Author Topic: Suitcase to Stage Conversion  (Read 589 times)

Offline Dan

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Suitcase to Stage Conversion
« on: April 27, 2019, 09:02:35 PM »
Hi,
 I was wondering what would be the best and most cost-effective way to convert a Suitcase Rhodes into a Stage version. Really this is just for the purpose of being able to take it to gigs. I read this forum post: https://ep-forum.com/smf/index.php?topic=5117.0 , but no immediate solution was presented. Vintage Vibe does sell a kit, but they are wildly expensive and out of stock.

So I was looking at two options, either drilling out a space in the left cheek block and creating a circuit similar to the one Vintage Vibe sells (this shouldn't be too hard, right?), or taking a line output from the Rhodes, but I am unsure as to how to do this. Ideally, the vibrato and bass and treble sliders should still work. By the way, this a 5 pin version.

Any advice on how to do either of these?


Thanks.

Offline sean

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Re: Suitcase to Stage Conversion
« Reply #1 on: April 28, 2019, 04:44:27 PM »


Here is the process:
1.  Leave the suitcase bottom at home.  Take the piano top with you.  :-)
1a.  Get a sturdy keyboard stand to put the Rhodes on.  Z-fold type is solid and not bouncy.


2.  Get through the gig with no sustain pedal, or get a sustain pedal and pushrod.
Build one of these:  https://ep-forum.com/smf/index.php?topic=9967.msg55489#msg55489

See https://ep-forum.com/smf/index.php?topic=9967.msg55493#msg55493 to build a sustain rod.

Put a wooden dowel on the top end of the rod.
See https://ep-forum.com/smf/index.php?topic=4991.msg24625#msg24625 for the suitcase adapter.


3:  Get a power supply so that you can use the Janus preamp that is in your suitcase piano namerail.
3.a:  If you don't want to buy or build a power supply, just use the "accessory 1" jack as an output, and ignore the preamp.

Build your own power supply: 
Smallest unit:  https://ep-forum.com/smf/index.php?topic=9706.msg53682#msg53682
Battery-powered, or other designs: https://ep-forum.com/smf/index.php?topic=9657.msg53390#msg53390


Sean

Offline Dan

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Re: Suitcase to Stage Conversion
« Reply #2 on: April 28, 2019, 08:55:10 PM »
You are a legend! Thanks so much. For the power supply box, are the two 1/4" jack outputs the left and right channels? Is there a way to make it one stereo connection?

Offline pianotuner steveo

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Re: Suitcase to Stage Conversion
« Reply #3 on: April 29, 2019, 08:20:27 AM »
No, it is not stereo without the suitcase bottom. The amp is stereo and the vibrato moves the signal back and forth between the channels, but the harp itself is mono.
1960 Wurlitzer model 700 EP
1968 Gibson G101 Combo organ
1975 Rhodes Piano Bass
1979 Wurlitzer 206A EP
1980 Wurlitzer 200A EP
1980 Wurlitzer 270 Butterfly Grand
2000 Yamaha acoustic piano
2004 Hammond XK3
2009 73A Rhodes Mark 7
2009 Korg SV-1 73
....and a few guitars...

Offline sean

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Re: Suitcase to Stage Conversion
« Reply #4 on: April 29, 2019, 11:58:35 AM »
Dan,

I would recommend leaving the separate left and right outputs available.  But if you want a stereo output on a single jack, you could install a third jack (like Switchcraft 12B) with left and right connected to tip and sleeve. 

I think if I did this, I would be worried that someone would plug in a mono cable to the stereo output, and short the output of the right channel of the preamp.  The output ICs in the preamp might survive without a fuss, but I would probably put the 680Ω resistors on the audio outputs just in case.  (These 680Ω resistors are omitted from my power supply designs, but they do appear in Harry&Co's designs.)

I cannot figure out why you would only want a stereo output on a single jack.  Stereo inputs on a single jack would be odd to find on an amp or mixer.  Do you have an amp that has one?

If what you really want is a single output, you can just use one channel from the preamp.  The tremolo would obviously be mono, but oh well, it still sounds musical.  If you mix down the left and right channels into one signal, the tremolo is somewhat less enjoyable anyway.


Sean

Offline Dan

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Re: Suitcase to Stage Conversion
« Reply #5 on: April 29, 2019, 03:12:37 PM »
I realize now this sounds silly. Sean, you're totally right, all the guitar amps used for gigs have a mono input, I realized this after posting. However, I might add a stereo jack for recording directly from. I've assembled a parts list, which I've attached at the bottom. Comes out to $75, still better than paying for the $300 Vintage Vibe one!! I switched out that expensive switch with the LED with a circular metal one from Adafruit (still ends up coming out to $10).

In terms of the perfboard, is there a board with the correct spacing for the Delta power supply? The one I have is exactly 2"x2", but I'm not sure if the spacing is correct. According to your post, you just have to drill holes where the Delta's contacts should go, right?

I'll be building this shortly, and posting pictures!

Thanks so much!!!



Parts List:
https://docs.google.com/spreadsheets/d/1FoEC6_H0jlMeJvqHhwoIr2X_0661FRPOJMIB6YsyRL4/edit?usp=sharing
« Last Edit: April 29, 2019, 03:32:04 PM by Dan »

Offline sean

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Re: Suitcase to Stage Conversion
« Reply #6 on: April 29, 2019, 05:58:22 PM »

In the Bud CU-473 box, you won't have any room to put the additional stereo jack.   Plus, a stereo jack will NOT be convenient for recording.  All recording devices will have separate inputs.  On a mixer, you will just use two channels and pan one left, pan the other right.  On a computer interface, same deal.

Your parts list looks fine.  You are paying too much for the 1/4" jacks.  I don't know why, but the stereo jacks are cheaper.  I buy a bunch of them, and when I only want a mono jack, I break off the solder lug and ring contact spring.  They break off cleanly enough.  Get the Switchcraft 12B jacks from Digikey for only $1.99 each.  Digikey SKU SC1094-ND, https://www.digikey.com/product-detail/en/switchcraft-inc/12B/SC1094-ND.  (Of course, you could simply leave the ring terminal and spring intact, and just ignore them.  They aren't hurting anyone if not connected.)   

Oh hey!  Mouser sells the mono jack for $1.86, and the stereo jack for $1.95!
https://www.mouser.com/ProductDetail/Switchcraft/11?qs=sGAEpiMZZMv0W4pxf2HiV3fTUvSc3cBdimTKwUFmO64%3D
https://www.mouser.com/ProductDetail/Switchcraft/12B?qs=sGAEpiMZZMtUpMOmSPzkH50chu3J12j2


I don't like the perfboard that you found, because it has plating on the back side.  I would use a completely bare perfboard.  Remember, you will have 120V AC current on two terminals on the back side of this board!

Looks like Digikey doesn't carry the two perfboard products in my writeup, but they have a vendor called Twin Industries that has a 4" x 5" board made of FR4 that is only $4.50, Twin P/N 7100-45.  https://www.digikey.com/product-detail/en/twin-industries/7100-45/438-1019-ND/480486    Mouser sells this too.

I can't find a board that you don't have to cut to size.

Because of the really awkward pin spacing that the Delta power supply has, you will have to drill.  Only a custom-made board would fit exactly.  Drilling new holes (some only have to be slightly expanded) will take you six seconds.  Okay, maybe a few more, but it is a simple operation.


I like the switch you found.  Looks sweet.


Sean
« Last Edit: April 29, 2019, 06:00:39 PM by sean »

Offline Dan

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Re: Suitcase to Stage Conversion
« Reply #7 on: April 29, 2019, 08:56:38 PM »
Excellent, thanks.

To keep shipping costs down, I found the box on Digi-Key:https://www.digikey.com/product-detail/en/bud-industries/CU-473/CU-473-ND/439266?WT.z_cid=ref_neda_dkc_buynow_budindustries&utm_source=ecia&utm_medium=aggregator&utm_campaign=budindustries
There's no image, but hopefully, it's the same box.

There's also this aluminum gray version:https://www.digikey.com/product-detail/en/bud-industries/CU-473-G/CU-473-G-ND/439267
I'm not sure which one here is just the normal aluminum, but I think it is the first one I mentioned.


Since the part of your post that was about painting the box was in reference to all the boxes you made, what do you end up doing for this version of the box? From the images, it looks like all you did was actually polish it down to that mirror look, correct? Did you end up spray painting it?

I'm not a master at spray painting metal, so if I was to theoretically spray point the box in a color, let's say a matte black (with the primer and all), would it stay, or get easily scratched off? Keep in mind this is something I'll be taking to gigs and putting in the electrical bag. I want to make sure if I paint the paint will be there to stay.
« Last Edit: April 29, 2019, 09:10:46 PM by Dan »

Offline sean

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Re: Suitcase to Stage Conversion
« Reply #8 on: April 30, 2019, 10:00:10 AM »

Dan,

The CU-473-G boxes are just painted gray at the factory.  The gray finish will probably get pretty scratched up during the process of cutting holes and construction.  I didn't find a durable spray paint that I liked for the top coat, and I expect the box to get scratched over the years of use.  But I bet a spray paint finish would work fine, it survives fine for guitar effects pedals.  Let it dry for days, not just overnight.

I started with the bare metal box, CU-473, and polished and polished and polished it with blue buffing compound, as explained here: https://ep-forum.com/smf/index.php?topic=9657.msg53397#msg53397

First, you have to clean up the edges of the bottom of the box, and round the corners so they line up with the corners of the box sides.  Then, sand away the major surface imperfections.  If you want a subtle straight grain under the shined surface, you can start with an abrasive wheel in your drill press.  I wasn't able to get a uniform grain pattern using a belt sander, so I stuck with the abrasive wheel.  The polished surface finish takes more time than you can believe, expect it to take days, not hours.  I find that I get sick and tired of the buffing wheel after two hours, so I did my finishes over the course of a week.  I would look at the workpiece, and think "That's good enough, I am done."  Then I would go inside and wash all the buffing wax off, and look at it, and say "Oh crap, it needs more work tomorrow."  Then I would go shower to get all the buffing wax and grit out of my hair.  If you relax and take your time, you will be happy with the outcome. 

The final result isn't perfect, but it is pretty.  It will get scratched, but the scratches don't look too bad.  It will get oxidized and a little bit dull over a few months, but it still looks good.

What ever finish you decide to apply, try it out on the bottom of the box first.  You can even try it on the inside surface of the bottom cover.

Sean

Offline vortmaxx

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Re: Suitcase to Stage Conversion
« Reply #9 on: April 30, 2019, 04:32:01 PM »
Re: the push-rod...

Sean, I still have both of the rods I made following the model you discussed here:
https://ep-forum.com/smf/index.php?topic=3834.msg36616#msg36616

Of course, having the spare means I will probably never lose the one I regularly use. But it does give me some small peace of mind knowing that if I do, I'm covered. Thanks again.