a "Damp Chaser", just a small resistance heater, about 25-40 watts or so, used to keep everything nice and warm in locations where the humidity tends to be high or temperature swings occur like in a big old church.

[Guest]

So, I acquired an X77 (no Leslie). The previous owner had modified the wiring to adapt the output to a nine pin Leslie connector box 016352 and totally bypassing the original 129-000001 Outlet Box with the two 11 pin Leslie sockets. I am looking for an X77 Leslie, but in the meantime, I would like to restore the connections to the original Outlet Box, as well as send output to a Leslie connector box 26-1 to connect to an old Leslie 125 I have laying around. My problem is I can't identify the pinout of the P471 plug coming from the Control Panel, which presumably was originally connected to the original Outlet Box. The schematics for the X77 Organ show two things connecting to the Outlet box: 1. a bundle of 12 wires from the Control Panel, and 2. two power wires. But there is no schematic for the Outlet Box. My question, then, is what wires connect where and what do they do?

Red, Orange, Yellow, Green
Black, White with Blue, Blue, Purple
White with Green, White Yellow, White with Orange, White with Red

Any help or suggestions would be greatly appreciated.

[bnelson218]

Well, my X77-B is tucked away and the rebuild project is on hold for the winter. I've got time now to go over all the modifications and effects I hope to install and am wondering if anyone has had any experience with adding a Trek II preamp (SSP-3) to an X77? I definitely want to add B3 style vibrato and already have the scanner and linebox in place. So, aside from getting rid of all the unreliable and noisy solid state electronics inherent to an X77, the SSP-3 will provide the drive and recovery circuits for the vibrato. I'm anxious to hear it. Has anyone gone this route and willing to share the results with me? I'd appreciate it. If anyone's interested there are pictures of the project under the Hammond forum and I'm going to ask the administrator if there's any way to move that thread under here.
Bruce

[bnelson218]

The wiring for the output sockets should be covered on the main schematic, though it won't show the outlet box, pursey. I believe the solid colored wires are the signal feeds (vibrato, non-vibrato, bass, and percussion) from the 'main' tab switch to the 'main' socket, and the stripped wires are from the 'echo' tab switch (although I might have this reversed, sorry). Additional wires would naturally include ground and rotor control plus the 18 guage blue and gray AC wires. For the 125 you'll need to find the vibrato signal (assuming that's what you want to send to the Leslie) and a ground line. You'll need to install a seperate switch for the motor control (or a relay operated off the existing control). I'm pretty sure the signal lines are red (NVib), yello (Vib), Orange (bass) and green (perc), but again I may be wrong as my own X77 has been totally rebuilt to where this wiring doesn't even exist anymore. With a small amplifier you can easily trace which line is carrying which signal.

So, I acquired an X77 (no Leslie). The previous owner had modified the wiring to adapt the output to a nine pin Leslie connector box 016352 and totally bypassing the original 129-000001 Outlet Box with the two 11 pin Leslie sockets. I am looking for an X77 Leslie, but in the meantime, I would like to restore the connections to the original Outlet Box, as well as send output to a Leslie connector box 26-1 to connect to an old Leslie 125 I have laying around. My problem is I can't identify the pinout of the P471 plug coming from the Control Panel, which presumably was originally connected to the original Outlet Box. The schematics for the X77 Organ show two things connecting to the Outlet box: 1. a bundle of 12 wires from the Control Panel, and 2. two power wires. But there is no schematic for the Outlet Box. My question, then, is what wires connect where and what do they do?

Red, Orange, Yellow, Green
Black, White with Blue, Blue, Purple
White with Green, White Yellow, White with Orange, White with Red

Any help or suggestions would be greatly appreciated.

[indianajo]

If you, nelson218 are good enough at laying out circuit boards you can lay out a Lowrey AOC circuit, I wonder why you would want to buy a trek amp for the x77. A couple of op amps and some mixer resistors on the input, you're up to 1.6 vac which is the input voltage of a power amp. You do have to figure out which amp outputs have to go to which switching tabs, but you'd have to do that with a trek anyway. the problems with the X77 first edition were wiring harness instead of the transistors anyway. If you put a trek in it is going to need a new wiring harness to keep the tab switches working, so you don't get out of that onerous job buy buying a packaged preamp. Driving the vib scanner and stereo vib outputs (if any) is going to be TBD anyway since the Trek is a device for a monaural organ.

[bnelson218]

If you, nelson218 are good enough at laying out circuit boards you can lay out a Lowrey AOC circuit, I wonder why you would want to buy a trek amp for the x77. A couple of op amps and some mixer resistors on the input, you're up to 1.6 vac which is the input voltage of a power amp. You do have to figure out which amp outputs have to go to which switching tabs, but you'd have to do that with a trek anyway. the problems with the X77 first edition were wiring harness instead of the transistors anyway. If you put a trek in it is going to need a new wiring harness to keep the tab switches working, so you don't get out of that onerous job buy buying a packaged preamp. Driving the vib scanner and stereo vib outputs (if any) is going to be TBD anyway since the Trek is a device for a monaural organ.

Well, I'm by no means an engineer. I've serviced electronics long enough to have a good working idea of what does what, but to sit down and try and figure resistance loads and impedances, which is necessary to design preamp stages from scratch, I'd be lost.
I dislike the stop tabs Hammond used in their organs. They are hard to access, and from a field service perspective, the time spent trying to figure out their pole vs wiper array in the event of a broken contact, is ridiculous. I actually scrapped the entire control panel for my X77-B rebuild and designed a new one.

It made sense to do this since all the electronics are being changed out.
I have added B3-style vibrato with the addition of a scanner and linebox which the Trek II SSP-3 can drive without issue.
I'm not sure what 'TDB' means... :) Yes, the rebuild keeps the organ as a monural instrument. The output of the SSP-3 wires directly to the rotor channel, but I have also added a "mains" channel (speakers without any type of tremulant) and a bass channel.
Additonally, the percussion section has been enhanced to offer 8 drawbar footages plus a "slow" effect. The Chord Comp (AOC) will simply appear to the organ as another drawbar voice and route to the rotor channel. The lower manual strings (also available thru the existing arpeggio bar), along with the internal synthesizer, are directed to the mains channel.
All in all, I have simply added/changed too much to the instrument to have retained the old control panel. I've used all available cheek block area for various controls.
If I had the knowledge to do so I would build my own preamping system and save the 400 or 500 I'll spend on the SSP-3, but I don't, and after investing what I have to date, I really want this organ to work perfectly and sound great. And aside from the well-matched circuitry of the Trek II preamp, there are other factors I have to consider, such as the built-in percussion and reverb system. Also, I'll need the 2 optional auxiliary preamps and want all of this governed by the SSP-3's voltage-controlled expression system. And, after devising a way to mount the 17 added circuit boards, I don't have the room for anything else. :o

[mpeets]

Thanks for identifying the main signal lines, i.e. red, yellow, orange, green. Those were all I needed to route all the sound out. What I did was solder in four guitar cords to run the red, yellow, orange, green, with common black grounds out to a small four channel mini-mixer. Then I ran the out from the mini-mixer to my old Leslie through my old 26-1 connector box which also has the half moon switch connected. Using the mini-mixer EQ and Volume sliders adjusts the sound to be awesome. The downfall of all this is that the X-77 console has no vibrato, relying on the vibrato provided in the X-77 Leslie which I as yet don't have. Must be a way to add a vibrato board to the console. Looking into that. What I still need to do, though, is to figure out the pin-out for the other eight striped wires that used to go to original connector box so I can restore the wiring to the two eleven-pin female connectors for when I find an X-77 Leslie. At this point I don't really care what the striped wires do, but surely someone somewhere can tell me which wires go to which pin on the female Leslie connectors in the original connector box. There are twelve wires coming from the console plug. Add to that the two power wires that come from a different plug on a transformer board destined for the Leslie. That makes fourteen wires, and really only eleven available pins on the Leslie connector. Ugh.

[bnelson218]

Thanks for identifying the main signal lines, i.e. red, yellow, orange, green. Those were all I needed to route all the sound out. What I did was solder in four guitar cords to run the red, yellow, orange, green, with common black grounds out to a small four channel mini-mixer. Then I ran the out from the mini-mixer to my old Leslie through my old 26-1 connector box which also has the half moon switch connected. Using the mini-mixer EQ and Volume sliders adjusts the sound to be awesome. The downfall of all this is that the X-77 console has no vibrato, relying on the vibrato provided in the X-77 Leslie which I as yet don't have. Must be a way to add a vibrato board to the console. Looking into that. What I still need to do, though, is to figure out the pin-out for the other eight striped wires that used to go to original connector box so I can restore the wiring to the two eleven-pin female connectors for when I find an X-77 Leslie. At this point I don't really care what the striped wires do, but surely someone somewhere can tell me which wires go to which pin on the female Leslie connectors in the original connector box. There are twelve wires coming from the console plug. Add to that the two power wires that come from a different plug on a transformer board destined for the Leslie. That makes fourteen wires, and really only eleven available pins on the Leslie connector. Ugh.

Hi Mpeets. I believe the solid wires are the MAIN output and the stripped the ECHO, or maybe it's visa-versa. It'd be a simple matter to trace these with a small guitar amp. I bought one form just this purpose on ebay for 14 bucks. It even looks like a little fender amp. And I wouldn't worry about acquiring an actual X77 Leslie either. The thing was an abomination. I built my own and also bought a ported 15" cabinet for the bass channel, and a smaller cabinet for the main channel which has a 10" speaker and a horn. The organ has an active crossover built in which will drive a 2-channel power amp that will inturn drive the Leslie's horn and bass speaker. There's an additional power amp that will drive the bass and main cabinet. The amps are rack mounted versions and will sit on top of the Leslie. Honestly, if I were you I'd look for a 147 or 725, one of the single-ended input Leslies, and keep it simple (and stay away from any model with the spinning 6By9 speaker). For the bass I'd do a seperate cabinet. They're cheap and available from shops that make the enclosures for car installs. That's where I got mine and then loaded it with an Eminence 15" speaker.

The Hammond vibrato/chorus effect is something I dearly wanted to add to the X77. The X's tone generator has the mounting holes for a scanner at the right end (facing the back). Additionally, the generator's drive shaft is accessable here to drive the scanner. I looked at various models in hopes to find the appropriate scanner, pictured here:


As you can see it has the mouting plate attached to it which, in turn, bolts to the end of the X's generator. I found this one on Ebay and I believe it came from an E-100. Here's the linebox I acquired from the same seller, likely also from an E-100 although it might also be from an A-100:


Another consideration was the V1, C1, V2, C2, etc, selector switch. I don't have the room under the drawbar rail to install one of these, nor did I want to take the time to design an analog or digital version, so I decided to just wire the linebox and scanner in the V3/C3 mode, which is what I use all the time anyway. I also added a 50K pot so I could have adjustable chorus. Here's the schematic that shows the wiring for this between the linebox and scanner:


At this point I intend to install a Trek II SSP-3 preamp to handle the drive and recovery of the vibrato signal. This is the 2nd rebuld of my X77-B. For the first one I only replaced various caps and transistors in hopes it would improve the organ's sound, but the X was plagued with so many noisy and poorly designed circuits that I ended up gutting it and starting from scratch. At this point, the only original items are the manuals and the generator. If I can help more please let me know. You can also email me at bnelson218@yahoo.com.
Bruce

- - - Updated - - -

Thanks for identifying the main signal lines, i.e. red, yellow, orange, green. Those were all I needed to route all the sound out. What I did was solder in four guitar cords to run the red, yellow, orange, green, with common black grounds out to a small four channel mini-mixer. Then I ran the out from the mini-mixer to my old Leslie through my old 26-1 connector box which also has the half moon switch connected. Using the mini-mixer EQ and Volume sliders adjusts the sound to be awesome. The downfall of all this is that the X-77 console has no vibrato, relying on the vibrato provided in the X-77 Leslie which I as yet don't have. Must be a way to add a vibrato board to the console. Looking into that. What I still need to do, though, is to figure out the pin-out for the other eight striped wires that used to go to original connector box so I can restore the wiring to the two eleven-pin female connectors for when I find an X-77 Leslie. At this point I don't really care what the striped wires do, but surely someone somewhere can tell me which wires go to which pin on the female Leslie connectors in the original connector box. There are twelve wires coming from the console plug. Add to that the two power wires that come from a different plug on a transformer board destined for the Leslie. That makes fourteen wires, and really only eleven available pins on the Leslie connector. Ugh.

Hi Mpeets. I believe the solid wires are the MAIN output and the stripped the ECHO, or maybe it's visa-versa. It'd be a simple matter to trace these with a small guitar amp. I bought one form just this purpose on ebay for 14 bucks. It even looks like a little fender amp. And I wouldn't worry about acquiring an actual X77 Leslie either. The thing was an abomination. I built my own and also bought a ported 15" cabinet for the bass channel, and a smaller cabinet for the main channel which has a 10" speaker and a horn. The organ has an active crossover built in which will drive a 2-channel power amp that will inturn drive the Leslie's horn and bass speaker. There's an additional power amp that will drive the bass and main cabinet. The amps are rack mounted versions and will sit on top of the Leslie. Honestly, if I were you I'd look for a 147 or 725, one of the single-ended input Leslies, and keep it simple (and stay away from any model with the spinning 6By9 speaker). For the bass I'd do a seperate cabinet. They're cheap and available from shops that make the enclosures for car installs. That's where I got mine and then loaded it with an Eminence 15" speaker.

The Hammond vibrato/chorus effect is something I dearly wanted to add to the X77. The X's tone generator has the mounting holes for a scanner at the right end (facing the back). Additionally, the generator's drive shaft is accessable here to drive the scanner. I looked at various models in hopes to find the appropriate scanner, pictured here:


As you can see it has the mouting plate attached to it which, in turn, bolts to the end of the X's generator. I found this one on Ebay and I believe it came from an E-100. Here's the linebox I acquired from the same seller, likely also from an E-100 although it might also be from an A-100:


Another consideration was the V1, C1, V2, C2, etc, selector switch. I don't have the room under the drawbar rail to install one of these, nor did I want to take the time to design an analog or digital version, so I decided to just wire the linebox and scanner in the V3/C3 mode, which is what I use all the time anyway. I also added a 50K pot so I could have adjustable chorus. Here's the schematic that shows the wiring for this between the linebox and scanner:


At this point I intend to install a Trek II SSP-3 preamp to handle the drive and recovery of the vibrato signal. This is the 2nd rebuld of my X77-B. For the first one I only replaced various caps and transistors in hopes it would improve the organ's sound, but the X was plagued with so many noisy and poorly designed circuits that I ended up gutting it and starting from scratch. At this point, the only original items are the manuals and the generator. If I can help more please let me know. You can also email me at bnelson218@yahoo.com.
Bruce