Tonewheel Organ Newbie, Considering Hammond BV

[SunwoodRecording]

Hi There Y'all, this is my first OrganForum post :->

I have a line on a Hammond BV that is described as 'needs woodwork' (I can see in the provided image the rear of the chassis is open, and whatever covers the drawbar mechanism is either open or removed). I can deal with this, being proficient at woodworking. I'm looking for an organ to be used in a recording studio setting, so cosmetics/collectibility aren't necessarily a consideration... tone is. This organ is $300. It doesn't come with a tone cabinet, as far as I know, nor do I know whether it even powers on. I will get a chance to inspect/test it before I commit to purchase, however.

Is this a good deal? I've had an eye out for something B3-esque for a while, so I don't mind spending on a Leslie if I can get a good deal on an organ. I also don't know the first thing about how this BV would connect to any sort of amplifier/cabinet/leslie. (line out? preamp out? rca/phono plugs/6-pin cable?) Please advise!

I also don't mind rooting around with a multimeter and doing basic soldering/component-replacement.

Thank you for your help!

[muckelroy]

It comes down to location, but I can't think of any location where $300 is a "bad deal" for even a beat down BV, unless the cabinet is absolutely completely trashed. And "trashed" has many meanings depending on your woodworking skill.

You'll spend much more than $300 fixing it up to have it "studio" worthy, though. Assuming the generator doesn't have any bad bearings and can be brought back to life with a good oiling, you will need to have the preamp gone through and serviced, as it's around 70 years old.

You'll want to clean the bus bars, keybeds, lube the preset key mechanism. This type of work is best done with the manuals removed completely from the organ. Worst case, your bus bars are trashed, or you have bad key contacts, which will necessitate you to find replacement bus bars and/or donor key contacts where needed.

All BVs have ratcheting-type drawbars, unless they were upgraded by someone along the way. Most players in a recording studio will cringe at ratcheting drawbars. Keep this in mind. You'll want to have a budget for replacing the drawbar assembly with a donor smooth set.

If you add percussion, it's a lot like a B3, minus the selective vibrato, if your studio clients are OK with that.

[muckelroy]

A few more points...

1. Open back storage - there is probably lots of dust and other debris (rodents, bug carcasses, etc). You'll want to gut the thing and do a thorough clean-out of the generator
2. Music rack missing means that the chorus/vibrato toggle switch may also be missing, as that is where the chorus / vibrato switch was mounted. It will take some thought and consideration to replace this switch. It will be much easier to find a donor music rack and vib/chorus switch than to make these things from scratch. I could be wrong but I think the CV and BV share the same music rack. Grain of salt on that info.
3. The preamp needs B+ (about 200V DC) power to operate. It steals this from a connected Hammond tone cabinet. By default the preamp is wired to the output socket with a 6 pin female connector on the outlet box.
-- If you don't want to use a Hammond tone cabinet, the best choice is a Leslie 122 or similar 6H type Leslie so that it can send its B+ voltage to the preamp. You need a kit for this to work properly with Tremolo switching.
-- You can also install a small independent B+ power supply inside the organ so that the organ is not a "slave" to any connected tone cab or Leslie for the preamp to operate.

4. Line out: You can construct a line out if you wish. It can be either balanced or unbalanced, you choice.

5. Leslies, the leslie 147 type amplifiers (6W) don't need a kit, but you do need a half moon switch or some way to switch speeds. (remember that if you ONLY buy a Leslie 147, you'll want to install an independent B+ power supply inside the organ. 147 type amps do not send B+ to the organ.)
-- If you want to use a 6H type Leslie (122 type) you do need a tremolo kit, as it's a different hookup scheme.

[SunwoodRecording]

A few more points...

1. Open back storage - there is probably lots of dust and other debris (rodents, bug carcasses, etc). You'll want to gut the thing and do a thorough clean-out of the generator
2. Music rack missing means that the chorus/vibrato toggle switch may also be missing, as that is where the chorus / vibrato switch was mounted. It will take some thought and consideration to replace this switch. It will be much easier to find a donor music rack and vib/chorus switch than to make these things from scratch. I could be wrong but I think the CV and BV share the same music rack. Grain of salt on that info.
3. The preamp needs B+ (about 200V DC) power to operate. It steals this from a connected Hammond tone cabinet. By default the preamp is wired to the output socket with a 6 pin female connector on the outlet box.
-- If you don't want to use a Hammond tone cabinet, the best choice is a Leslie 122 or similar 6H type Leslie so that it can send its B+ voltage to the preamp. You need a kit for this to work properly with Tremolo switching.
-- You can also install a small independent B+ power supply inside the organ so that the organ is not a "slave" to any connected tone cab or Leslie for the preamp to operate.

4. Line out: You can construct a line out if you wish. It can be either balanced or unbalanced, you choice.

5. Leslies, the leslie 147 type amplifiers (6W) don't need a kit, but you do need a half moon switch or some way to switch speeds. (remember that if you ONLY buy a Leslie 147, you'll want to install an independent B+ power supply inside the organ. 147 type amps do not send B+ to the organ.)
-- If you want to use a 6H type Leslie (122 type) you do need a tremolo kit, as it's a different hookup scheme.

WOWZA, THANK YOU SO MUCH for all this information; were I in Texas I'd buy you a six-pack :) I've decided to get this organ and will update this thread with pics and progress. I really appreciate the time and thought you've given to fill me in about this endeavor. Cheers!

[NittyRanks]

Let us know how you make out.

[SunwoodRecording]

So I bought it :D The music rack is included, which is good. There are no foot pedals, but the electronics are there for them. Apparently it was used by a soul band in the 60s, and instead of putting it on casters, they lugged it around each gig, so the cabinet is in rough shape. I'm bummed that the seller sold the 122 leslie years ago. I'll post some pictures soon. My first task is reenforcing where the legs meet the case & replacing the feet-bottoms with casters. That'll make it easier to wheel around the shop. Also ordering some hammond oil.

Without a tone cabinet, what do you reckon is the best way to test it out electrically? A B+ power kit and a line out? I'm selling some gear soon that will enable me to purchase a leslie, but It'd be nice to know what I'm up against with the internals of the BV before I take the leslie plunge...

[muckelroy]

Without a tone cabinet, what do you reckon is the best way to test it out electrically? A B+ power kit and a line out? I'm selling some gear soon that will enable me to purchase a leslie, but It'd be nice to know what I'm up against with the internals of the BV before I take the leslie plunge...

You'd be best served using a small B+ power supply. Tonewheel General sells one that works nicely. But honestly, don't do that yet. Assume the preamp will need to be completely gone through and serviced before applying AC power to it, or B+ power to it.

The bigger question is how good of shape the generator is in. Give it a hefty dose of naphtha followed by a dose of Hammond oil. Put newspapers underneath the generator to absorb the mess, and open a window. That will free it up if it's stuck.

Check the condition of the mains AC wiring. If brittle, don't power it on, replace that wiring. I think I already discussed all of that earlier. Most of the wiring is cloth, but the incoming wiring is some kind of rubber insulated material that is most likely crunchy by now.

[KeithB]

Do not use naphtha. If it is full of gunk, use acetone. It will work as well (maybe better) and is no where near as toxic!

I know this is sacrilege here as many have used and continue to recommend naphtha, but I am a chemist and am able to read and understand material safety data sheets (as all should do who use industrial chemicals), and naphtha is not something you want to be breathing. Acetone will work just as well, is far less dangerous, and is easier to get (home centers).

Please, when using any solvents, or other hazardous chemicals, know what you are doing.

[muckelroy]

Acetone will work just as well, is far less dangerous, and is easier to get (home centers).

Please, when using any solvents, or other hazardous chemicals, know what you are doing.

I’m not a chemist. I just have a hard time with acetone when I use it in scanner cleanings. It leaves behind quite a residue on the stators and insulators. It wipes off fine but I have better results with denatured alcohol for direct metal and bearing cleaning like scanner stators.

I also use denatured alcohol when the generator is removed and belly-up on the workbench cleaning bearings and clutches.

People on this forum have recommended naphtha for its ability to flush out the gunk from the oil wick threads.

Maybe acetone does the same thing to oil wick threads as naphtha. If it works for you, more power to you!

[KeithB]

Yes, alcohol would be better also. Naphtha would be one of the last chemicals I would use from a safety standpoint. It may do a great job as a cleaner (it's a good solvent), but it is a mixture of hydrocarbon compounds, some of which are known to cause cancer (benzene, ethylbenzene). It can also be absorbed through the skin, so that is an additional danger (in addition to breathing the fumes).

[PGR]

That's interesting KeithB as a chemist you would be able to rate some of the chemicals we use a lot of here in terms of risk to humans and advantage to function say That type of chart would be helpful to someone like me ... IF you could share that detail some time It would be beneficial to everyone re your choice of chemicals for specific usages based on your background.

[SunwoodRecording]

Ok. So far I've replaced the leg screws with bolts (and soon will add casters on the feet), removed the whole lid (the rear of the lid came detached, so it's leaning to the side with the vibrato still connected), propped the manuals up, and have compressed-aired and shop-vac'd the s*** out of the thing. I removed the preamp for servicing, and hooked up ac power to the tonewheel generator. The starter motor wouldn't initially engage with the tonewheel driveshaft (which I would owe to lack of lubrication), but with a little coaxing (and following proper hammond startup procedure) I got the thing to 'run'! Didn't leave it on for long, as I still need to flush the TG with alcohol (do I spray down the whole TG? or just put denatured alcohol in the oil cups?), and lubricate the thing, but now I know at least it's mechanically functional. (the shaft was spinning smoothly by hand, so I thought, 'why not fire her up?')

I also noticed a little box in the rear of the cabinet that is tied into the preamp, and has lamp cord exiting out under the manuals. I'm guessing this had a switch connected at one point, possibly for leslie control?



Also, there is a hole through the music rack with a label "normal vibrato < *hole* > vibrato chorus", and a switch (lacking an actual 'rocker') floating around in the back connected to the vibrato box under the lid. Could this also mean the organ was converted to a BCV at some point? Or is this standard on a BV (muckelroy mentioned this switch in the initial reply)?



I don't have a visual frame of reference for whether the TG capacitors are in good shape, but none appear to be fried. One also appears to have been replaced (see pic). Should I replace the rest while I have it open, as they're likely 70 years old? Or should I wait and see if it sounds good/quiet/not-buzzy first?



Are there particular capacitors I should seek out for optimal sound quality? I'm sure I'll have more questions, and I have to say I really appreciate all the information this community has provided so far! Thanks again y'all!

[KeithB]

If the TWG and motors are turning, I would just put oil in and let that lubricate everything. No need for an alcohol flush, as the oil will eventually dissolve any residual gunk anyway. All the alcohol is going to do is dissolve the gunk and redistribute it when the alcohol evaporates. That’s ok if things are stuck, but if everything is moving, you don’t have enough gunk in there to cause a problem. The point of using a solvent is to dissolve built up, high viscosity residue left behind from the last time it was oiled. This is useful if the residue is causing the TWG/motor, etc. not to run. If it’s running, just oil it.

[muckelroy]

Ok. So far I've replaced the leg screws with bolts (and soon will add casters on the feet), removed the whole lid (the rear of the lid came detached, so it's leaning to the side with the vibrato still connected),

I'm a little confused by what you mean. "Lid" as in the fallboard, "Lid" as in the back cover, "Lid" as in music rack, or "Lid" as in the top section of the organ's main case? I see you have the music desk (base) but no music rack installed.

with a little coaxing (and following proper hammond startup procedure) I got the thing to 'run'! Didn't leave it on for long, as I still need to flush the TG with alcohol (do I spray down the whole TG? or just put denatured alcohol in the oil cups?), and lubricate the thing, but now I know at least it's mechanically functional. (the shaft was spinning smoothly by hand, so I thought, 'why not fire her up?')

I agree with most of what KeithB said, in that if you're not planning on removing the generator, stick to oil only if the thing is spinning. You may need to let the oil soak in for a couple weeks for best results. Alcohol is best for when the generator is belly-up on the bench, as it can be squirted at a close distance to the bearing itself, and followed quickly with oil.

I also noticed a little box in the rear of the cabinet that is tied into the preamp, and has lamp cord exiting out under the manuals. I'm guessing this had a switch connected at one point, possibly for leslie control?

Yes, that is most likely a Leslie tremolo control. The sticker appears to be missing - is there one on the back? It's probably a typical 428 type meant for Leslie 122 (6H) types. The brown lamp wire is supposed to be attached to a toggle switch, half moon, but these have a tendency to get lost or smashed in transit. Is it hiding or dangling somewhere? You don’t want those wires to be bare if no switch is there. Cap them or tape them together until you can find a suitable tremolo switch.

Also, there is a hole through the music rack with a label "normal vibrato < *hole* > vibrato chorus", and a switch (lacking an actual 'rocker') floating around in the back connected to the vibrato box under the lid. Could this also mean the organ was converted to a BCV at some point? Or is this standard on a BV (muckelroy mentioned this switch in the initial reply)?

That is where the Vibrato / Chorus toggle switch is supposed to be. It is a SPDT switch, but the original is one of the massively long telephone reed switches.
Here's what the schematic shows for that switch, as well as a photo of the back of that switch on my CV. It's very long, and the music desk hole is quite deep. You can only see the back 1/2" poking out.

I don't have a visual frame of reference for whether the TG capacitors are in good shape, but none appear to be fried. One also appears to have been replaced (see pic). Should I replace the rest while I have it open, as they're likely 70 years old? Or should I wait and see if it sounds good/quiet/not-buzzy first? Are there particular capacitors I should seek out for optimal sound quality? I'm sure I'll have more questions, and I have to say I really appreciate all the information this community has provided so far! Thanks again y'all!

I would suggest you do some reading and research on this topic. You'll almost never see "fried" generator capacitors, because they don't ever pass high voltage. They only pass small amounts of AC voltage in the form of sine waves. You have original paper and wax caps. Someone, at some point replaced one. I would not be surprised if the black "replacement" one is still close to value. The other ones are probably the original paper and wax caps, which have a tendency to absorb moisture over time and increase in capacitance. This in turn increases the "Q" resonant frequency of the LC filter, which causes that tone to go down in volume. You end up with inconsistent gain as you ascent the scale. Tones 49-91 have these capacitors, and they will benefit from being replaced. Some would tell you to leave them be and listen to the organ first. If you seriously like the way it sounds, leave it. If it sounds too dark, then re-cap it. If you want to take it to the max, peak it out with trim capacitors and the help of an oscilloscope, then calibrate it via the pickup pole adjustors.

[Tim_at_Jonas]

I would make the top removable. (With great care not to damage any wires) This allows the manuals to be set straight up, allowing easy access to the top of the generator. It's also a lot easier to work on drawbar wires and misc.