Except where noted below, maintenance questions regarding the manual itself are mostly addressed in the fretted clavichord maintenance manual online at GaryBlaise.com. While that manual was written for a different fretted model, most of the information is relevant but follow, for example, the temperament for Van Bizen and the string schedule written directly on the soundboard when changing strings. Issues regarding peculiarities of the pedal are addressed below. It is probably best to read this and the clavichord manual before performing tuning or maintenance upon the instrument. For further questions or information, please call Gary Blaise 415-552-1934 or e-mail me at through the website or gablaise@hotmail.com.
The ASU Pedal Clavichord is of the pedal pull-down type (as opposed to the independent pedal instmt type as Gerstenberg) but with an intermediate lever system which more precisely reconciles the large spacing of the pedal levers with the smaller spacing of the key levers. The pedalboard sounds the lowest 27 notes of the single manual fretted clavichord built in the style of C.G.Hubert.. Every possible dimension of the instrument has been built to mimic ASU’s organ by Paul Frits, opus 12, in order to optimize the practice experience. In this way, the intermediate levers also allow the pedalboard to be positioned farther back than the standard pull-down would otherwise allow.
The pedal system is a simple one works as simply as it will appear to any early keyboard maintenance person. It consists of familiar components and is easily accessible. Basically, the pedal levers pull trackers which pull levers which push stickers which push up under the ends of the bass keys below the tangents.
The Pedalboard Frame:
The pedalboard frame, and the levers, are more lightly constructed than the usual organ pedalboard. The frame is mostly pegged together and held in place by by tension provided by means of a turnbuckle. The guide rail and the spring rail are screwed and pined in place together. These screws, and others around the instrument, are typically covered by maple buttons which are easily popped out for screw access. Be sure never to over-tighten any screw upon replacement. The spacing of the pedal levers is established by means of 1/4” wooden dowels which have been press-fitted into the guide rail. Felt pads on the pedals fine-tune this spacing and prevent noise. They can be adjusted with paper shims if necessary. It is important for the frame to sit properly on the floor and the wooden shingles, provided, may be necessary to reconcile an uneven floor under the frame.
The felted guard rail is designed to help prevent catastrophic damage to the components of the instrument in the case of vandalism or the gross overplaying of the pedal levers. To a large extent, this rail also prevents bebung, that is, it evens out the volume of the pedal. The rail can be removed for adjustment should rattling occur as a result of an uneven floor or looseness between the rail and frame. Pedal depth can also be adjusted by shimming or trimming the little foot pads underneath the rail. The rail can be removed for adjustment by loosening the turnbuckle, lifting the instmt at the rear hinge rail, and sliding the guard rail out of the instmt.
The rear rail, to which the pedals are hinged, is covered by an over rail which screws in place, the screws covered by maple buttons in the manner described above.
The Pedalboard Levers
The pedals are connected in three places. Flexible wooden projections act like hinges and attach the rear of the pedals to the frame by means of a screw (the assembly is covered by the over rail, above). The wooden hinges are also springs and their tension can be adjusted by those same screws. The pedals are also attached to the spring rail behind the guide rail by a wire spring which hooks into an iron eye, padded with cotton for noise. The 14-guage brass spring is adjustable by simple bending and should only catch excess weight which can not be caught by the intermediate lever spring alone and little more. If the pedal lever is hanging loosely by the spring, not solidly returned against the guide rail, the spring is not catching enough weight and should be tightened only after firstly adjusting the wooden spring, above. You would also know if the spring is not catching enough weight if the intermediate lever is at all rising at the front end under the tangents. Lastly, the pedal ends are attached to the trackers by means of 50 pound test non-stretch braided fishing line.
Although the pedals are stopped by the guard rail, an unintentional and very quick impulse to the pedals could cause the intermediate levers to continue moving, pushing the sticker buttons up over the backrail where they can become stuck. This is because the pedal and intermediate levers are each accelerated and free of the pedal levers much in the way a piano hammer accelerated and free of a piano key. This should be an unusual occurance since such an event would also push the tangent up through the strings.
The Trackers
The Trackers
The trackers are softwood with a metal hook at the pedal end and 50 pound test non-stretch braided fishing line at the adjustment end. The hook’s diameter has been increase to 5/64” at the attachment point for longer string wear. At the other end, a tapered maple adjustment peg fits into a tapered hole in the intermediate lever. For the instrument to work properly, the tracker must be not be slack yet it must not be so tight that it is at all lifting the intermediate lever at the front (opposite) end under the keylevers. The string must wrap in an even spiral around the peg to remove all slackness from the system during use. Also, the string is guided through a slot along the back of the lever and must go through a small .024 brass wire loop underneath the lever to insure the proper leverage point and eliminate mechanical inefficiency as much as possible. It is not essential that the string be in the slot but it must be through the loop and not slack anywhere. Like a new string, the tracker may need some occasional tightening if it has been removed and re-installed.
The Intermediate Levers
These levers are cut from a single block of wood made up of wedge-shaped pieces which were carefully glued together such that grain direction is sufficiently maintained along the length of the levers for strength. The levers attach to a balance rail which is hung from the underside of the manual instrument. The lever system as a component should not require removal from the clavichord yet individual levers can be removed if necessary. Should removal be necessary, the three hanger bolts and diagonal braces are disassembled in the obvious manner only after the entire instrument is disassembled as per the other sections of this manual. Marks around the edge of the balance rail indicate their proper distance in millimeters from the underside of the case, 140mm. The bolts are adjustable to maintain this distance.
The levers are guided by their balance pins and by felt pieces glued towards their front ends. They rest upon a layer of wool cloth at the balance pin and upon 2 layers of woven wool cloth under the front at the sticker end. The front rail cloth can be increased to control noise or adjust the action height if needed by the addition of more cloth or paper shim. The levers are attached to the instrument in three places; the tracker adjustment peg (and brass loop), the balance pin which is actually a return spring, and at the sticker end. Spring tension is not easily adjustable. It is designed to just return the entire action and no more. Where it can not, the pedal springs make up the difference by just supporting the excess weight of pedal and tracker. If a lever is not returning to resting position, the spring wire can be bent as a last resort after all other more likely causes have been investigated. The sticker wire terminates in a prong which is wedged into a slot at the front of the lever, easily accessible from under the manual. Remove it very carefully with a fingernail or soft pry-tool without distorting the soft wood of the lever. Should the wooden clamp slot become damaged or enlarged, the prong may be moved to another point along the slot or a shim could be used to restore tension. The head of a tiny pan-head screw could also be used to secure the prong against the face of the lever and holes have been pre-drilled there for that purpose.
For lever removal, the lever is carefully pried up over the balance pin after detachment of the tracker and sticker. Upon replacement, it is very important not to distort the opening of the balance hole in the soft lever.
The Stickers
The stickers are .047” steel music wire. Each L-shaped wire sticker has a prong at the lower end and a maple button at the upper end. The prong is wedged into the front of the intermediate lever as described above. From there, the tracker rises up through a tiny hole in the bottom of the case which has been bushed with a paper. The top of the button is padded and the keytail rests directly upon the button pad. A black dot under the keytail marks the contact point. A tiny spring of .024” brass wire has been let into the pad to help return the sticker to rest. The underside of the buttons are also padded with a thin felt to control noise. The buttons rest in rather crudely made cups cut into the back rail. Should a sizeable piece of dirt drop into this cup, it could prevent the full return of the sticker and, hence, the action. For this reason and in any case, it is essential to always close the lid when the instrument is not being used and not let dust, eraser bits, and other contaminates get into the case of any string keyboard instrument. Should it be necessary to clear suspected dirt from under a sticker button, the key must first be carefully removed from the instrument. The spring wire must next be pried up through the slit in the felt button pad and placed alongside the button. Lastly, the prong must be very carefully removed as described above. With the sticker free, it can be manually raised up, through the stringband if necessary, thereby revealing the cup and any dirt which can be sucked, blown, but preferably, picked out with tweezers. Generally, it is not a good idea to completely remove a sticker from the instrument which requires removal of the press-fitted button and felt pad as the press fitting can become loose.
Occasionally, a sticker button may become hung up on the back rail, preventing the return of the keylever and intermediate lever. Remove the key and free the button. Replace the spring in its slit if it has become dislodged.
The Stand
The stand consists of four legs rising up from the pedal frame, the front two which are screwed in place from the inside of the frame, the rear two which are connected as a unit and lift up off pins in the frame. The wide cross member of the rear leg unit is there to help prevent catastrophic damage to the trackers which might be caused by a player’s foot. Should a front leg require removal, three pedals must first be removed which will permit enough space for a stubby screwdriver to remove the leg screw. Let into the top of the two left legs are steel arms, screwed in place and bolted to the underside of the manual. These arms are covered by blocks which screw to the steel arms from the underside. The front right leg has a positioning pin which fits into a protected steel bezel (hole) on the underside of the instrument. This pin also holds a diagonal brace in place. There is also an adjustment screw in the top of this leg which must be adjusted to keep the manual from rocking as the clavichord picks up a slight warp over time. The rear right leg is held in position by the diagonal brace between it and the front leg. With the diagonal brace unscrewed, it is possible to lift the manual just enough without disconnecting anything in order for the front right leg pin to clear the bezel and be rotated forward to access the adjustment screw.
5/16” threaded T-nuts have been installed into the bottom of the instrument at the corners for use with screw-on legs as a future option for use of the manual alone.
Tangentboard
The tangentboard is a rifle-shaped thing and fits in place over the listing cloth. It is designed to help prevent bebung in the pedal as well as prevent the sticker buttons from becoming stuck in the case of accidental overplaying of the pedal. The sticker button can otherwise pop up over the back rail and become hung up on the back rail. To install, the rail is first pinned on the left and then nudged into position where it is screwed securely from the back of the instrument. It must be removed for string replacement and for guide pin adjustment. It can also be removed for playing the manual alone if desired.
Troubleshooting the pedal
action noise
- check for loose tracker strings and tighten peg
- check pedal return springs. unhook spring and add more cotton as needed
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- check intermediate lever guide felts and add paper shim as needed
- check sticker button (release as above and add a little cotton underneath
- check pedal guide felts
deep pedal action
- check if pedal not fully returning. tracker string needs to be wound up more at peg
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shallow pedal action
- check if intermediate lever not fully returning to rest. tracker string needs to be loosened at peg
- check pedal spring tension. adjust wooden hinge/spring first; then metal wire spring
stuck sticker
- check for dirt in button cup as above
- check paper shim and remove if crumpled (pulls out). Do not replace.
- remove key to see if button is hung up on back rail. Free button. Reposition little button spring. Replace key.
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stuck pedal
- check for foreign object under return rail
- check guide post damage or remove a felt if for seasonal wetness
stuck intermediate lever
- check for foreign object or crumpled felt under lever
- check for stuck pedal not returning (above)
- check sticker button and free if needed
excessive instmt or bench wiggling
- check if instmt has to use the bathroom
- check for loose stand screws, especially diagonals
- check for bench looseness and tighten or repair right away!!
- check and adjust warp adj. screw at front right leg-top of manual
catastrophic pedal regulation problems
- check if pedal frame was moved and is properly seated on floor
- check stand for wigglyness and that horizontal steel stand arms have not come loose at the manual.
- check intermediate lever hanger bolts for tightness and re-tighten at correct distance as above
- check intermediate lever balance rail clearance to case bottom as marked, 140mm
- check for objects blocking return of pedals (crumpled felt, dead mouse?) or the intermediate levers (eraser bits or dried café latte in button cups? Mangled or rusted sticker wire? crumpled button return spring under key?)
- check for completely loose tracker adjustment peg and reset
- check for broken tracker string or broken pedal hinge springs
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