New Rhodes preamp design PCB w/ variable tremolo?

[MrMegaEli]

I love my old fender rhodes, I’ve fixed a lot of them. I usually just make up new passive electronics if the originals are in bad condition, or leave the original passive electronics. Would anyone be willing to make an active preamp that runs of a 9V battery? It should be a pretty simple thing to do. There are some on the market, but what if we put in the GroupDIY attitude and made it high end with no IC’s? I can give an measurements for the physical layout the PCB would need to be. Rhodes pickups are around 180 ohms.

 

[hobiesound]

wouldn't a simple fet buffer/boost suffice with maybe a simple tonestack. Like the ones you have for guitar pedals.

do you have a schematic of the orignal rhodes electronics?

greetings,

Thomas

 

[MrMegaEli]

yes exactly! here’s a thread i found online: http://www.google.com/imgres?imgurl=http://i494.photobucket.com/albums/rr306/sean73key/stage_schematic-gif.gif&imgrefurl=http://www.fenderrhodes.com/forum/archives/viewtopic.php%3Ft%3D4650%26sid%3Dff20481a1878b6dd491e2c41248465d5&usg=__RgjERCFCnimZwnGC-dXQ3fNWWvw=&h=359&w=698&sz=17&hl=en&start=1&sig2=smhYSzqDx0s0_eL1WNexJw&zoom=1&tbnid=6rlKGwCL86ZSjM:&tbnh=71&tbnw=139&ei=q76YTpaRK-Ld0QG2ifG0BA&prev=/search%3Fq%3Drhodes%2B73%2Belectronics%2Bschematic%26um%3D1%26hl%3Den%26client%3Dsafari%26sa%3DN%26rls%3Den%26tbm%3Disch&um=1&itbs=1

 

[MrMegaEli]

The originals just have a wiring harness like a guitar. It would be cool to have more volume from the Rhodes, as well as tremolo! There are a few new ones made online, but there are some things I don’t like, such as PCB mounted controls. Rhodes faceplates are slightly different, so it would be much better to handwire the controls, instead of having controls that don’t fit   

IC’s are ok, as long as it sounds good. I would buy maybe 5 boards at first, for mine, a family members, and a friend, and some extras.

 

[thestudio]

I have 73 suitcase that I would to recap .......What's the best caps to use ??? The caps in this Rhodes are Motorola?

 

[thestudio]

Seems like the repair shops use cheap caps.......

 

[bkbirge]

This is a cool idea, I'd love to put a tremelo and nicer preamp in my rhodes mk II. I wonder if a miniature tube circuit would be suitable?

 

[hobiesound]

This is a cool idea, I'd love to put a tremelo and nicer preamp in my rhodes mk II. I wonder if a miniature tube circuit would be suitable?

look at the AMZ mos boost. www.tonepad.com/project.asp?id=30
Use it all the time for guitar/bass and love it.

For tremolo i really like the trem face. http://www.geofex.com/article_folders/trem_face/tremface.htm build the improved version without the millenium bypass and i really like it.

You might as well build them as pedals so you can leave your rhodes as stock.

greetings,

Thomas

 

[Hasse]

Tremolo would be nice but would'nt it bet better with a phaser? Isn't that what most people use for a "classic" Roads sound?

 

[bkbirge]

There are lots of classic Rhodes sounds but the original suitcase with built-in amp w/Tremelo is the mack daddy in my opinion, that's the one that makes me think Ray Charles. Another almost as classic to me is the Rhodes through a Dimension D on pushbutton 4. My own Rhodes often gets sent through an Oberheim/Maestro PS-1 phaser, pure juiciness. So yeah, love the phaser sound but it's not the only one.

Tremolo would be nice but would'nt it bet better with a phaser? Isn't that what most people use for a "classic" Roads sound?

 

[bkbirge]

You might as well build them as pedals so you can leave your rhodes as stock.

Probably true but I've got nice tremelo in pedal form already and I often use the TAB 71D tube di/preamp for the output, it'd just be nice to have a nicer on board setup. You know for when lugging it to gigs which I never do anyway, lol.

 

[MrMegaEli]

I think making one for the rhodes front rail would be nice too. Just volume and tremolo would be cool, than you could use it with the earlier fender Rhodes with no faceplate, and only two holes in the front rail. Or maybe I could look into getting some cool chrome front rails made at a local metal shop, once we find out what effects people want. I’m just throwing out ideas, maybe someone could explain how to hook up those two pedal designs, and put it on a single PCB. i would be willing to have PCBs made and sell them to forum members.

 

[Jim50hertz]

There are lots of classic Rhodes sounds but the original suitcase with built-in amp w/Tremelo is the mack daddy in my opinion, that's the one that makes me think Ray Charles. Another almost as classic to me is the Rhodes through a Dimension D on pushbutton 4. My own Rhodes often gets sent through an Oberheim/Maestro PS-1 phaser, pure juiciness. So yeah, love the phaser sound but it's not the only one.

Ray Charles=Wurltzer, not Rhodes, least to me. 

PS-1 for Rhodes sounds interesting, as is this whole discussion for me.  I do like my 73 straight up through a fender twin with the trem on that, but actually love it through the EA trem circuit (little noisy and gnarly but hey that works for rhodes right?), mono too, like in the 60's. 

Here's one for you, echoplex preamp, works great for guitar and sounds great with rhodes too, cleans up a lot of the muddy lower mids.

Carry on 

 

[geoff004]

I used to run my rhodes through the effects return in my CP-70 for stereo tremolo.  I always thought it sounded as good as the original rhodes trem.

The CP-70 schematic is easily found online.  I've often thought of putting it in to a stand-alone box to run with my rhodes - I'm more tempted now as I recently sold the CP.

 

[MrMegaEli]

The volume pot on the rhodes is simply an attenuator, and there is a low freq. boost pot.
The first thing I think would be cool is a boost circuit with a volume control. Than a tremolo effect and keeping the low freq. boost would be really cool. It should be possible to run this off of a 9VDC battery on a single board. I just don’t know how to do something like this.