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Thread: A100 rehab

  1. #1

    A100 rehab

    Hey all! I finally mustered up the bucks to buy an A100.. I've paid for it but I don't have it yet, gotta go pick it up next week across town. I'm pretty sure its a 59, its very dirty, but it did start up and all the tones work. I'm starting this thread now, but I know I'll have plenty of Q's later on to add. What I know right off the bat: Reverb not working, though I can hear when I bang the springs together, so its something in the send, not the return. Percussion is very quiet and not working right. Organ is fairly loud, and a bit muffley sounding through the internal speakers. I have a 147 that might brighten it up.. Its got a cracked key and a missing veneer strip, kinda looks like me. I'd like to know a few things: I plan on recapping all the amps, the old wax/papers look pretty bad. I know most people like to recap the TG too. Would that require a TG calibration? Why? Is it because the 'old' values aren't available anymore? What caps do you guys use, and why are they so expensive? A quick search for a .1 uf 100v cap, about 35 cents each. I saw someone on ebay selling a set of old stock Mallory 'red caps' for a complete TG job. They've been snipped short, and have lead extensions soldered on. Are these caps worth buying, like will they sound noticeably better and would I still have to recalibrate the TG? They went for about 50-60 bucks IIRC. I don't remember the stock cap values in an A100 but the ones sold in this kit are mostly .1 uf and a few .25 uf, which seems like the harder value to find. Which tones take the .25?

    Everything in this organ will probably need to be rebuilt, but it was played gently in a church most of its life so at least the keycombs are tight!

    A bunch of Q's for yall to start of this dirty magical oily fingerburnin journey into the depths of this beast.. Thanks in advance!

  2. #2
    Senior Member indianajo's Avatar
    Join Date
    Dec 2009
    Jeffersonville, Indiana

    Before working on any tube amp, read tech button, technician safety button, about not killing yourself electrically. Simple rules but you have to follow them. First off your paper caps may be 30% off in value, but your electrolytic caps that look good may be 100% off. They are aluminum cans filled with water sealed with rubber, and nobody drives 1959 tires anymore. The ones above the deck have circles, triangles and squares for the plus parts. The ones under the deck have cardboard wrappers and a plus on one end.See my posts in this article about how to cheaply buy new electrolytic caps and install them under the chassis. You can also buy electrolytic caps kits from KC or in Ontario, using undefined life new cans. These two are also known reliable sources of oil for Hammonds, which you should install soon and yearly thereafter. Two funnels on the TG and dampen the pad in the scanner tray. Don't fill the scanner drum with oil if you don't have a an oil tray and a thread, just a few drops.
    The Vishay Sprague orange drop caps are recommended to replace the paper ones because they have long leads and install easily. They also have a defined sound that people are used to. They are expensive because they are made in USA where Vishay actually pays the workers a living wage unlike the *****s that make caps in c****. Hammond originally selected the coil size to match the cap variations, but you are stuck with the coils you have got already. See for an instruction on how to tune your pickups to the cap. I view paper cap replacement on the TG as an artistic decision, as many LP's were made with paper caps on Hammonds mellowed by the lack of highs. The Mallory film caps on e-bay are used and might be okay, or some might not be. The paper caps connected to the tube plates in the amps have had more stress from high voltage, and actually do fail occasionally. Guitar people invariable replace caps in this position in their amps, but goodall is a better cap than many guitar amps used and I have had only 1 failure in a plate cap, and that one had the wax case burned through by the kit builder back in 1961.
    If your percussion and reverb don't come back to life after re-e-cap, then check your light bulbs on the reverb. If your reverb has 3 tubes instead of 5, another common failure point is the germanium transistor. If anybody ever pulled a tube out with the power on, the lack of a silicon voltage regulator runs the collector voltage on the Ge transistor sky high and blows it up.
    A100's in perfect shape are less strident than leslies, because they only have 12" speakers. Not liking the constant woo-woo-woo-woo of leslies, I'm thinking of putting a 3" car speaker in place of or in series with one speaker in mine to pep up the key-click.
    As far a complete rebuild, hammonds have precious metal contacts and probably only need playing to knock the dust off and bring them back to life. More common is refelting to improve the key movement consistancy. See bobmann47's u-tube videos. Occasionally a rectifier tube needs replaced, and long hour units might need the power output tubes. These are available from the organ supplies above or or, that also sell the cinch terminal strips for installing the radial lead electrolytic caps under the deck. Minimizing freight costs by consolidating purchases is part of my economy plan. I bought a replacement key from and his website has such clear instructions I didn't need to call him. (I don't have long distance phone service). The key mount screws are 6-32 x 5/16" if you drop and lose one. If you are in Canada, use Royal Mail for shipments from the USA or buy from Ontario, UPS and FedEX charge horrible paperwork charges for crossing the border. If you receive at a house, USPS priority mail is cheaper than UPS or FedEx because of the residence surcharges.
    Last edited by indianajo; 04-24-2012 at 09:33 AM.
    city Hammond H-182 organ (2 ea),A100,10-82 TC,Steinway 40" console piano, Sohmer 39" piano, Ensoniq EPS, Wurlitzer 4500, Dynakit ST120, ST70 amps, Herald Ra88 Mixer, Peavey SP2XT speakers,BIC turntable; country Hammond H112.

  3. #3
    Senior Member TheAdmiral's Avatar
    Join Date
    Dec 2008
    Gulf Coast of Alabama

    A very common problem with the reverb are the RCA connectors that have corroded. Clean them with Deoxit first before troubleshooting further. You may save yourself some time.
    Hammonds: A; AB; B3; D; E; 6-M3's; 2-A100; T582C.
    Leslies: 3-31H; 21H, 22H, 4-44W; 46W; 25; 47; 45; 125; 50C; 51; 55C; 2-120; 122; 122A; 145; 147; 245; 770; 825; 2-102; 2-103; 300.
    Wicks 2/5 pipe organ; Yamaha upright; Kurzweil Micro Piano & Micro B with M-Audio Oxygen 61; Yamaha DGX520; Wurlitzer 4100 (it came with a Leslie!). Peavey KB100 keyboard amp. Peavey Bass Guitar. Yes, I have A. D. (acquisition disorder) and don't want it cured.

  4. #4

    Congrats on your find! The early ones like your '59 are really nice ones. Yours should have the necklace style reverb, which will need to be locked down like the tonewheel generator, before you move it.

    Quote Originally Posted by goldnmold View Post
    I know most people like to recap the TG too. Would that require a TG calibration? Why?
    I think this is one of those things that gets thrown around a lot out here on the web... but don't believe everything you read. I've owned a dozen tonewheel Hammonds now, going back to a '59 C3, and not one of them has needed a full TG recap job. (Though I did have one CV that had one bad TG cap.) Here's what I'd recommend: definitely rebuild the amps as needed first. Then, play it and listen to it! You may well find it sounds great at that point. If not, then's the time to start thinking about further steps like recapping the TG.

    Anyway good luck with it -

    Nobody loves me but my mother,
    And she could be jivin' too...

    --BB King

  5. #5
    Senior Member sfp1954's Avatar
    Join Date
    Oct 2011
    Rumford, RI USA

    The reverb pot is a 100 ohm wirewound pot in series with the reverb speaker. They can get quite scratchy and develop bad spots.

    Rebuilding the premp/amp/reverb amp is obviously the first priority.

    If you're going to recap the TWG don't forget to also do the Vibrato/Chorus Line Box.
    I have a set of .255s Orange drops you can have. They are the 6 long ones on the back of the TWG but the replacements can go directly on the filters.
    I probably also have enough .1s left around as well, but any .1 poly or mylar type is fine.
    Most people who have hand calibrated TWGs (by adding/subtracting capacitance) actually find the peak value to be about 0.098 for the 0.1 caps.
    But is that a humanly audible change? I don't think so.
    Remember that in the day caps were only rated at 20% tolerance.

    As far as calibration my advice would be to recap the TWG and then use your ear.
    If any individual frequencies are too loud or too soft then the magnets can be adjusted.
    Attached Images Attached Images
    1969 Hammond A-105, Leslie 22H, 1961 M3
    XK3-C, VK8-M, Boss RT-20, Neo Ventilator
    Roland XP-30 (3), XV-5080 (2), Various Fatar/Studiologic Weighted Contollers (SL-1100, 1176, 880)

  6. #6

    Yes, I know all the electrolytics will be pretty far gone, and I'm lucky they even powered up. Who knows how long that organ has been in that guys garage. I also know plenty about rebuilding and recapping amps, I've done my fair share of guitar amps, as well as my M3, so at least this ain't my first rodeo! I guess I'll leave the TG alone for now, there's plenty more to do. The scanner will also need a good rebuild, but I've done that before, so no biggie. Thanks for the advice so far, I know I haven't even scratched the surface yet...

  7. #7
    Junior Member Jazzman1's Avatar
    Join Date
    May 2010
    Burton, Ohio

    I recently replaced all the electrolytics in my A-100, and after re-assembly had no reverb either. The problem turned out to be the two No.2 lamps inside the reverb amp. Ordered replacements from the local electric supply house, put them in, and voila! It works, and sound great! New caps made a world of difference in volume, and clarity of both highs and lows. Be careful around the necklace reverb as they can be delicate and a bit tricky to re-assemble if they come apart. I also had to replace the sheilded wire with the RCA jack that runs from the tank to the reverb amp. The exterior sheilding was good, but the insulation on the inside conductor was failing. Now I just need to figure out why the reverb speaker farts-out on C# on the lower manual. Good luck.
    A-100, M3's (3), 21H, 31H, PR-40, and way to many guitars.

  8. #8

    Well I bought a set of vintage red mallorys on ebay because they were half the price of a new cap kit! We'll see how it goes. All caps are tested within 10% of spec according to the seller. I have an H111 too that now needs to go to make space! Its funny, for such a ridiculously appointed organ, nobody really wants them. I bought mine for 100 bucks 5 years ago, that guy must have been psyched! I'd be thrilled if I could get any money for this thing. Even working, its hard to give away. So I was thinking, what about doing some part swaps? What if the extra big TG of the H100, along with its extra drawbars, was implanted into the A100? I haven't measured anything, but assuming it would fit, how tough would it be? Seems like I have the ingredients to construct an A100 the likes of which THE WORLD HAS NEVER SEEN!!!! I remember thinking about trying to outfit the H100 with an AO28 to get 'that' sound with the extra tones. Seemed like a lot of work and I still hate the H100's keys. Thoughts?

  9. #9
    Senior Member indianajo's Avatar
    Join Date
    Dec 2009
    Jeffersonville, Indiana

    I can't do anything about the H100 keys, but they have "that" sound within, it is just buried in the theater stuff. The A100 has undertones instead of overtones on the top octave and a fifth. The H100 has actual overtones up there. Just a matter of rewiring. The A100 has lower resistance wires on the top octave and a fifth, the H100 has the same resistance all the way up since it has actual highs. Another bit of rewiring. Actually has some capacitor changes drawn up to take the highs out of the H100. That is a little permanent for me, I might actually pull the sound out of the reverb outlet and run it through a graphic equalizer to kill the highs. I can also run it into a digital effects box I have for the reverb of 50 kinds, or flange, or rotary speaker or whatever, programs 1 -400.
    The A100 has "twos" and "threes" percussion, the H100 has banjo and xylophone. A matter of rewiring to get the sixth around the xylophone to make twos and rewiring twos, fourths, fifths and sixths overtones around the banjo switch to make threes. Then you can fool with a capacitor in the percussion amp to get whatever timing decay you want on the percussion. You could control the fast/slow with the harp vibrato switch or something else useless.
    The H100 has tabs where you can flip the switches with your third finger while you hold a note with your other fingers. The A100 has switches on a panel where to change them you have to dedicate an entire hand to doing it. This is superior?
    Frankly, nobody knows what an H100 sounds like but me, Bobmann, and some guy in Hamburg, Germany. Nobody else has changed the 71dried up electrolytic capacitors. With new caps the H100 has thunderous bass and sparkling high tones. Without them the H100 sounds like a tired kazoo reproduced on a Bozo the Clown record player with a paper cone amplifier. I like A100's okay but I like a restored H100 a lot better. But then I don't do glissandos with my elbows the way B3 players do. I use a fingernail.
    I've bought a Shure KSM27 mike to make a recording of H100 before and after recap, but I'm having computer problems with the PC that might be capable of making recordings. Maybe next electronics season, it is car mower and roof season now. I won't be making any recordings with a cell phone, that makes anything sound like ****.
    The big advantage of the A100 is that even though the e-caps are ****, there are so few of them that a decently repaired Leslie can put them back to close to what people are used to them sounding like.
    It is true there are More H100's than there are people with room to work on them, the skills, and the truck to move it. Thus the price. What I really like is I can play serious classical music without it being embarrassing (as a C3), at the same bench I can play Kingsmen and Mancini, and I can go right on to play Lynard Skynard or Joan Jett the same night. If I do the percussion mod I could play Groove Holmes "B3in" album at the flip of a switch. Try that with your Allen organ or B3. Yeah, I know, I'm some kind of prevert for liking JS Bach, Buxtehude, Tschaikovski, Alman Bros, Lynard Skynard, Henry Mancini, Chapman-York and Billie Strayhorn. You are supposed to like only one kind of music and listen to one radio station all the time. Plplplplplpl!!!
    Actually there is an injection molding company 500 yards from here that could make waterfall H100 keys. All it takes is a $10000 molding die and some serious interest by people in converting them.
    Last edited by indianajo; 04-29-2012 at 04:21 AM.
    city Hammond H-182 organ (2 ea),A100,10-82 TC,Steinway 40" console piano, Sohmer 39" piano, Ensoniq EPS, Wurlitzer 4500, Dynakit ST120, ST70 amps, Herald Ra88 Mixer, Peavey SP2XT speakers,BIC turntable; country Hammond H112.

  10. #10

    I'd really rather sell the H, is anyone interested? I'm in NH. I see one that recently sold on ebay for $550 in VA. Wowee. I'd deliver it free to VA for that kinda money! If I try do some transplant I'd end up making a huge mess and having two half working organs for the next 5 years. Sigh.
    If I had the room and the stamina, I'd fix up that H100, I've heard you talk about your recapped H like its the voice of God! 70 something caps ain't actually that bad. But my basement just ain't big enough. I also have an M3 that's gotta go. I have to keep a 2 organ limit, and my lowrey brentwood is just too special to give up.

    But has anyone transplanted one of these mega TG's with the extra drawbars to a B or C style organ?

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