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Messages - sean

Pages: 1 [2] 3 4 ... 31
31

SteveO - hah!  I beat you by 77 seconds.

Wanna race on the next one?

 ;)

32

JB,

RTFM  http://www.fenderrhodes.com/org/manual/toc.html
Bookmark this site:  http://www.fenderrhodes.com/

Especially see:  http://www.fenderrhodes.com/org/manual/ch4.html#4-7
See also http://www.fenderrhodes.com/service/tine-settings.html

Play around with the pickup position and the timbre adjustment screw.  You will find your sound.

The timbre adjustment screw is the leftmost screw/spring in this diagram:
http://www.fenderrhodes.com/org/manual/ch4.html#fig4-3
(That is the tonebar adjustment screw that is closest to the rear of the piano, closest to the pickups.)

To make the notes louder, you can slide the pickup closer to the tine tip - loosten the pickup mounting screw, gently nudge the pickup to get it unstuck from 47 years of living in one place, then slide the pickup forward so that it is closer to the tine, gently re-tighten the pickup mounting screw.

Have you confirmed that the hammers are indeed contacting the tines?  If the escapement is abnormally high, sometimes the hammer will hit the end of the damper arm before it gets to the tine.



Sean

33

... only about 460 miles away.  Nine or ten hours of driving each way, plus $70 of gas each way.  Hmmm....  Ouch.

34


TC,

I have exactly what you need. 

I have the remains of a c.1973 Rhodes action:  73 Pratt-Read full-skirt keys on a keybed, wooden action rail with half-wood hammers, bridle straps, individual damper arms, and tooth-root damper felts. 

It is missing the harp, missing case, missing balance rail felts and front rail felts, missing the name rail, and strangely missing the wooden support for the action rail (the strip of wood that goes between the keybed and the action rail).  I think I have the cheek blocks too. 

The action is now clean, but still needs some work.  The balance and front rail pins were rusted, and have been sanded down.  They are not as smooth as ideal.  About 22 of the keys stick (they don't return on their own volition), and need to have their sides sanded down until they no longer touch their neighbors.  (Two keys at the bottom, two keys in the middle, and then nearly every single key in the top two octaves.)  This means that the action was exposed to water, and the keys are warped (or maybe just swollen?).  However, every single key looks perfectly straight when removed from the action.  I think they all work when I remove the neighboring keys, but I should test that to verify.   Every key pedestal seems to mate with the key above just perfectly, so I don't think this action is too far gone.


Where on planet earth are you?  Toronto?  I am in USA, near Washington DC.  Send me a PM with your email and phone number.

Sean

35

JB,

You can tap the tip of the pickup with a screwdriver, and it will make a LOUD pop and clank as the magnet makes the screwdriver slam against the pickup tip - so turn the amp gain way down.  I have done this, but it is never an enjoyable method, and you don't really need to put your speakers through this torture.

However, it does help in the situation where you have one very quiet note, but you refuse to believe that the pickup is dead.  If one pickup is dead in a group-of-three, the neighboring pickups will still create some current in reaction to the moving tine.  The note with the dead pickup will sound quiet and ghostly, but audible.  If you tap the pickup on the quiet note, you will get no loud pop when the magnet grabs the screwdriver.  Then you can confidently declare the pickup dead.

Sean

36

JB,

My Ouija board says that the loops of wire between pickups running along the back solder terminals is touching a little loop of wire that connects the front solder terminals.  This could be anywhere in that group of three, so at pickup 61F, 62F#, or 63G.  But that would only short out three notes.   Hmmm... could this be the problem in each of the groups above that?  I doubt it.

It could be that the pickups are all pulled back away from the tips of the tines, or that the pickups are not well-aimed at the tines, of that the treble on the Crate was turned all the way down, or that the strike line is way off so that the hammers are not hitting the tines, or that all the tuning springs on those notes have evaporated, or that your ears are broken and can't hear above 1390Hz (run to the doctor!  You are the patient zero!).  Check some of these ideas, ignore others.

I really enjoy guessing out of the blue, but photos always help.

Sean

37

JB,

Your Rhodes almost certainly has a few dead pickups.  (I love the 1973 year for Rhodes Pianos - half-wood hammers, square hammer tips, tooth-root-like damper felts, full-skirt keys, very sharp edges and nose on the black keys, etc.)

The pickup rail is wired with pickups in groups of threes.  This is a series of 24 groups of [three pickups in parallel]  (one group of four at the low end).  Each group of three pickups in parallel looks like this:


If all three pickups in any [group of three] are dead, then the whole piano makes no sound.  The pickups die for one an only one reason:  the thin winding wire has broken (usually from corrosion at the spot where the wire leaves the winding and bends around the end of the bobbin before it reaches the solder terminal).

Here is some advice plagiarized from the links below:

Dead pickups are the most likely problem, but a super-dirty RCA jack is a possibility.  Obvious missing wires or broken solder joints should be found with a careful eye and a flashlight.  You need some simple tools:  a cheap volt-ohm meter, a bunch of alligator clips, a bright flashlight, an RCA-to-quarter-inch adapter, and your guitar amp.

I would start with the volt-ohm meter, and set it to read in the range up to 20K-Ohm.  Unplug the RCA cable from the back left corner of the harp, and touch your ohm-meter probes to the center terminal of the RCA jack, and the solder lug that is connected to the long black squiggly wire that runs behind the row of pickups.  If you get a reading of something between 1000Ω and 2000Ω, you would jump for joy!  (A perfect harp would read ~1425Ω.)  If you get a reading that indicates an open circuit (infinite ohms), then you have a few dead pickups.   In the rare case that you get a dead-short (zero ohms); then you have to find the mis-wired connection, or the debris or solder blob stuck in the RCA jack that is causing the short.

Buy a bag of six jumper wires with alligator clips on both ends.  (Search online for "clip leads" and spend five or ten bucks for a bunch.)

Use the alligator clips to short out large sections of the pickup rail, and you will quickly be able to narrow it down to which section has the dead pickups.  If you are really unlucky, you may have to short out nearly all of the piano, but probably not. 

If you try to short out an octave at a time, and play the other notes, you will probably get lucky and find the dead section pretty quick.  If not, then use your best and favorite curse words while you short out the bottom octave, and then also short out another octave while playing around hoping for sound.  If that doesn't work, short out the bottom TWO octaves, and then again the other spans here and there while you plink away. 

When you finally get sound, you know that the group of dead pickups is in the regions that you have shorted out. 

Then you can move the alligator clips closer together to short out fewer and fewer pickups until you identify the dead individuals.  Mark the dead pickups with a magic marker.  Then those are the only ones you have to keep shorted, and replace or repair.

Another way to search for suspected dead pickups is to get your brightest flashlight and a good magnifying lens, and look closely at the tiny wires on each pickup as they leave the soldered connection on either end of the winding.  Usually, you will see a tiny green speck of oxidation at the end of the broken wire, or sometimes you might even see that the wire is indeed broken.

Read some of these posts that discuss finding the dead pickups:
https://ep-forum.com/smf/index.php?topic=9989.msg55589#msg55589
https://ep-forum.com/smf/index.php?topic=10079.msg56090#msg56090
https://ep-forum.com/smf/index.php?topic=7116.msg36655#msg36655
https://ep-forum.com/smf/index.php?topic=5620.msg27734#msg27734
(Some circular references.)

Basic method of replacing pickups:
http://www.fenderrhodes.com/service/pickups.php

Sean

38
The Wurlitzer Electric Piano / Re: Wurlitzer 200 Audio Input
« on: July 14, 2020, 05:04:29 PM »

Eau Claire,

Vintage Vibe has a reasonably readable copy of the wurly schematics online:
https://cdn.shopify.com/s/files/1/0666/2821/files/Wurlitzer_200_and_200A_Service_Manual.pdf?8872610067384662061

Go down to page 43 and 45 and right click and select "rotate clockwise."

The schematic on page 43 shows you the resistor values that Wurlitzer used for a voltage divider to provide "tape in" aux; and with no resistors, it would be "microphone in" or "phono in" (without RIAA EQ).  Note that this section of the circuit is isolated from the high-voltage (low current <0.3mA) on the harp by capacitors 55 and 58.

The diagram on page 45 shows you where the connection terminals (3) and (1) are on the left side of the board next to the RCA jack.  (Note that the diagrams for the 200, on page 40 and 42 show the board upside down, so the "mic in" terminals are on the right side, next to the RCA jack.)

If you really are going to carve up your wurly to add an effects loop, you could lift one end of R45 out of the pc board, take the "send" signal from the end of the trimmer pot, build a buffer amp to bring it up to the level that works with your effects, and then just return the signal to terminal (3) through the "tape in."  You could use a switched TRS 1/4" jack (Switchcraft 13b or 14b) to take the effects loop in and out of the audio path, and use an effects loop Y cable.  That doesn't sound super-convenient, just to add phaser, flanger, or delay through the on-board speakers.  I would leave it as-is and use the AUX out and an external amp.


Sean


39

Hey Javartin,

Is your complaint about the bonk or click sound that the hammer makes when it contacts the tine?  (The top ten hammer tips are made of maple wood wrapped with shrinkwrap.  It takes those hard hammer tips to make those super-short tines ring.)

or

Is your complaint about the noise of the key-return - where the back of the key falls and bounces, and the hammer falls and bounces against the pedestal?

Sean

41


Will,

With the preamp disconnected, what do the power feeds coming from the amp cab measure?  (Be careful not to short the pins with your meter leads, it makes an impressive spark.)  The voltage should be very stable, and unwavering, and less than half a volt off the perfect + and - 15 volts.  If they are not close to 15V, then you should replace the 7815 and 7915 regulators (and probably the nearby electrolytic capacitors).   See http://www.fenderrhodes.com/org/ch11/fig11-3.jpg  These regulators create a lot of waste heat, so make sure you get them tight to the heat sink.

[Start making a shopping list of components.  If you are going to pay for shipping or a minimum order, you might as well get extra toys.  Buy yourself a few cheap/disposable solder suckers and some solder braid - oh, I mean solder wick, um solder-removal braid.]

But even if those regulators are bad, that doesn't explain the bad behavior on the preamp board.  Don't give up on your search for a short between traces, and take a good look at the PC board where the switch mounts, and make sure the solder blobs are not making a bridge between traces.

If you suspect that your preamp board is not grounded correctly, check the thin wimpy wires that come from the XLR to the board.  Make sure the connections are clean and tight.  (Also check your 5-pin cable for continuity of the ground terminals from end to end of the cable, and from the board to the far side of the cable.)  Make certain that XLR connector pins are clean and making good contact.

The 2N3392 is a cheap component, and easy to swap out, as are the op amps.  And as long as you are heating up your soldering iron, you should replace the electrolytic capacitors on the preamp board.  If replacing an IC, order a few of the correct size IC sockets, so that future op amp swaps are simple.

When you buy new opamps, get a handful of NE5532 or SE5532 opamps to replace the 1458 opamps that are in the audio path.  You will be able to hear the difference.  When you shop for chips make sure you get the PDIP package, not one of the surface-mount flavors.  PDIP is becoming obsolete on some opamps.  (Leave the oscillator opamp as a slow-slew-rate 1458 chip, unless you are willing to be the guinea pig.)

Even if the oscillator op amp is fried, it shouldn't take down the supply rails.  You should be able to dead-short across pin 8 to pin 4 without making the voltage regulators break a sweat.  Check that the 100Ω current-limiting resistors are still in good shape (see R19, R20, R21, and R22) and close to 100Ω.

Sean

42


Will,

Yep, Fig 11-1 goes with your 013488 preamp.  I don't have that version preamp, but.... 

I guess the first thing I would do is make sure that the preamp has no possible way to come in contact with the aluminum enclosure.  (My Janus preamp got fried when the back left corner touched the metal chassis, and that burned off some traces.  Previous owner had to do some major repair.)   You should put a thick piece of plastic, formica, kapton, or cardboard underheath the preamp PC board.  If and circuit board is simply mounted by the front panel controls with no standoffs under the board, it should have an insulator underneath.

Also, take a very close look at the underside of your PC board to make sure there are no traces with solder blobs touching an adjacent trace. 

Check the tremolo/vibrato switch itself - does it short either circuit terminal to the switch body? 

Then I would be curious to know if the tremolo oscillator is actually running.  (I assume you don't have an oscilloscope.)
When you flip the "vibrato" on, do you get tremolo?   

Are you saying that removing the LED causes the symptoms to occur, or are you saying the symptoms will show up with or without the LED?

Sean

43

Will,

Which preamp board do you have?  It should match one of these schematics:
Schematic for Janus preamp with sliders: http://www.fenderrhodes.com/org/ch11/fig11-1.jpg
Schematic for Janus preamp with sliders, version 2: http://www.fenderrhodes.com/pdf/late-mark1-suitcase-janus1.pdf
Schematic for Janus preamp with five knobs: http://www.fenderrhodes.com/pdf/late-mark2-suitcase.pdf

The preamp board will have a part number on it.  What is it?   Something like 015244 or 018017 or 013something.


Sean

44

Awesome idea.  I just sent the link to my wife.  ...Crossing my fingers that she thinks I am worth three internet clicks.

Sean

45

Stevie Keyz,

Here are the facts:

1.  If there is no power-on LED on your Dyno power supply, then it certainly doesn't match VV's scribbled schematic.  Not knowing what circuit you are using to charge your lithium-ion batteries is not great, and possibly dangerous.

2.  Un-protected lithium-ion batteries are known to dramatically fail when over-charged.  See https://www.powerelectronictips.com/heres-what-happens-when-lithium-ion-batteries-are-drastically-overcharged/

3.  Your little 9V batteries are built with two internal batteries in series, each providing 3.7 to 4.2 volts.  So your batteries will provide 8.4 volts when fully charged (only 7% less than nominal 9V, so no biggie). 

4.  I have no idea how robust and reliable the internal protection circuitry is inside your lithium-ion rechargeable batteries.

Chargers built for lithium-ion batteries have protection circuitry that shuts off the charger when the battery reaches full charge.  Since lithium-ion batteries (when in good condition) do not drain themselves quickly (like NiCads and NiMH batteries do), there is no trickle charger used to top them up.  (Trickle charging a fully-depleted battery may not even work, and even if it did, it would take days, not hours.)

Well, anyway, I agree that I have not fixed your problem.

Sean

46

Stevie,

Using a different wall wart to power this circuit will not fix your Li-ion battery charging problem.

I assume that the circuit was designed for an AC-AC wall wart transformer, not the 15V DC supply you are using.  However, if your 15V DC supply is working, then keep it.

The 15V DC input will probably make the power-on indicator red LED run hot and bright, but as long as that LED is okay with 50mA and the resistor doesn't burn up from the 0.675 Watts (it is rated for only 0.500 Watts), AND that the input voltage is high enough that the 78M15CT regulator doesn't go into cut out, well, you are fine.*

If this were my Dyno, I would swap the current limiting resistor that feeds the power-on red indicator LED with a 1KΩ 1/2-watt resistor (the LED should light up just fine with 13.6mA).


* The input voltage to the 78M15CT regulator is supposed to be two volts higher than the output.  The spec sheet lists the "Dropout Voltage" as 2.0V.  But if the circuit isn't sputtering and shutting off, then the regulator is working fine. 


Sean

47

Stevie,

I would not use this circuit with Lithium Ion batteries.

Assuming that the scribbled schematic is correct, it is a trickle charger.  It probably was expected to charge at less than 20mA, to keep it within the safe operating limits of the green charging indicator LED.

If you want to keep your Li-Ion batteries in the Dyno, you should disconnect the charging circuit (un-solder or clip one end of the 270Ω resistor that is next to the green LED).  This way, the Lithium-Ion batteries are never connected to the trickle charger.

Get an external charger that is designed specifically for Lithium Ion batteries.

Sean

48

The little collet?  I haven't seen a replacement part available.

I have search for "collet", "locking collar", "turreted grommet" - no luck. 

Try calling Chris and Fred at Vintage Vibe, and ask if they have one sitting in the junk drawer.

You could easily install a locking collar on top of the clutch, like a Rogers Memriloc. But you would have to adjust it with an allen wrench.
1/4" stop collar - https://www.mcmaster.com/6462K12

Sean

49


Stevie,

The 15V DC wall wart will never charge a stack of two 9V (or 8.4V)  batteries to full voltage.  You will probably never see the green charging LED light up. 

Maybe if you were able to discharge your batteries so that they were down to 6V each (remarkably dead), you might be able to get 5mA of charging current through the green LED, and it would dimly illuminate.  When the batteries charge up toward 6.8V each, the charging current would stop.  (This is because each diode in the current path drops about 0.7V.)  Your wall wart charging power source has to overcome the voltage drop in the rectifying diode, the voltage drop in the green charging indicator diode, and the voltage drop in the current limiting 270Ω resistor, and the internal resistance of both batteries.

This circuit was designed in the era of NiCd batteries. 

What batteries did you buy?  Did you also buy a charger designed for those batteries?

Sean

50



Have you checked that the potentiometer is not faulty?  Take it out of circuit and make sure that it doesn't become an open circuit at some point in the rotation.

Which Janus preamp do you have?  It should match one of these schematics:
Schematic for Janus preamp with sliders: http://www.fenderrhodes.com/org/ch11/fig11-1.jpg
Schematic for Janus preamp with sliders, version 2: http://www.fenderrhodes.com/pdf/late-mark1-suitcase-janus1.pdf
Schematic for Janus preamp with five knobs: http://www.fenderrhodes.com/pdf/late-mark2-suitcase.pdf


Sean


51




http://www.fenderrhodes.com/org/ch11/fig11-10.jpg

Are the diodes good and not backwards?  See CR3 and CR4 in schematic.
That pilot light is a little neon blub, right?

Have you looked at the AC voltage at the output of the power transformer?


52

Three Hundred and Seventy Eight?

Izzatta Typo?


Sean

53
Buying / Re: wtb leg bag
« on: May 11, 2020, 06:26:11 PM »

Wow.  I am very curious.  Are you actually going to try to use a 40-year-old vinyl leg bag?  The leg bag is more difficult to use than it is worth. and I doubt it would last.

Here is what I use to safely secure the legs in the lid compartment:  make a leg bag out of an old pair of denim jeans.  I just ran downstairs to find the bag I made....  Looks like I found an old pair of pants and sewed the legs shut at the bottom.  Then I cut the pair of jeans in half to separate the legs to make two separate bags.  I also found a bag that I made out of the sleeve of a button-down dress shirt.  I guess I made that for the sustain rod. 

The jeans are much easier to load the legs into, and you just fold over the top of the jeans.  You can wrap a rag around the top end of the legs if you are worried about them scratching each other. 

Sean

54

The guts of the piano lift right out as one piece.  See chapter three of the service manual...

See http://www.fenderrhodes.com/org/manual/ch3.html
and
https://ep-forum.com/smf/index.php?topic=10252.msg57142#msg57142


55
The Fender Rhodes Electric Piano / Re: New Tine, No Sustain
« on: May 09, 2020, 03:43:27 PM »

I think you should have another go at tightening the tine block onto the tonebar.

Put the tine block into a bench vise, and use a small block of wood in your hand to push against the tonebar to keep it from turning.  Turn the wrench with the other hand, and you will get a very tight tine that is aligned with the super-short tonebar.

Sean

56

The silver color pedals were a slightly different shape than the black pedals.
See https://ep-forum.com/smf/index.php?topic=5575.msg27566#msg27566

I swear that I have a photo of the two pedal styles sitting next to each other, but I can't find it.

Anyway, I would not be excited about the chemical strippers, but there are strippers specially-made for aluminum.  Airplanes get stripped for repainting.
I wonder how badly a sandblaster would damage the surface.  There is also the boiling water trick to remove paint.

If you sand the pedal, make sure that you use sandpaper that has never touched steel or iron.  Bits of iron will get lodged in the aluminum, and it looks dull and ugly.  You will probably get some amount of sandpaper grit lodged in the aluminum as well. 

The cast aluminum pedal will probably shine up really nicely with blue polishing rouge and a cotton buffing wheel.  It won't be a perfect mirror finish, but it will look great underfoot.

Sean

57
Oh!  A stage piano.  And a beauty at that!  Covered in crud, and damaged, but not for long.

Your Fender Rhodes Stage 73 piano was built in 1970, 1971, or 1972.

Get yourself two large tables to work on.  One table to hold the action, one table to hold parts and be your workbench.
Step one would be to clean it up.   Put the piano on a more sturdy support (saw horses are ideal), then get underneath it and remove the screws that hold the keyframe to the case.  See http://www.fenderrhodes.com/org/manual/ch3.html, specifically:



Then you can slide out the action and set it on a sturdy flat table to work on it.  If the keyframe doesn't want to come loose, it is because there are more screws holding it down.  (There may be more than the four shown in the diagram above.)

Be careful when you lift the action assembly, because it looks like your harp is not screwed down to the harp supports.  When you get the action removed from the piano case, you can strip off the tolex, remove the hardware, and start sanding.  You can use the surviving end panel as a template to make a replacement for the broken piano end.  (Do you still have the piece you broke off?)

Unscrew the name rail at each end, and set it aside, then carefully remove the keys, and clean them up.  Be careful not to dislodge the felts and paper punchings that are under the keys on the balance rail.  In your vintage of piano, the cheek blocks are screwed to the key frame from underneath. 


When you get to installing new hammer tips, see chapter 9: http://www.fenderrhodes.com/org/manual/ch9.html


Remove the ridge on the hammer head that is closest to the back of the piano.


Read the service manual a few times and watch a lot of vintage vibe videos, and you will be more comfortable.
Read the technotes at http://www.fenderrhodes.com/service/technotes.html
Especially, http://www.fenderrhodes.com/service/keybed.html and http://www.fenderrhodes.com/service/action-inspection.html

Sean

58

D.

Relax.  You will be all right.  We can help you through this.  Please post some photos.

Are you saying that you ripped the side off the piano top? Or did you rip one side off the amp cab?

Chapter 3 of the service manual will show you how to remove the action from the piano top. 
See http://www.fenderrhodes.com/org/manual/toc.html

You will probably have to get in there and screw and glue a new piece of 3/4" plywood.  Find a buddy that has a table saw, and a bunch of bar clamps, and he will get it done with you.  Make sure that it is rock solid, and then re-tolex it.

Show us a photo of the wire that you are worried about, and we will explain.

Sean

59

You don't need to lube the grommets at all.  So don't.  The wax that you find near the grommets and springs is a common woodworking trick: to drive screws into hard wood, rub the screw threads on a block of wax (or soap) and the screw will be easier to turn.

I didn't know that the square hammer tips were used with all-plastic hammers.  I thought that as soon as the half-wood hammers disappeared (around 1974?), so did the square hammer tips.  Square hammer tips on half-wood hammers is a really nice combination.  I haven't seen square hammer tips on all-plastic hammers.  I didn't know.  Thus my surprise.


Sean

60
Parts, Service, Maintenance & Repairs / Re: Accessory loop and Mark 2
« on: April 26, 2020, 01:19:36 PM »



Replace the upper jack. 

Over time, the tip spring gets bent just enough that it doesn't push hard enough against the shunt button, or the button gets enough corrosion on it to lose contact.

Forgive me for being too lazy to modify my drawing to make it Rhodes-specific, but please see:
https://ep-forum.com/smf/index.php?topic=9948.msg55373#msg55373

Switchcraft 12A:  http://www.switchcraft.com/Product.aspx?ID=2699

See the Rhodes configuration of the two jacks at upper left corner of:
5-pin Janus preamp - http://www.fenderrhodes.com/org/ch11/fig11-1.jpg
5-pin Janus amp cab - http://www.fenderrhodes.com/org/ch11/fig11-3.jpg
4-pin Peterson preamp - http://www.fenderrhodes.com/org/ch11/fig11-8.jpg

Sean

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