Connecting effects pedals to a suitcase

[GetWithTheTines]

Hi, everyone. I have some effects pedals that I would like to use, but I can't figure out how to connect them. This is a '75 Mark I and has the 4-pin and 2 quarter-inch jacks on the piano. The amp/cabinet has "External", "Amplifiers", and "Stereo/Phones" jacks. Can someone please explain how I should connect my pedals and what the other jacks are for? Are they ins/outs? In what situations would I use them? Ideally, I would still be able to use the tone and tremolo controls on the pre-amp. Please don't direct me to the manual because I looked there and couldn't figure it out from that (at least not the one that's posted on the site). Thanks!

[Cormac Long]

Not speaking from actual experience here.. only ever owned a stage myself.. but from what I've read..

The pair of 1/4" jacks are the send/return fx loop before the pre-amp. So you should be able to take a loop there from the upper jack labelled "1" through your fx chain and connecting the return into "2".

This will place the fx before the pre-amp and vibrato stage. That's a high impedance passive signal and should work fine with any typical guitar stomp or fx unit.

Down south on the suitcase amp, the external amplifiers outputs 1,2 are the stereo outputs direct from the rail pre-amp. These will hence be line level outputs. They also act as inputs to the suitcase power amp from a line level source as they are parallel wired to the power amp inputs.

You could also feed an fx chain there, south of the rail preamp, but there is no return option.. only really usable if you need to have the vibrato before the desired fx and if you're routing onward to a another mixer or amp.

[GetWithTheTines]

Thanks for the information, Cormac. I actually tried connecting it the way you described; by running the top 1/4" jack (Output to Accessory) on the pre-amp through the "In" of my pedal (a ring modulator), and then returning it from the "Out" of the pedal to the bottom 1/4" jack (Input from Accessory) on the pre-amp. This is according to the diagram here: http://www.fenderrhodes.com/img/service/guides/suitcase-mark1/p2.jpg. The 4-pin power amp cable is also plugged in.

When I do that, the piano signal is fine, but when I turn on the pedal, I can barely hear the effect. When I turn the knobs of the ring mod, I can hear the frequency and rate changes, but it's barely audible, even though the level of the piano is still fine. Not only that, the quiet sound of the ring mod is constantly coming through the cabinet, not just when I play the piano. Any idea why that would happen if I have the path correct? I know the pedal is ok because I used it with a guitar.

Regarding what you said about the pre-amp, I saw that VV sells a "True Effects Loop Kit": http://www.vintagevibe.com/p-470-suitcase-true-effects-loop-kit.aspx. Here is the description: "Rhodes had what are called accessories jacks one open one closed, this way you could tap off your harp and bypass the pre amp, but you lost all controls on your pre amp when doing this. You can use this with effects, but it is not a true effects loop."

Is it true that the 1/4" jacks on the pre-amp go directly to harp and bypass the pre-amp so you lose your pre-amp controls? I really want to keep them. Do I really have to mod my suitcase pre-amp in order to keep my pre-amp controls when I use effects pedals or does my particular model not need it? Does it just mean that the kit allows you to use the vibrato/tone controls before the effects chain, but you can still use it after the chain?

Thanks!

[Cormac Long]

This is confusing.. hopefully someone can explain exactly what the original wiring does then.. but as you referenced, the manual does suggest its a loop.

The schematic shows what seems to be a simple intercept switching on the send jack "1", meaning it would break a pass-thru route of the harp signal to the 2nd jack when a plug is inserted in "1". This would imply that a return signal has exclusive ownership of the signal path to the preamp on "2".


And take this message from some years back..
http://ep-forum.com/smf/index.php?topic=3995.msg18379#msg18379
..again fits what we're expecting to happen.

Simple test.. leave "2" disconnected and try a cable in "1" and see if it cuts the preamp signal to the suitcase altogether. I would expect it to completely cut the signal.

Next test.. run a cable (guitar if you have it) into 2, leaving 1 unplugged.. I would expect guitar signal to route via preamp and suitcase, completely disconnecting the harp.

Any suitcase owners out there who can clarify if our thinking here is correct?

[GetWithTheTines]

I found a few other posts from people saying that you need to change the electronics in order to do what I would like.
http://vintagevibe.forums-free.com/how-do-i-add-effects-to-a-suitcase-t1025.html

Here is a video on YouTube demonstrating how to create the effects loop:
http://www.youtube.com/watch?v=68dM_6FU_Pc

I guess that's what this kit is: http://www.vintagevibe.com/p-470-suitcase-true-effects-loop-kit.aspx

My question is: Is this supposed to replace the electronics in the suitcase or do you have to drill holes for it?

Also, is it possible to use effects in any way without modifying the existing electronics? If not, why is it called an effects loop? If you can't use it for effects, what the heck is it for?? Very confusing.

[Abraham]

I use a wah pedal on the rail jacks and it works great, still I can use my preamp controls including tremolo.

My peterson preamp works this way: jack one is output, jack two is also output while jack one is not being used, but it turns input whenever something is plugged into #1, so you can use them as FX Loop passing the signal out from #1 trough pedal FX then back to jack #2

I couldnt tell if FX loop goes before preamp or after, I think it's before anyway, but it doesn't bypass eq & tremolo. Thats the way your suitcase is supposed to work -mine is from 1976- but someone could have modified those or else one of the jack inputs makes a bad connection.

Hope this to be helpful!

[swenz]

My 1977 works exactly as Cormac described.  When a cable is plugged into #1 (top jack) only, the sound should cut out completely on the suitcase.  That's the test I would run on your piano.  The fact that you are only getting a small amount of effect when using a pedal in the FX loop seems like maybe the #1 jack is not completely bypassing when you plug into it and you are getting the harp signal bleeding through to the preamp along with a little bit of effect coming back into jack #2?  I'm not sure how that would happen but if you pull the harp cover the back side of those jacks are completely visible so it should be fairly easy to see if there's some kind of short or bad connection.

I should clarify that I haven't actually tried using jack #2 on it's own without a cable plugged into #1 so I'm not sure if it will cause the harp signal to completely cut out to the suitcase amp.  I'll try that.

[Cormac Long]

I think Abraham confirmed earlier that Jack 2, the return on its own acts as a parallel output. This makes sense as the jacks have been described as one open and one closed... that explains what that meant

I was thinking about the symptoms again today and began to wonder if the switch on Jack 1 is shorted and not working or soldered (resoldered) incorrectly so that there is no actual signal switch taking place.

If Jack 1 does not break the hot wire continuity to Jack 2, it will short out the fx return... which would probably explain major lack of signal from the loop while the piano continues to sound fine.

The test for this.. power down the power amp or disconnect the 4/5-pin power cable. Insert jack cables into both sockets. Then using a multimeter, test the continuity between both tips on the other end of the cables. My reading is that there should be none. The Jack 1 tip should be wired to the harp hot and the jack 2 tip to the hot input to the pre-amp. If you get a continuity, then its suggesting a short.

[The Real MC]

The problem is you are connecting an unbuffered low-level send that is coming straight from the pickup coils.  And that output is not low impedance.

Most pedals are designed for low level signals like guitars or the rhodes right off the pickup coils.  That is why your wahwah pedal worked.

Your ring mod may be designed for line level signals, that "accessory 1" jack is NOT a line level signal.  If there is an impedance mismatch between the ring mod and the rhodes, you will lose signal (AKA "voltage divider").

The Rhodes preamps had to have high input impedance to get optimal coupling to the pickups.

[Cormac Long]

Good point.. what ring mod are you using GetWithTheTines?

[GetWithTheTines]

It's a Moogerfooger MF-102. Do you think that if I install the "true effects loop kit", it will fix that issue, or is it just to allow the chain to work so that the pedals can be after the pre-amp in the chain?

Regarding the test: When I plug a cable into Accessory 1 only, I can still hear the piano with the vibrato. When I plug a cable into Accessory 2 only, I can also still hear the piano with the vibrato.

I think you might be right about there being a short or bad connection. I think I'm going to bring my pre-amp to a tech this week to look at it.

Thanks for all the help! I'm pretty clueless when it comes to this.

[Cormac Long]

Going back on earlier posts.. I was convinced that a cable in accessory 1 would cut the signal to the pre-amp. Swenz confirmed this with his '77

GetWithTheTines,
   see if you can get someone with a multimeter to test the continuity as I described in my earlier post.

If you feel up to trying this yourself, we can guide you through it. Multimeters are usually inexpensive.

TBH getting the head around a multimeter is good for any Rhodes owner especially for trouble shooting pickups and wiring.

[swenz]

I'd also recommend trying the test that Cormac recommended before taking it to a tech.

The design of the switching mechanism on the #1 jack is really very simple.  If you take the harp cover off and inspect the inner part of the jack you'll see that as you plug a cable into the jack the tip of the plug will push a small metal plate out of contact with a second metal piece causing the disconnect to the #2 jack (if it's working properly).  I suspect that it may be as simple as a bent piece inside that #1 jack which may not be allowing that separation to occur when you plug a cable in.

I actually had the opposite problem on my 77'.  When I unplugged a cable from the #1 jack that small metal plate was not returning back into contact and reestablishing the connection to the other jack and I was getting no signal to the preamp.  Being as old as these things are it was just an issue of that moving metal piece needing to be forced back into it's original shape.  I just bent it a bit in order to reestablish enough tension to allow it to return fully into contact and send the harp signal through to the preamp.

[GetWithTheTines]

Thanks for all of the suggestions. I wanted to start playing right away so I just decided to bring it into a tech and he fixed it and added the true effects loop, which also enabled me to use my pre-amp (including the vibrato) with the effects :-)